Ultrasound pretreatment of oat and barley bran contributes to the β-glucans content and technological properties of flatbread with or without sourdough

Ultrasound pretreatment of oat and barley bran contributes to the β-glucans content and technological properties of flatbread with or without sourdough | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Ultrasound pretreatment of oat and barley bran contributes to the β-glucans content and technological properties of flatbread with or without sourdough Tomislava Grgić, Roman Bleha, Petra Smrčková, Andriy Synytsya, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4280152/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Sourdough fermentation of bran can overcome the technological problems encountered in bread making but favors the activity of endogenous β-glucanase leading to a degradation of β-glucans. This study investigated the effects of high-intensity ultrasound (US) pretreatment of oat (OB) and barley (BB) bran on its β-glucans content, properties, and preservation in processing, as well as the on the acidification kinetics of bran sourdough fermentation and on its application in flatbread. To reduce β-glucanase activity, OB and BB (15 % water suspensions) were US-pretreated prior to sourdough fermentation. The acidification kinetics, the microbial viable cell count, and the total titratable acidity (TTA) of the sourdough were determined. The total β-glucans content of bran, sourdough, and bread, as well as water solubility and the molecular weight (Mw) of control and US-pretreated bran were investigated. The physical properties of control wheat and composite flatbreads were compared. The US-pretreatment increased the acidification rate (30%) and TTA (51%) of OB sourdough, however decreased the acidification rate of BB (18%). After the US-pretreatment of OB and BB, the total (11.5-12.3 %) and water-soluble β-glucans (31-40 %) increased while their Mw decreased (7-21.7 %). In sourdough and flatbread prepared with US-pretreated OB/BB, 93-95 % and 90-98 % of β-glucans were retained, respectively, compared to 64-72 % and 82-92 % in control samples. The US-pretreatment and/or sourdough fermentation of OB and BB resulted in flatbreads of higher specific volume (8-22 %) and cohesiveness (11-20%) while reduced hardness (40-55 %) and chewiness (51-73 %) compared to their control bread. acidification kinetics arabinoxylan β-glucanase activity bread quality FTIR non-starch polysaccharides Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction As the world's population grows, so does the demand for food, which necessities to optimize natural resources. Today's grain processing industry strives to minimize waste and by-products while maximizing sustainable use, e.g ., by extracting valuable compounds for new food innovations (Danciu et al., 2023; Fărcas et al., 2022; Skendi et al., 2020). Cereal bran is a milling by-product that represents a low-cost source of dietary fiber, proteins, minerals, vitamins, phenolic compounds, and other phytochemicals beneficial for human health (Danciu et al., 2023; Fărcas et al., 2022; Skendi et al., 2020). Moreover, some of them, such as oat and barley bran, are well-known for their soluble dietary fiber, denoted as mixed linkage (1 3), (1 4) β-glucans with proven health promoting properties (Danciu et al., 2023; Harland, 2015). The inclusion of 3 g of oat and barley β-glucans in the daily diet can effectively reduce post-prandial glycemic response and lower blood cholesterol levels, thereby reducing the risk of coronary heart disease (EFSA, 2011). Along with β-glucans, oat and barley bran contain hemicellulose dietary fiber, known as arabinoxylans (AX), which are also classified as non-starch polysaccharides (NSP) (Rosicka-Kaczmarek et al., 2016). AXs, being largely insoluble and resistant to monogastric enzymatic breakdown, serve as an optimal prebiotic substrate (Tiwari et al., 2019). The inclusion of bran could enhance the nutrition value of bread and improve diets of contemporary consumers, but it is often avoided due to an undesirable antinutrients content, as well as technological and sensorial impairments (Estivi et al., 2022; Grgić et al., 2024b). Problems such as increased water absorption, reduced bread volume and increased crumb hardness could be attenuated by improving the solubility of dietary fiber (Verdonck et al., 2023). Promising solution to attenuate the negative effects of bran in bread making is sourdough fermentation (Fărcas et al., 2022). Namely, in sourdough fermentation formation of organic acids and pH decline occurs, resulting with activation of different endogenous cereal enzymes or bacterial enzymes which degrade biopolymers (De Vuyst et al., 2017). Hence, sourdough fermentation of barley or oat bran was used to improve the volume, color, sensory properties and increase the concentration of soluble fiber of composite wheat bread (Banu et al., 2017; Pontonio et al., 2020; Reidzane et al., 2023; Rieder et al., 2012). The technological and nutritional properties of the white wheat bread can be improved by adding 20% pumpkin puree, 10% barley bran sourdough, 7.7% rice bran sourdough and 7% wheat bran sourdough (Ebrahimi et al., 2022). Nonetheless, Saka et al. (2021) reported that composite breads containing up to 10% oat bran have acceptable sensory properties and increased dietary fiber and phenolics content, but the texture of breads with sourdough is inferior compared to straight or sponge method. Although the fiber solubilization is mostly favorable for softening the bread texture, a lower content and Mw of β-glucans is often associated with poorer health promoting properties (Wolever et al., 2010). The endogenous β-glucanase depolymerizes β-glucans, reducing their molecular weight (Mw) but improving solubility (Gamel et al., 2015; Lu et al., 2018). The long contact time with water and the temperature conditions of fermentation favor the activity of β-glucanase. To overcome the detrimental effects of oat bran addition on wheat bread quality and to preserve the β-glucans, different times of sourdough fermentation and different particle size of oat bran (Johansson et al., 2018), as well as heat pretreatment of oat bran were explored (Rieder et al., 2012), which resulted in a reduction of β-glucans Mw by only 15% and 10%, respectively. Fermentation time is a very important parameter that directly correlates with the reduction in the β-glucans Mw (Johansson et al., 2018). However, the type of bran is also having the importance in fermentation, since it was demonstrated that the addition of oat bran can improve the acidification kinetics of oat flour, while the addition of barley bran does not affect the kinetics of barley flour (Grgić et al., 2024b). To inactivate endogenous β-glucanase and to preserve β-glucans, heat (oven heating, scalding, autoclaving) as well as chemical treatments (ethanol refluxing or the addition of organic acid salts such as calcium propionate, potassium sorbate and sodium benzoate) have been used as conventional methods (Lazaridou et al., 2014; Rieder et al., 2015; Tosh et al., 2012). Nevertheless, novel techniques such as microwave heating (Pérez-Quirce et al., 2017) are continuously being developed to avoid negative effects of conventional approaches, such as energy or chemical consumption, as well as altered nutritional, technological, and sensorial properties or consumer’s acceptance of the final products (Rieder et al., 2015). In our previous study (Grgić et al., 2023), we demonstrated a partial inactivation of the endogenous β-glucanase, degradation of phytates, and modification of functional properties of oat and barley bran due to high-intensity ultrasound (US) treatment. Nevertheless, the prospective of US-pretreatment of bran to alter enzyme activity in sourdough fermentation and bread making needs to be addressed. Ultrasound is used to aid traditional processing (germination, fermentation, and cooking) of cereal- and pseudocereal-based foods and to increase functionality of their by-products (Estivi et al., 2022; Fărcas et al., 2022; Grgić et al., 2023). Related, Luo et al. (2018) found that a proper combination of ultrasound power density (15.38-38.46 W/L) and treatment time (20-50 min), at a constant temperature of 36-38 °C, successfully reduces the fermentation time of wheat dough and improves the quality of steamed bread, i.e. lowers hardness, and increases specific volume. Similar results were reported by Zhang et al. (2022) who demonstrated that ultrasound treatment (22.5 W/L) improved dough extensibility. The ultrasonication of rice flour improved fermentative properties, as it accelerated the generation of CO 2 and retained it in the dough structure, as well as improved the viscoelastic behavior of rice flour and its bread making properties (Vela et al., 2023). Jalali et al. (2020) reported that the utilization of US-induced pre-gelatinized corn flour in bread making resulted in sensory acceptable gluten-free pan bread with reduced hardness and increased specific volume. In addition, US proved to be effective in increasing solubility of rice bran polysaccharides, making it an ideal substrate for lactic acid bacteria fermentation in nutraceutical production (Vaitkeviciene et al., 2022). However, there are no available studies on the application of US technology as a pretreatment aiming to prevent the degradation of β-glucans during sourdough fermentation and bread making process. As a continuation of our previous study (Grgić et al., 2023), here US-pretreated oat and barley bran were transferred to sourdough fermentation and subsequently used in making of flatbread. The present study therefore aimed to investigate the effects of US treatment on the content, molecular weight, and solubility of the β-glucan and NSP monosaccharide composition of oat and barley bran, the acidification kinetics of US-pretreated bran and the effects of US and sourdough on flatbread properties. The combined effect of US-pretreatment and sourdough fermentation of oat and barley bran on the quality of single-layer flatbread was tested. Materials And Methods 2.1 Materials Barley bran (Ivan Varga SME, Orehovica, Croatia) and oat bran (Eko-Jazo Ltd., Ivanovac, Croatia), which was not previously thermally treated, were purchased directly from the producers. A semi-refined wheat flour (Čakovečki mlinovi, Čakovec, Croatia) contained 0.78% ash, 11.0% protein, 11.9% moisture, and 2.3% fat, while the amylolytic activity was 1640 Brabender units (BU). Elaborate chemical composition and particle size of the semi-refined wheat flour and bran samples are presented in our previous publications (Grgić et al., 2023; 2024b). 2.2 Bran pretreatment with ultrasound Oat (OB) and barley (BB) bran was US-pretreated using an UP400St sonicator (Hielscher Ultrasonics, Germany) of a nominal output of 400 W, operating at 24 kHz with a H22D titanium probe. The optimal conditions for US-pretreatment were selected according to the desirability approach based on the results that achieved the highest β-glucanase inactivation as well as functional properties (water swelling and retention capacity) according to our previous study (Grgić et al., 2023). The overall desirability values for selected treatments were 0.529 for oat and 0.627 for barley bran. The bran samples (30 g/200 mL of water) were US-pretreated in duplicate, at an amplitude of 100%, where the selected specific energy was 217.5 kJ/kg for OB and 348 kJ/kg-P for BB (with pulse mode, 5 s of emission with 10 s pause in between). The resulting treatment time was 7 min and 36 min and the temperature at the end of treatment was 67 ± 1.4 °C for OB and 72 ± 2.8 °C for BB. The US-pretreated bran was freeze-dried (Alpha 1–4 LSCplus; Martin Christ Gefriertrocknungsanlagen GmbH, Germany) for chemical analyses or used directly for sourdough and bread making. 2.3 Extraction of non-starch polysaccharidic fractions The homogenized control (untreated) and US-pretreated OB and BB were subjected to series of washing steps to eliminate lipids, pigments, and other small molecules. To ensure thorough washing and to remove residual water, the samples underwent sequential washing firstly with hexane, and acidified ethanol (0.2 mol L -1 HCl in 80% aqueous ethanol), then with aqueous ethanol (80%, v/v) until attaining a neutral pH, and finally with ethanol (96%, v/v) and acetone. Following the washing process, the solids were re-homogenized for cold water extraction at 20 ± 2 °C (Fig. 1). 2.4 Fourier transform infrared (FTIR) measurement To investigate structural properties of OB and BB water-extractable polysaccharides (Section 2.3), the Fourier transform infrared (FTIR) spectra of the control samples and the US-pretreated samples were recorded using a Nicolet 6700 FTIR spectrometer (ThermoFisher Scientific, USA). Samples were ground into a powder along with potassium bromide (KBr for IR spectroscopy, Supelco Sigma-Aldrich, USA) in a ratio of 10:1 (v/v) and pressed into pellet using a hand press (Pike Technologies, Madison, WI, USA) prior to measurement. FTIR spectra were recorded in the spectral region of 400 – 4000 cm - ¹ with a spectral resolution 2 cm - ¹, using 64 scans. The recording was done using Omnic 8.0 software (ThermoFisher Scientific, USA) and the spectra were exported in ASCII format to Origin 6.0 software (OriginLab, USA) for graphs presentation. Each spectrum displayed represents the average of two repeated measurements taken for each sample. 2.5 Determination of monosaccharides composition The monosaccharide composition of the purified water-soluble fractions was determined in duplicates according to Passos and Coimbra (2013). The samples were hydrolyzed with 72% H 2 SO 4 (1 – 2 mg per sample), and the released monosaccharides were successively reduced, acetylated, and analyzed as alditol acetates using a gas chromatograph with flame ionization detector (GC-FID, Shimadzu GC2010, Japan) and a 30 m capillary column DB-225 (internal diameter 0.25 mm, film thickness 0.15 µm). The arabinoxylans (AX) content was estimated using the Equation (1) as described by Zambrano et al. (2023): 2.6 Determination of β-glucans content, solubility, and molecular weight The total β-glucans content was determined in bran, sourdough, and flatbread samples in duplicates according to AOAC Method 995.16 using the (Megazyme, Ireland). The content of soluble β-glucan was determined according to Vasanthan et al. (2002). After mixing 100 mg of the samples with 10 mL of deionized water in 50 mL test tubes, the sample was incubated in a shaking water bath (SBS40, Stuart, UK) at 25 °C for 2 h and centrifuged at 3225 rpm for 10 min (Multifuge X Pro, Thermo Fisher Scientific, USA). The solubilized β-glucans in the supernatant were quantified following the same method as for the total β-glucans using the Mixed-linkage β-glucan Assay Kit (Megazyme, Ireland). The water solubility of β-Glucans was calculated as the ratio of solubilized β-glucans to total β-glucans in the sample. The insoluble β-glucans were calculated as the difference between the total and soluble β-glucans. A set of control and US-pretreated bran underwent Mw analysis using a gel permeation/size exclusion (GPC/SEC) chromatography system (Omnisec Reveal) equipped with multi-angle light scattering (including low-angle light scattering and right-angle light scattering), viscosity, and refractive index detectors (Malvern Panalytical, USA). The chromatographic separation was done with 0.1 M sodium nitrate at a flow rate of 0.7 mL/min on two columns (YMC-Pack Diol-200 / S-5mm / 8´30 mm and YMC-Pack Diol-120 / S-5mm / 8´30 mm) along with a guard column (DL12S05-0308WTG, YMC, Japan). The system and columns were maintained at a temperature of 35 °C throughout the analysis. A set of Polycal pullulan/dextran standards (Malvern Panalytical, Westborough, USA) was used for calibration. The injection of both samples and standards was carried out twice, each at a volume of 100 μL. The OMNISEC software v.11.35 (Malvern Panalytical, USA) was used for controlling the chromatographic system and management of data acquisition and analysis. 2.7 Sourdough fermentation and characterization The suspension of control and US-pretreated bran (OB-US and BB-US) underwent the sourdough fermentation in duplicate as presented in Fig. 2. The US-pretreated suspension was quickly cooled to 30 °C before fermentation. The dough yield was 667 and the commercial starter LIVENDO LV4 (Lesaffre, France) (0.5% bran weight) was added. The process was carried out in an INB 500 thermostat (Memmert, Germany) at 30 °C until a pH value of approx. 4 was reached, which took 14.5 – 23 h, depending on the sample. The pH-meter equipped with a data logger (Lutron Electronic Enterprise Co., Ltd., Taiwan) was used for recording the pH value every 5 minutes during the sourdough fermentation. The acidification kinetics were modeled according to the Gompertz model Equation (2) as modified by Zwietering et al. (1990): where y is log (dpH dt −1 , units of pH min −1 ); k represents the initial level of the dependent variable; A (dpH) denotes the difference in pH (units) between the initial value and the value achieved during the stationary phase of the fermentation; μ max represents the maximum rate of acidification, λ indicates the duration (minutes) of the latency phase, and t denotes time (expressed in minutes). To determine the total titratable acidity (TTA), the suspension of sourdough (10 g) in distilled water (90 mL) was titrated with 0.1 M NaOH until a final pH of 8.5 was reached (Grgić et al., 2024b). The TTA is expressed as the mean volume of NaOH (mL) required for the duplicate titration. The viable cell count of yeasts ( Saccharomyces spp.) and lactic acid bacteria (LAB, Lactobacillus spp.) in the sourdough was assessed following ISO 7954:2002 and ISO 15214:98 standards, respectively. Each sample was and analyzed in two replicates across three decimal dilutions. Results are expressed in colony forming units (CFU) per gram of sourdough. Subsequently, the sourdough was incorporated directly into bread making or subjected to freeze-drying for analysis of total β-glucans content. 2.8 Experimental baking of flatbread The obtained sourdough was used in making a single-layer flatbread according to the formulation (Table 1) developed within the frame of Flat Bread Mine project. The amount of sourdough that was added to the mixture was adjusted so that the added bran represented 10% of the weight of the wheat flour. The amount of water added to dough was corrected for water contained in the sourdough. The flour was mixed with water for 2 min at 90 rpm (stage 1), followed by fast mixing for 5 min at 120 rpm (stage 2) in a spiral mixer (Diosna SP12, Germany). All ingredients except salt were added in the stage 1, while salt was added at the beginning of stage 2. After the bulk fermentation (room temperature, 15 min), the dough was divided into round balls (180 g) and subjected to proofing in a chamber (Wiesheu, Germany) at 25 °C, and relative humidity 80% for 1 h. The dough balls were sheeted to 4 mm thickness, with a manual roller and cut out with a cylindrical cutter (diameter 20 cm). Flatbreads were baked in triplicates at 260 °C for 2 min each side (Wiesheu, Germany). After 1.5 h of cooling at ambient conditions, breads were used in subsequent measurements. Table 1 Recipe of control wheat and composite flatbreads with oat (OB) or barley (BB) bran Ingredient Control (% based on flour weight) Oat/barley (% based on flour/bran blend weight) Wheat flour 100 90.9 Oat or barley bran 0 9.1 Water (amount adjusted to reach 500 BU) 61 65 for OB / 63.5 for BB Salt 1.5 1.5 Dry baker’s yeast 1 1 2.9 The evaluation of flatbread physical properties The measurements of all physical properties of flatbreads were done in triplicates. The volume of the breads was assessed following the AACC 10-05.01 method (AACC International, 2010). Specific volume was then computed by dividing the volume by the weight of the bread. The width of the bread was measured at two opposite points and the height at four different points using a caliper. The spread was calculated as the ratio of the average width over height obtained from these measurements. The texture profile of the breads (including the crust) was evaluated using two pieces of bread, each cut into 36 mm in diameter and then stacked on top of each other. A double-compression test (Aboshora et al., 2016) was conducted under specific conditions: a trigger force of 5 N, probe speed set at 2 mm/s before, during, and after the test, a strain of 50%, and a pause time of 30 s. This was carried out using a TA1 texture analyzer (Ametek Lloyd Instruments Ltd., UK) with a 55 mm diameter aluminum probe. The results, which encompassed hardness, chewiness, and cohesiveness of the flatbread, were processed using Nexygen PLUS Software (Ametek Lloyd Instruments Ltd., UK). The color of the upper (top) crust was measured at six points using a colorimeter (Konica Minolta CM-700d, Japan), employing the L a b system. The total color difference (TCD) between wheat control flatbread and the samples with oat/barley bran/sourdough was calculated using Equation (3): 2.10 Statistical analysis A two-way analysis of variance (ANOVA) was used to evaluate the effects of US-pretreatment, sourdough addition and their interaction on the properties of the bread. In addition to ANOVA, Tukey post-hoc test, Pearson correlation test and principal component analysis (PCA) were performed with Statistica 14 (TIBCO Software Inc., USA). Statistical significance was established at a value of p < 0.05. Results And Discussion 3.1 FTIR spectra of water-soluble polysaccharide fractions of control and ultrasonicated bran The FTIR spectra of purified water-soluble polysaccharide fractions isolated from OB and BB show differences between the control and US-pretreated samples, as well as between oat and barley (Fig. 3). In all spectra, the broad band at ~3300–3400 cm −1 corresponded to the O–H and H–O–H stretching vibrations in water and hydroxyl groups, while the narrow band at 2922–2927 cm −1 and the closed low-frequency shoulder resulted from the C–H stretching vibrations. The middle band at 1643–1647 cm −1 belongs to the scissor deformation of water molecules, and the broad absorption band at 400–800 cm −1 was due to the vibration of bound water molecules (Brubach et al., 2005). For the fraction originated from control OB, the band of amide I vibration in proteins at 1660 cm −1 overlapped the mentioned water scissor band, and the corresponding amide II band arose at 1543 cm −1 (Gholizadeh et al., 2021). Moreover, for this fraction, the contribution of protein vibrations influences band positions in the region of 1200 – 1500 cm −1 . For example, the band at 1410 cm −1 arose from symmetric stretching vibration of COO − in Asp and Glu, the band at 1382 cm −1 originated from CH3 bending in aliphatic amino acids, and two bands at 1240 and 1259 cm −1 have the contribution of the amide III vibration. Oats are rich in proteins, so some proteins are released into the cold water along with polysaccharides. Instead, barley bran contained more AX, and a water-soluble fraction of this polysaccharide contributed to the extract from control barley bran, as confirmed by monosaccharide composition analysis (see section 3.2). Intense overlapping bands at 950 – 1200 cm −1 were attributive to C–O–C, C–O, and C–C stretching vibrations in polysaccharides (Hong et al., 2021). The band observed at 897 – 899 cm −1 was assigned to the C1β–H bending vibration characteristic for β-d-xylans (Kaur et al., 2021; Robert, 2005) and β-d-glucans (Ahmad et al., 2020; Limberger-Bayer et al., 2014). The spectra of purified fractions have no other characteristic AX bands due to their relatively small contribution, while bands found at 1419 – 1425, 1377, 1157 – 1159, 1070 – 1072, and 1030 – 1032 cm −1 arose from β-d-glucan vibrations (Bai et al., 2021; Sourki et al., 2017). Several bands at 852, 762, 708, 606, 579, and 530 cm −1 observed for the ultrasonic-treated barley bran fraction originated from C1α–H bending, CH 2 deformation, and skeletal vibrations in the starch (Mikkelsen et al., 2010; Fan 2012). Native starch granules do not dissolve in cold water, but sonication partially disrupts them and thus allows releasing of starch molecules into the extract. In contrast to the results obtained in the current work, the FTIR spectra of soluble dietary fibers, which were obtained from the control and US-treated millet bran by extraction with hot water and amylolytic enzymes, showed only slight differences, indicating that this modification did not lead to detectable structural changes (Wei et al., 2022). Unfortunately, the authors did not describe the monosaccharide composition of these products. The increased resistance of millet bran to US-pretreatment influence may be associated with the peculiarities of the composition and structure of the seed coatings of this cereal compared to barley and oats. Indeed, the FTIR spectra of millet bran represented in the mentioned article significantly differ from those shown in Fig. 3 of the current work. According to Fan et al. (2022), water-soluble polysaccharides from millet bran consisted mainly of galactose, which constitutes the US-resistant galactan, while in the case of OB and BB, this is glucose derived from mixed-linkage β-glucan mostly (Section 3.2). Moreover, in the current work, the most significant spectral changes caused by US-pretreatment are associated with proteins and starch, but, as seen from the FTIR spectra reported by Wei et al. (2022), the water-soluble fractions of millet bran did not contain these components in detectable amounts. 3.2 Monosaccharides composition of water-soluble fractions extracted from oat and barley bran The total sugars, the composition of neutral monosaccharides in the purified water-extractable polysaccharide fraction, and calculated AX content are summarized in Table 2. In all samples glucose was the main monosaccharide comprising 80 – 91 mol %, followed by xylose and arabinose (from 2.4 to 6.7 – 9.2 mol % each). The dominance of these three monosaccharides indicated that β-glucans and AX were the major soluble non-starch polysaccharides. This is consistent with previous studies (Hassan et al., 2017; Mio et al., 2022). Fucose (~0.9 – 2.6 mol %) and galactose were present in lower amounts (~0.4 – 1.3 mol %) whereas mannose and rhamnose were lower than 1 mol %. The control OB was higher in glucose but lower in arabinose, xylose, galactose, and mannose than the control BB. Related, the AX content of the control BB was 178% higher compared to OB (Table 2). Similarly, the 10-fold higher AX content in barley flour compared to oat flour was found in our previous study (Grgić et al., 2024a). Following the US-pretreatment, total sugar content increased by 23% in OB, while it remained unchanged in BB (Table 2). After US-pretreatment, the changes in monosaccharides composition were small in OB (fucose was only increased), whereas the changes in BB, except for rhamnose, were substantial (Table 2). After US-pretreatment of BB, the content of glucose increased by 11%, while the content of mannose and galactose was reduced (44% and 66%, respectively). Hence, the water-extractable AX content of BB decreased by 46%, while it was not significantly affected by US in OB (Table 2). The opposite results were found previously after treatment with a pulsed electric field (PEF) in which we recorded an increase in water-extractable AX content of oat flour by 68% and in barley flour by 56% (Grgić et al., 2024a). These differences can be attributed to the lower specific energy (4.48-5.53 kJ/kg) and temperature (21.5 °C) at the end of the PEF treatment, which was less aggressive on the polysaccharides than the US-pretreatment applied in this study. Extended exposure to ultrasonic cavitation can lead to chain-breakage, i.e., complete destruction of the AX (Estivi et al., 2022). Our results indicate a high sensitivity of barley AXs to US-treatment, leading to their partial degradation and the removal of the released fragments during purification, probably due to their high solubility and a low degree of branching. Table 2 Molar ratio (%) of monosaccharides and estimated arabinoxylans content (% of the water-extractable fraction) in the fractions obtained from oat (OB) and barley bran (BB) before (C) and after ultrasound pretreatment (US) Sample/sugar OB-C BB-C OB-US BB-US Fucose 1.59 ± 0.09 b 1.36 ± 0.20 b 2.72 ± 0.14 a 0.94 ± 0.02 c Arabinose 2.77 ± 0.15 c 6.78 ± 0.01 a 2.40 ± 0.06 c 3.71 ± 0.08 b Mannose 0.46 ± 0.04 b 0.73 ± 0.01 a 0.52 ± 0.06 b 0.41 ± 0.04 b Glucose 91.08 ± 0.77 a 80.34 ± 0.29 b 87.78 ± 3.97 a 89.34 ± 0.85 a Galactose 0.97 ± 0.07 b 1.25 ± 0.01 a 0.76 ± 0.10 b 0.43 ± 0.02 c Rhamnose 0.36 ± 0.01 a 0.35 ± 0.09 a 0.36 ± 0.02 a 0.35 ± 0.01 a Xylose 2.41 ± 0.07 c 9.19 ± 0.02 a 2.93 ± 0.63 c 5.14 ± 0.25 b Total sugars (%) 58.87 ± 0.76 b 70.99 ± 2.55 a 72.36 ± 1.81 a 69.80 ± 2.34 a Arabinoxylans (%) 5.43 ± 0.26 c 15.18 ± 0.02 a 4.71 ± 0.13 c 8.17 ± 0.31 b a–c Values within the same row marked with different letters differ significantly according to Tukey’s test ( p < 0.05). 3.3 Total content, solubility, and molecular weight of β-glucans of oat and barley bran Depending on the variety, β-glucans content of BB ranges from 4.6 to 7.2 % and in OB is approx. 9.5 % (Lazaridou et al., 2007). As expected, the total β-glucans content of OB was 64 % higher than that of BB, which is in agreement with the 13% higher glucose content in OB than in BB (Table 3). The ultrasonication enhanced β-glucan extractability by 12.3% in OB and by 11.5% in BB, compared to their controls. As reported by Benito-Román et al. (2013), ultrasound treatment (962.5 kJ/L) increases β-glucans extraction from barley flour by 25%. In another study, β-d-glucan extraction yield increased (3.87%) after a short US-treatment (4.8 min, amplitude 99% and pH=5), and decreased (6%) after treatments lasting longer than 5 min (Sourki et al., 2017). These differences caused by the US-pretreatment are probably due to changes in the structure of the polysaccharides that affect their water solubility and their tendency to interact with other cereal polymers (Zannini et al., 2022). The specific energy of ultrasonic cavitation damages the cell walls, which increases water penetration and leads to the release of polysaccharides (Sourki et al., 2017). This change is of physiological importance for β-glucans, since their health promoting benefits depend on their extractability and solubility (EFSA, 2011). The Mw of β-glucans was slightly lower for BB compared to OB (Table 3). It was reported to range from 1.18×10 5 to 7.55×10 5 g/mol in barley bran (Zheng et al., 2011) and from 1.19×10 5 to 2.3×10 5 g/mol in oat bran (Åman et al., 2004), which is somewhat lower compared to our results. These differences could derive from several factors, like cereal variety, extraction conditions and measurement method. The β-glucans Mw of OB and BB decreased after US-pretreatment by 7-21.7 %, respectively. The larger degradation of β-glucans in BB could be attributed to the higher specific energy input and longer treatment time (36 min) compared to treatment of OB (7 min). Benito-Román et al. (2013) recorded a decrease in the β-glucan Mw of barley flour between 13 % and 43 % along ultrasound specific energies from 109.5 kJ/kg to 1169.5 kJ/kg, whereby the decrease in Mw was positively correlated with an increase in the specific energy of the treatment. The β-glucan Mw degradation of 13 % after a 4.5 min US treatment of hull-less barley flour was found by Sourki et al. (2017). The 10 min of US treatment of mushroom β-glucan resulted in 58.6% lower Mw (Chen et al., 2015). In our previous study (Grgić et al., 2024a) we found a decrease (9%) in the β-glucan Mw of oat flour (from 3.71 × 10 5 g mol -1 to 3.39 × 10 5 g mol -1 ) and an increase (14%) in barley flour (from 3.30 × 10 5 g mol -1 to 3.76 × 10 5 g mol -1 ) after PEF treatment, which can be explained by a less aggressive effect of this technology on the structural properties of β-glucans. The exposure of a material to a high shear force generated during ultrasonic cavitation results in a degradation of β-glucans, i.e. decrease in Mw (Benito-Román et al., 2013). Johansson et al. (2018) found that bread containing 30 % finely ground oat bran had a higher concentration of β-glucans with a lower Mw, but also had a cholesterol-lowering effect despite the lower Mw but due to the increased viscosity. Soluble β-glucans made up 54.1% of the total β-glucans in the control OB while it was 35.5% in the control BB (Table 3). The obtained results are in agreement with Gajdošová et al. (2007), who found that different varieties of oats contain 27-51% of soluble β-glucans, while for barley it is generally lower amounting to 18-39%. Lower solubility of barley β-glucans could be due to the high number of long cellotriosyl sequences (Mikkelsen et al., 2013). Our results show that the content of soluble β-glucans after US-pretreatment was higher depending on the bran type ( p =0.009); it was 31% higher in OB and 40% higher in BB, compared to control. Chen et al. (2015) found an increase of 33.5% in water solubility of ultrasound (10 min, amplitude 50-60 %) treated β-glucan obtained from mushroom Poria cocos . Furthermore, ultrasound treatment (850 kHz, 1.3 W cm -2 , 20 min, 40 °C) increased the content of water-soluble dietary fiber in rice bran for 17.5% (Vaitkeviciene et al., 2022). The recorded changes in solubility were related to the β-glucans structure modified with ultrasonication treatment i.e., lower Mw (De Vuyst et al., 2017). Table 3 Total content, solubility, and molecular weight (Mw) of β-glucans in control (C) and US-pretreated oat (OB) and barley (BB) bran Sample OB-C BB-C OB-US BB-US Total β-glucans (g/100 g d.w.) 7.45 ± 0.27 b 4.54 ± 0.02 d 8.37 ± 0.34 a 5.06 ± 0.12 c Soluble β-glucans (g/100 g d.w.) 4.03 ± 0.02 b 1.61 ± 0.06 c 6.47 ± 0.11 a 3.81 ± 0.18 b Insoluble β-glucans (g/100 g d.w.) 3.42 ± 0.02 a 2.93 ± 0.06 a 1.89 ± 0.11 b 1.25 ± 0.18 c Average Mw (×10 5 g mol -1 ) 3.02 2.81 2.81 2.20 a–d Values within the same row marked with different letters differ significantly according to Tukey’s test ( p < 0.05) 3.4 Fermentation kinetics and β-glucan content of oat and barley bran sourdough The pH changes during the 24 h of sourdough fermentation of OB and BB was well (p<0.001) fitted to the Gompertz model (Fig. 4, Table 3). The both control samples had similar acidification rate, but the pH decline in 24 h was bigger for OB (Table 3, Fig. 4). The acidification rate of OB was similar to that previously observed for oat flour, yet slower than when the bran was mixed with flour (0.17 h -1 ) (Grgić et al., 2024b). On the contrary, BB had slower acidification rate that barley flour or its blend with bran (0.34-0.32 h -1 ) (Grgić et al., 2024b), probably due to a higher dough yield (water dilution) but also different starter used in this study. In this study, the interaction between bran type and US-pretreatment affected the pH drop (A) ( p =0.04), and the acidification rate (p<0.001) of sourdough fermentation. The US-pretreatment slightly reduced the acidification rate of BB which could be due to a lowering of α-amylase activity (Grgić et al., 2024b). The optimum sourdough pH value for bread making is approx. 4, which requires a fermentation of 6 to 24 h at a temperature of 25 °C to 35 °C (De Vuyst and Neysens, 2005). To achieve a stable pH of approx. 4, 18 h of sourdough fermentation was required for BB, while it was extended to 23 h after ultrasonication (Fig. 4). For both control and ultrasonicated OB, 14.5 h was sufficient to achieve a stable pH of 4 (Fig. 4). Although the LAB count was lower in barley sourdough than in oat sourdough, the number of viable LAB and yeast cells at the end of the fermentation, regardless of US-pretreatment (Table 4), was typical for the mature sourdough (De Vuyst et al., 2017). The TTA of OB sourdough was higher (51%) after US-pretreatment compared to its control and by 158-175 % compared to both barley samples (Table 4). Sahin et al. (2021) reported the TTA of 5.92 mL 0.1 M NaOH of oat bran sourdough fermented with LAB strain Leuconostoc citreum TR116, at a dough yield of 250, for 48 h at 30°C. In our study, the TTA of the control OB sourdough was 65 % lower due to the much shorter fermentation time, but the US-pretreatment raised it to nearly the same value as observed in the long fermentation process described by Sahin et al. (2021). The addition of OB and BB to flour was shown to have a positive effect on the acidification kinetics of oat and barley flour, with increased (19%) TTA value of 7.00 for barley and 7.53 for oats, after 15 h of fermentation at 30 °C (Grgić et al., 2024b). Total β-glucans content in the control samples of OB and BB decreased by 28.7-33.9 %, whereas in the US-pretreated samples, the decrease was only 4.89-6.91 % compared to their levels before fermentation. Although the control BB exhibited lower β-glucanase activity compared to OB (9.1 MBG4 U/kg d.w. vs. 13.3 MBG4 U/kg d.w., respectively), the bigger degradation of barley β-glucans could be attributed to a longer fermentation time, since the conditions of sourdough fermentation are ideal for the β-glucanase activity. The lowering of β-glucanase activity of OB and BB (to 4.10 MBG4 U/kg d.w. or 5.86 MBG4 U/kg d.w., respectively) with US-pretreatment was reported in our previous research (Grgić et al., 2023). Hence, the content of total β-glucans was higher in sourdough from US-pretreated samples compared to sourdough from untreated bran (by 47.5% in OB and 56.7% in BB sourdough), and even slightly higher compared to untreated bran before fermentation. Previously, it was reported that the sourdough fermentation of OB with rye sourdough had no effect on β-glucans content, but significantly reduced their Mw due to the endogenous β-glucanase activity of rye and oats (Degutyte-Fomins et al., 2002). Lu et al. (2018) found a slight decrease (4.2 - 4.9 %) in β-glucans content of oat sourdough, as OB was thermally pretreated to inactivate endogenous β-glucanase before fermentation. Similarly, microwave pretreatment of rice flour inactivated the endogenous β-glucanase of rice flour and preserved the content and Mw of β-glucans in the production of gluten-free bread (Pérez-Quirce et al., 2017). Therefore, our US-pretreatment which partly inactivated β-glucanase was equally efficient as thermal or microwave treatment in preventing the degradation of β-glucans (Grgić et al., 2023). Table 4 The parameters of acidification kinetics during 24 h of fermentation according to the Gompertz model, colony forming units (CFU) of LAB and yeast, pH value at the end of fermentation, total acidity (TTA), and total β-glucans content of sourdough Sample/ parameter OB-C-SD BB-C-SD OB-US-SD BB-US-SD µ max (h -1 ) 0.10 ± 0.01 a 0.11 ± 0.01 a 0.13± 0.01 a 0.09 ± 0.00 b A (dpH) 2.04 ± 0.02 b 1.75 ± 0.02 c 2.23 ± 0.03 a 1.77 ± 0.01 c R 2 0.996 0.989 0.973 0.996 Time (h) 14.5 18 14.5 23 LAB (CFU/g) 1.63×10 9 1.42×10 8 1.23×10 9 4.35×10 8 Yeast (CFU/g) 1.77 × 10 6 1.54 × 10 6 6.15 × 10 6 1.75 × 10 6 pH 3.98 ± 0.13 a 3.90 ± 0.04 a 3.93 ± 0.16 a 3.95 ± 0.08 a TTA (mL 0.1 M NaOH) 3.85 ± 0.42 b 2.11 ± 0.15 c 5.81 ± 0.28 a 2.25 ± 0.31 c β-glucans (g/100 g d.w.) 5.40 ± 0.32 b 3.00 ± 0.1 d 7.96 ± 0.41 a 4.71 ± 0.1 c a–d Values within the same row marked with different letters differ significantly according to Tukey’s test ( p < 0.05) OB – oat bran; BB – barley bran; C – control; US – ultrasound pretreated; SD – sourdough. µ max – maximum acidification rate; A – difference in pH (units) 3.5 β -glucans content and physical properties of flatbreads The partial replacement of semi-refined wheat flour (10 %, w/w) with OB or BB, or sourdough, significantly enriched flatbreads with β -d-glucans (Table 5). As expected, the enrichment was greater after adding OB than BB, as well as after US-pretreatment, but lower after sourdough fermentation. Hence, the largest enrichment was achieved by substitution of wheat flour with OB-US (182%) compared the use of sourdough from untreated BB (only 28%). The increase in β-glucans content observed in bread mirrored the content observed in the raw material itself; the β-glucans content in bread was positively correlated ( r =0.966, p =0.03) with the β-glucans content in the sourdough. The addition of control or US-pretreated OB or BB did not significantly change the specific volume of flatbread compared to the control wheat bread (Table 5). The specific volume of composite breads was dependent on the bran type ( p =0.049) and sourdough addition (p<0.01). On average, it was higher for barley than for oat composite breads, and higher in breads with added sourdough. Similar results were obtained by Lee et al. (2020) in whose study wheat bread enriched with 5 or 10 % of wheat bran had a slightly higher specific volume, while a bran addition higher than 15% resulted in lower specific volume compared to control bread. In addition, Tiwari et al. (2013) found that the bread of acceptable quality can be produce with the substitution of wheat flour with 30% of OB, although there was a significant reduction in a specific volume. The bread specific volume is determined by the retention of gas which increases during the sourdough fermentation process due to increase in dietary fiber solubility, especially water-extractable AX (Verdonck et al., 2023). The favorable ratio of soluble to insoluble fiber in bran used in this study (40% in barley and 50 % in oat) (Grgić et al., 2023) might have helped in preserving the volume of bread with low amount of bran. This ratio was probably further improved after US (Du et al., 2019), and sourdough fermentation. US-enhanced solubility of fiber is evident from our results showing higher water-extractable AX content in oats (Table 2) and enhanced soluble β-glucans content of both bran types (Table 3). Our results are in line with several previous studies. Vela et al. (2023) showed that bread baked with US-pretreated rice flour had a significantly higher specific volume (14-25 %) than the control with untreated flour, probably due to the partial depolymerization of the starch, which leads to improved fermentation and higher production and retention of CO 2 (Vela et al., 2023). Further on, the enhanced specific volume of sourdough-type bread containing bran compared to yeast control was reported (De Vuyst et al., 2017; Martín-Garcia et al., 2021). Similarly, Pontonio et al. (2020) reported a 15-25 % increase in the specific volume of wheat bread with barley, wheat, or emmer bran sourdough. In our study, the specific volume of breads containing sourdough-fermented untreated or US-pretreated BB was significantly (p<0.001) increased (12-23 %) even compared to the wheat control bread. Nevertheless, flatbreads with added bran (13-15 %) or sourdough (6-21 %) had a higher spread ratio than the control wheat flatbread. According to Banu et al. (2017) the addition of bran (10-30 %) to wheat flour resulted in a weaker dough and possibly of bread with a higher spread ratio. Spread ratio of our flatbreads was dependent on the interaction between the bran type, US-pretreatment, and sourdough fermentation ( p =0.02). The spread ratio was reduced after adding sourdough from control OB, but it increased after adding sourdough of US-pretreated bran of both types. In contrast, the addition of unfermented US-pretreated OB or BB significantly reduced bread spread ratio compared to bread with control bran (19%, 20%, respectively) and even compared to the wheat control (by 8-9 %, respectively). There were no significant differences in redness between breads ( a * value between 0.5-1.5). As expected, bran addition slightly darkened bread color compared to the control wheat bread. The addition of OB resulted in a small TCD (<1.5), whereas the TCD of bread with BB was distinct (1.5 < TCD < 3) from the control wheat bread. The presence of various pigments in cereal bran, such as chlorophyll, carotene, and lutein, has the potential to darken the color of bread (Hu et al., 2022). The addition of OB or BB which was US-pretreated and/or sourdough fermented resulted in a very distinct TCD (> 3). It is important to notice that all sourdough breads were lighter but less yellow than the control, whereas flatbreads with OB-US or BB-US showed similar lightness L * but 2-fold higher yellowness b * compared to the wheat control flatbread. The differences in the color of the flatbread after adding sourdough could be due to a lower sugar content after fermentation, and the lower pH of the dough, which could have slowed down the polyphenol oxidase (PPO) activity and darkening of the dough (Habuš et al., 2021). Brown pigments are formed due to the activity of PPO which catalyzes the oxidation of free and reduced phenolic compounds (Olaerts et al., 2018). PPO is mainly located in cereal bran (Grgić et al., 2024b) and its activity depends on pH value (Habuš et al., 2021). Nevertheless, the bread color is formed in baking at high temperatures majorly depending on the Maillard reactions i.e ., reaction of amino acids and reducing sugars (Olaerts et al., 2018). Sourdough fermentation creates an acidic environment that reduces the availability of amino acids, while microbial activity reduces the sugar content, both limiting the Maillard reaction (Limbad et al., 2020). The US-pretreatment of bran further increased the TCD (approx. 13 %) of flatbread containing sourdough. These slightly higher L * and TCD values after bran US-pretreatment could be due to a lower α-amylase and/or PPO activity (Grgić et al., 2023, Habuš et al., 2021). Compared to the wheat control sample (FB-C), bread with added control BB or OB was harder (16-64 %) and chewier (28-46 %) (Fig. 5). Tiwari et al. (2016) recorded an increase in bread hardness of 303-567 % after replacing 50% and 70% of wheat flour with oat bran. In our study, the US-pretreatment or sourdough fermentation had both improving effect on the bread texture. The hardness and chewiness of composite flatbreads depended on the interaction between bran type and sourdough addition or US-pretreatment, as well as the interaction between sourdough fermentation and US-pretreatment (p<0.01). The cohesiveness was mainly influenced by the bran type ( p =0.03) and the interaction between sourdough and US-pretreatment ( p =0.02). It was higher for barley than oat-containing breads, or after employing US-pretreatment or sourdough fermentation but not if they were combined. After adding sourdough, the chewiness of both barley- and oat-containing flatbread was reduced by 51-57 %, while hardness was reduced (by 18%) only in oat flatbread, whereas the cohesiveness increased by 8-11 %, respectively (Fig. 5). The reduction of hardness or chewiness of oat flatbread was bigger in the case of US-pretreatment compared to sourdough fermentation. Unlike in barley composite bread, the beneficial impact of US-pretreatment prior to sourdough fermentation was evident in oat composite bread as demonstrated by a 27% reduced hardness and a 20% lower chewiness, compared to bread made with sourdough from untreated OB. Flatbread containing US-pretreated OB or BB showed lower hardness (17-48 %) and chewiness (52-66 %), while higher cohesiveness (16-18 %) even compared to the wheat control flatbread. This improvement could be attributed to the higher solubility of β-glucans (Table 3), as well as increased water swelling (42-48 %) and retention capacity (44-59 %) of OB and BB (respectively) which we reported previously (Grgić et al., 2023). According to Ma et al. (2022) pre-gelatinized starch can improve texture properties, by reducing the hardness and chewiness but increasing the cohesiveness of the bread, due to the higher water-retention capacity. i.e ., improved water content of the bread. Furtheron, the cavitation during the US-pretreatment combined with temperatures reaching 67 °C or 72 °C towards the end of the treatment, initiated the pre-gelatinization of starch. This aligns with the findings of Jalali et al. (2020), who reported that bread made with US-pregelatinized corn flour exhibited significantly reduced hardness. 3.6 Principal component analysis The first two components of the PCA with eigenvalues of 3.598 and 2.800, accounting for 80% of the total variance, were considered (Fig. 6). The first component contrasts the variables spread ratio, bread hardness, and chewiness with crust b* and cohesiveness (Fig. 6a). The second component contrasts variables specific volume, crust L* color parameter and bread cohesiveness with chewiness. The first component contrasts flatbreads containing US-pretreated OB or BB from other bread samples, while the second component separates sourdough-containing breads from other samples (Fig. 6b). The flatbreads made with untreated bran were characterized by their hardness and chewiness, breads with US-pretreated bran were depicted in β-glucans content, while all sourdough-containing flatbreads were associated with a high specific volume, spread ratio and crust lightness. Conclusion The study explored the impact of ultrasound treatment of oat and barley bran regarding the content, molecular weight and water solubility of β-glucans, alongside the nutritive and technological properties of flatbread. While ultrasonication enhanced the acidification power of oat bran, it did not have the same effect on barley bran. Ultrasound pretreatment is a useful alternative to thermal pretreatment for preventing the degradation of β-glucans in sourdough fermentation and bread making since it inactivates endogenous β-glucanase. Compared to the control wheat bread, composite flatbreads with 10% of wheat flour replaced with ultrasonically pretreated and/or sourdough fermented oat or barley bran showed improvements in specific volume, color, and texture. Although the combined effects of ultrasound and sourdough fermentation on the examined nutritional and physical properties of the flatbread was not definitively proven, they could enhance consumer acceptance. Therefore, high-intensity ultrasound is a promising technique for functional modifications of oat and barley bran, applicable in bakery and products and other foods. Future studies should focus on the shelf-life and consumer acceptance of foods incorporating ultrasonicated bran. Declarations Data availability All relevant data are shown in the manuscript. Additional data is available upon request. Conflict of Interest The authors declare no conflict of interest. The manuscript has been read and approved for submission by all authors Code availability Not applicable Author contribution Tomislava Grgić: formal analysis, data curation, writing original draft, and preparation of all tables and figures; Roman Bleha: methodology, and formal analysis; Petra Smrčková: formal analysis; Andry Synytsya: data curation, resources, writing original draft, review and editing, and revision of the manuscript; Bojana Voučko: experimental procedure, project administrator, revision of the manuscript; Nikolina Čukelj Mustač: review and editing, and revision of the manuscript; Marcela Sluková: review and editing, and revision of the manuscript; Dubravka Novotni: validation, revision of the manuscript, and supervision. All authors read the manuscript. Acknowledgement PhD student Tomislava Grgić is thankful for a received mobility grant within the Central European Exchange Program (CEEPUS) at the University of Chemistry and Technology (UCT), Prague, Czech Republic. We thank Lesaffre Adriatic Inc. for donating LivendoTM LV4 starter. Funding This paper is supported by the PRIMA program under grant agreement No 2031 project “FLAT BREAD MINE”. This project is part of the PRIMA programme, which is an Art.185 initiative supported and funded under Horizon 2020, the European Union’s Framework Programme for Research and Innovation. Disclaimer: The results and content found on this Paper / Report reflects only the author’s view. The PRIMA Foundation is not responsible for any use that may be made of the information it contains. References AACC – American Association of Cereal Chemists. (2000). Method 10-05.01 Guidelines for measurement of volume by rapeseed displacement. Approved Methods of the American Association of Cereal Chemists International, 10th ed. Saint Paul, Minnesota, USA. Aboshora, W., Lianfu, Z., Dahir, M., Qingran, M., Musa, A., Gasmalla, M. A. A., & Omar, K. A. (2016). Influence of doum (Hyphaene thebaica L.) flour addition on dough mixing properties, bread quality and antioxidant potential. Journal of Food Science and Technology , 53 (1), 591–600. https://doi.org/10.1007/s13197-015-2063-1 Ahmad, A., Anjum, F. M., Zahoor, T., Nawaz, H., Ahmed, Z. (2010). Extraction and characterization of β-d-glucan from oat for industrial utilization. International journal of biological macromolecules, 46 (3), 304-309. Åman, P., Rimsten, L., & Andersson, R. (2004). Molecular weight distribution of β-Glucan in oat-based foods. Cereal Chemistry, 81 (3), 356-360. https://doi.org/10.1094/CCHEM.2004.81.3.356 AOAC – Association of Official Analytical Chemists. (2012). Official Method 995.16 β-D-glucan in barley and oats. Official Methods of analysis of AOAC International, 19th ed. Washington, DC Bai, Y. P., Zhou, H. M., Zhu, K. R., Li, Q. (2021). Effect of thermal processing on the molecular, structural, and antioxidant characteristics of highland barley β-glucan. Carbohydrate Polymers 271. https://doi.org/10.1016/j.carbpol.2021.118416. Banu, I., Măcelaru, I., & Aprodu, I. (2017). Bioprocessing for improving the rheological properties of dough and quality of the wheat bread supplemented with oat bran. Journal of Food Processing and Preservation , 41 (5). https://doi.org/10.1111/jfpp.13112 Benito-Román, Ó., Alonso, E., & Cocero, M. J. (2013). Ultrasound-assisted extraction of β-glucans from barley. LWT , 50 (1), 57–63. https://doi.org/10.1016/j.lwt.2012.07.006 Brubach, J. B., Mermet, A., Filabozzi, A., Gerschel, A., Roy, P. (2005). Signatures of the hydrogen bonding in the infrared bands of water. The Journal of chemical physics, 122 (18). Chen, C., Wang, L., Wang, R., Luo, X., Li, Y., Li, J., Li, Y., & Chen, Z. (2018). Ultrasound-assisted extraction from defatted oat (Avena sativa L.) bran to simultaneously enhance phenolic compounds and β-glucan contents: Compositional and kinetic studies. Journal of Food Engineering , 222 , 1–10. https://doi.org/10.1016/j.jfoodeng.2017.11.002 Chen, J., Chen, L., Lin, S., Liu, C., & Cheung, P. C. K. (2015). Preparation and structural characterization of a partially depolymerized beta-glucan obtained from Poria cocos sclerotium by ultrasonic treatment. Food Hydrocolloids , 46 , 1–9. https://doi.org/10.1016/j.foodhyd.2014.12.005 Danciu, C. A., Tulbure, A., Stanciu, M. A., Antonie, I., Capatana, C., Zerbeș, M. V., Giurea, R., & Rada, E. C. (2023). Overview of the sustainable valorization of using waste and by-products in grain processing. Foods 12 (20). https://doi.org/10.3390/foods12203770 De Vuyst, L., & Neysens, P. (2005). The sourdough microflora: Biodiversity and metabolic interactions. Trends in Food Science and Technology , 16 (1–3), 43–56. https://doi.org/10.1016/j.tifs.2004.02.012 De Vuyst, L., Van Kerrebroeck, S., & Leroy, F. (2017). Microbial ecology and process technology of sourdough fermentation. Advances in Applied Microbiology , 100 , 49–160. https://doi.org/10.1016/bs.aambs.2017.02.003 Degutyte-Fomins, L., Sontag-Strohm, T., & Salovaara, H. (2002). Oat bran fermentation by rye sourdough . Cereal Chemistry, 79 (3), 345-348. https://doi.org/10.1094/CCHEM.2002.79.3.345 Du, B., Meenu, M., Liu, H., & Xu, B. (2019). A concise review on the molecular structure and function relationship of β-glucan. International Journal of Molecular Sciences , 20 (16). https://doi.org/10.3390/ijms20164032 Ebrahimi, M., Ali Noori, S. M., Sadeghi, A., Coban, O., Zanganeh, J., Ghodsmofidi, S. M., Malvandi, Z., & Raeisi, M. (2022). Application of cereal-bran sourdough to enhance technological functionality of white wheat bread supplemented with pumpkin ( Cucurbita pepo ) puree. LWT, 158 . https://doi.org/10.1016/j.lwt.2022.113079 EFSA. (2011). Scientific Opinion on the substantiation of health claims related to beta-glucans from oats and barley and maintenance of normal blood LDL-cholesterol concentrations (ID 1236, 1299), increase in satiety leading to a reduction in energy intake (ID 851, 852), reduction of post-prandial glycaemic responses (ID 821, 824), and “digestive function” (ID 850) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. (2011). EFSA Journal, 9(6). Estivi, L., Brandolini, A., Condezo-Hoyos, L., & Hidalgo, A. (2022). Impact of low-frequency ultrasound technology on physical, chemical and technological properties of cereals and pseudocereals. Ultrasonics Sonochemistry , 86. https://doi.org/10.1016/j.ultsonch.2022.106044 Fan, D., Ma, W., Wang, L., Huang, J., Zhao, J., Zhang, H., Chen, W. (2012). Determination of structural changes in microwaved rice starch using Fourier transform infrared and Raman spectroscopy. Starch‐Stärke, 64 (8), 598-606. https://doi.org/10.1002/star.201100200 Fan, S., Guo, D., Zhang, J., Yang, Y., Xue, H., Xue, T., & Bai, B. (2022). Structure, physicochemical properties, antioxidant, and hypoglycemic activities of water-soluble polysaccharides from millet bran. Journal of Food Science, 87( 12), 5263-5275. https://doi.org/10.1111/1750-3841.16362 Fărcas, A. C., Socaci, S. A., Nemes, S. A., Pop, O. L., Coldea, T. E., Fogarasi, M., Biris-Dorhoi, E. S. (2022). An update regarding the bioactive compound of cereal by-products: Health benefits and potential applications. Foods, 14 (17). https://doi.org/10.3390/nu14173470 Flander, L., Suortti, T., Katina, K., & Poutanen, K. (2011). Effects of wheat sourdough process on the quality of mixed oat-wheat bread. LWT , 44 (3), 656–664. https://doi.org/10.1016/j.lwt.2010.11.007 Gajdošová, A., Petruláková, Z., Havrlentová, M., Červená, V., Hozová, B., Šturdík, E., & Kogan, G. (2007). The content of water-soluble and water-insoluble β-d-glucans in selected oats and barley varieties. Carbohydrate Polymers , 70 (1), 46–52. https://doi.org/10.1016/j.carbpol.2007.03.001 Gamel, T.H., Abdel-Aal, E.S.M., Tosh, S.M. (2015). Effect of yeast-fermented and sour-dough making processes on physicochemical characteristics of β-glucan in whole wheat/oat bread. LWT, 60 (1), 78–85. https://doi.org/10.1016/j.lwt.2014.07.030 Gholizadeh, H., Naserian, A. A., Yari, M., Jonker, A., Yu, P. (2021). Crude protein fractionation, in situ ruminal degradability and FTIR protein molecular structures of different cultivars within barley, corn and sorghum cereal grains. Animal Feed Science and Technology, 275 , 114855. Grgić, T., Bleha, R., Smrková, P., Stulić, V., Vukušić Pavičić, T., Synytsya, A., Iveković, D., Novotni, D. (2024a). Pulsed electric field treatment of oat and barley flour: Influence on enzymes, non-starch polysaccharides, dough rheological properties and application in flat bread. Food and Bioprocess Technology Grgić, T., Drakula, S., Voučko, B., Čukelj Mustač, N., & Novotni, D. (2024b). Sourdough fermentation of oat and barley flour with bran and its application in flatbread made with no-time and dough retardation methods. Fermentation , 10 (3), 174. https://doi.org/10.3390/fermentation10030174 Grgić, T., Pavišić, Z., Maltar-Strmečki, N., Voučko, B., Čukelj Mustač, N., Ćurić, D., Le-Bail, A., & Novotni, D. (2023). Ultrasound-assisted modification of enzymatic and antioxidant activities, functional and rheological properties of oat and barley bran. Food and Bioprocess Technology , 16 (11), 2416–2429. https://doi.org/10.1007/s11947-023-03074-5 Habuš, M., Novotni, D., Gregov, M., Štifter, S., Čukelj Mustač, N., Voučko, B., & Ćurić, D. (2021). Influence of particle size reduction and high-intensity ultrasound on polyphenol oxidase, phenolics, and technological properties of wheat bran. Journal of Food Processing and Preservation , 45 (3). https://doi.org/10.1111/jfpp.15204 Harland, J. (2015). Authorised EU health claims for oat and barley grain fibre. In Sadler, M. J. (Ed.), Foods, Nutrients and Food Ingredients with Authorised EU Health Claims (pp. 97–108). Elsevier. https://doi.org/10.1016/B978-1-78242-382-9.00005-0 Hong, T., Yin, J. Y., Nie, S. P., Xie, M. Y. (2021). Applications of infrared spectroscopy in polysaccharide structural analysis: Progress, challenge and perspective. Food chemistry, 12 . https://doi.org/10.1016/j.fochx.2021.100168 https:// doi. org/ 10. 2903/j. efsa. 2011. 2207 Hu, H., Lin, H., Xiao, L., Guo, M., Yan, X., Su, X., Liu, L., & Sang, S. (2022). Impact of native form oat β-Glucan on the physical and starch digestive properties of whole oat bread. Foods , 11 (17). https://doi.org/10.3390/foods11172622 Jalali, M., Sheikholeslami, Z., Elhamirad, A. H., Haddad Khodaparast, M. H., & Karimi, M. (2020). The effect of the ultrasound process and pre-gelatinization of the corn flour on the textural, visual, and sensory properties in gluten-free pan bread. Journal of Food Science and Technology , 57 (3), 993–1002. https://doi.org/10.1007/s13197-019-04132-7 Johansson, D. P., Andersson, R., Alminger, M., Landberg, R., & Langton, M. (2018). Larger particle size of oat bran inhibits degradation and lowers extractability of β-glucan in sourdough bread – Potential implications for cholesterol-lowering properties in vivo. Food Hydrocolloids , 77 , 49–56. https://doi.org/10.1016/j.foodhyd.2017.09.016 Katina, K., Salmenkallio-Marttila, M., Partanen, R., Forssell, P., & Autio, K. (2006). Effects of sourdough and enzymes on staling of high-fibre wheat bread. LWT , 39 (5), 479–491. https://doi.org/10.1016/j.lwt.2005.03.013 Kaur, A., Singh, B., Yadav, M. P., Bhinder, S., & Singh, N. (2021). Isolation of arabinoxylan and cellulose-rich arabinoxylan from wheat bran of different varieties and their functionalities. Food Hydrocolloids, 112, 106287. Lazaridou, A., Biliaderis, C. G., Izydorczyk, M. S. (2007). Cereal Β-glucans: Structures, physical properties and physiological functions. In Biliaderis, C. G., Izydorczyk, M. S. (Eds.), Functional food carbohydrates , CRC Press. https://doi.org/10.1201/9781420003512 Lazaridou, A., Marinopoulou, A., Matsoukas, N. P., & Biliaderis, C. G. (2014). Impact of flour particle size and autoclaving on β-glucan physicochemical properties and starch digestibility of barley rusks as assessed by in vitro assays. Bioactive Carbohydrates and Dietary Fibre , 4 (1), 58–73. https://doi.org/10.1016/j.bcdf.2014.06.009 Lee, D., Kim, M. J., Kwak, H. S., & Kim, S. S. (2020). Characteristics of bread made of various substitution ratios of bran pulverized by hammer mill or jet mill. Foods , 9 (1). https://doi.org/10.3390/foods9010048 Limbad, M., Maddox, N. G., Hamid, N., & Kantono, K. (2020). Sensory and physicochemical characterization of sourdough bread prepared with a coconut water kefir starter. Foods , 9 (9). https://doi.org/10.3390/foods9091165 Limberger-Bayer, V. M., de Francisco, A., Chan, A., Oro, T., Ogliari, P. J., & Barreto, P. L. (2014). Barley β-glucans extraction and partial characterization. Food chemistry, 154 , 84-89. Lu, J., Shan, L., Xie, Y., Min, F., Gao, J., Guo, L., Ren, C., Yuan, J., Gilissen, L., & Chen, H. (2019). Effect of fermentation on content, molecule weight distribution and viscosity of β-glucans in oat sourdough. International Journal of Food Science and Technology , 54 (1), 62–67. https://doi.org/10.1111/ijfs.13902 Lu, J., Shan, L., Xie, Y., Min, F., Gao, J., Guo, L., Ren, C., Yuan, J., Gilissen, L., & Chen, H., (2018). Effect of fermentation on content, molecular weight distribution and viscosity of β-glucans in oat sourdough. International Journal of Food Science and Technology, 54 (1), 62-67. https://doi.org/10.1111/ijfs.13902 Luo, D., Wu, R., Zhang, J., Zhang, K., Xu, B., Li, P., Yuan, Y., & Li, X. (2018). Effects of ultrasound assisted dough fermentation on the quality of steamed bread. Journal of Cereal Science , 83 , 147–152. https://doi.org/10.1016/j.jcs.2018.07.016 Ma, H., Liu, M., Liang, Y., Zheng, X., Sun, L., Dang, W., Li, J., Li, L., & Liu, C. (2022). Research progress on properties of pre-gelatinized starch and its application in wheat flour products. Grain and Oil Science and Technology , 5 (2), 87–97. https://doi.org/10.1016/j.gaost.2022.01.001 Martín-Garcia, A., Riu-Aumatell, M., & López-Tamames, E. (2023). Influence of process parameters on sourdough microbiota, physical properties and sensory profile. Food Reviews International , 39 (1), 334–348. https://doi.org/10.1080/87559129.2021.1906698 Mikkelsen, M. S., Jespersen, B. M., Larsen, F. H., Blennow, A., & Engelsen, S. B. (2013). Molecular structure of large-scale extracted β-glucan from barley and oat: Identification of a significantly changed block structure in a high β-glucan barley mutant. Food Chemistry , 136 (1), 130–138. https://doi.org/10.1016/j.foodchem.2012.07.097 Mikkelsen, M. S., Jespersen, B. M., Møller, B. L., Lærke, H. N., Larsen, F. H., & Engelsen, S. B. (2010). Comparative spectroscopic and rheological studies on crude and purified soluble barley and oat β-glucan preparations. Food Research International, 43 (10), 2417-2424. Olaerts, H., Vandekerckhove, L., & Courtin, C. M. (2018). A closer look at the bread making process and the quality of bread as a function of the degree of preharvest sprouting of wheat (Triticum aestivum). Journal of Cereal Science , 80 , 188–197. https://doi.org/10.1016/j.jcs.2018.03.004 Özkaya, B., Baumgartner, B., & Özkaya, H. (2018). Effects of concentrated and dephytinized wheat bran and rice bran addition on bread properties. Journal of Texture Studies , 49 (1), 84–93. https://doi.org/10.1111/jtxs.12286 Passos, C. P., & Coimbra, M. A. (2013). Microwave superheated water extraction of polysaccharides from spent coffee grounds. Carbohydrate Polymers , 94 (1), 626–633. https://doi.org/10.1016/j.carbpol.2013.01.088 Pérez-Quirce, S., Ronda, F., Lazaridou, A., & Biliaderis, C. G. (2017). Effect of microwave radiation pretreatment of rice flour on gluten-free breadmaking and molecular size of β-Glucans in the fortified breads. Food and Bioprocess Technology , 10 (8), 1412–1421. https://doi.org/10.1007/s11947-017-1910-7 Pontonio, E., Dingeo, C., Di Cagno, R., Blandino, M., Gobbetti, M., & Rizzello, C. G. (2020). Brans from hull-less barley, emmer and pigmented wheat varieties: From by-products to bread nutritional improvers using selected lactic acid bacteria and xylanase. International Journal of Food Microbiology , 313 . https://doi.org/10.1016/j.ijfoodmicro.2019.108384 Reidzane, S., Gramatina, I., Galoburda, R., Komasilovs, V., Zacepins, A., Bljahhina, A., Kince, T., Traksmaa, A., & Klava, D. (2023). Composition of polysaccharides in hull-less barley sourdough bread and their impact on physical properties of bread. Foods , 12 (1). https://doi.org/10.3390/foods12010155 Rieder, A., Ballance, S., Løvaas, A., & Knutsen, S. H. (2015). Minimizing molecular weight reduction of β-glucan during barley bread making. LWT , 64 (2), 767–774. https://doi.org/10.1016/j.lwt.2015.06.034 Rieder, A., Holtekjølen, A. K., Sahlstrøm, S., & Moldestad, A. (2012). Effect of barley and oat flour types and sourdoughs on dough rheology and bread quality of composite wheat bread. Journal of Cereal Science , 55 (1), 44–52. https://doi.org/10.1016/j.jcs.2011.10.003 Robert, P., Marquis, M., Barron, C., Guillon, F., Saulnier, L. (2005). FT-IR investigation of cell wall polysaccharides from cereal grains. Arabinoxylan infrared assignment. Journal of Agricultural and Food Chemistry, 53 (18), 7014-7018. Rosicka-Kaczmarek, J., Komisarczyk, A., Nebesny, E., & Makowski, B. (2016). The influence of arabinoxylans on the quality of grain industry products. European Food Research and Technology, 242 (3), 295–303. https://doi.org/10.1007/s00217-015-2549-0 Sahin, A. W., Coffey, A., & Zannini, E. (2021). Functionalisation of wheat and oat bran using single-strain fermentation and its impact on techno-functional and nutritional properties of biscuits. European Food Research and Technology , 247 (7), 1825–1837. https://doi.org/10.1007/s00217-021-03755-5 Saka, M., Özkaya, B., Saka, I. (2021). The effect of bread-making methods on functional and quality characteristics of oat bran blended bread. International Journal of Gastronomy and Food Science, 26 . https://doi.org/10.1016/j.ijgfs.2021.100439 Sourki, A. H., Koocheki, A., & Elahi, M. (2017). Ultrasound-assisted extraction of β-D-glucan from hull-less barley: Assessment of physicochemical and functional properties. International Journal of Biological Macromolecules , 95 , 462–475. https://doi.org/10.1016/j.ijbiomac.2016.10.111 Tiwari, U. P., Singh, A. K., & Jha, R. (2019). Fermentation characteristics of resistant starch, arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review. Animal Nutrition, 5 (3), 217–226). https://doi.org/10.1016/j.aninu.2019.04.003 Tiwari, U., Cummins, E., Brunton, N., O’Donnell, C., & Gallagher, E. (2013). A comparison of oat flour and oat bran-based bread formulations. British Food Journal , 115 (2), 300–313. https://doi.org/10.1108/00070701311302258 Tosh, S. M., Ahmadi, L., Yip, L., Roudsari, M., & Wood, P. J. (2012). Presence of β-glucanase activity in wheat and dairy ingredients and use of organic salts as potential enzyme inhibitors. Journal of Cereal Science , 56 (3), 538–543. https://doi.org/10.1016/j.jcs.2012.08.013 Vaitkeviciene, R., Zadeike, D., Gaizauskaite, Z., Valentaviciute, K., Marksa, M., Mazdzieriene, R., Bartkiene, E., Lele, V., Juodeikiene, G., & Jakstas, V. (2022). Functionalisation of rice bran assisted by ultrasonication and fermentation for the production of rice bran–lingonberry pulp-based probiotic nutraceutical. International Journal of Food Science and Technology , 57 (3), 1462–1472. https://doi.org/10.1111/ijfs.15053 Vasanthan, T., Gaosong, J., Yeung, J., & Li, J. (2002). Dietary fiber profile of barley flour as affected by extrusion cooking. Food Chemistry, 77 (1) , 35-40. https://doi.org/10.1016/S0308-8146(01)00318-1 Vela, A. J., Villanueva, M., & Ronda, F. (2023). Physical modification caused by acoustic cavitation improves rice flour bread-making performance. LWT , 183 . https://doi.org/10.1016/j.lwt.2023.114950 Verdonck, C., De Bondt, Y., Pradal, I., Bautil, A., Langenaeken, N. A., Brijs, K., Goos, P., De Vuyst, L., & Courtin, C. M. (2023). Impact of process parameters on the specific volume of wholemeal wheat bread made using sourdough- and baker’s yeast-based leavening strategies. International Journal of Food Microbiology , 396 . https://doi.org/10.1016/j.ijfoodmicro.2023.110193 Wei, C., Ge,Y., Liu, D., Zhao, S., Wei, M., Jiliu, J., Hu, X., Quan, Z., Wu, Y., Su, Y., Wang, Y., & Cao, L. (2022). Effects of high-temperature, high-pressure, and ultrasoinic treatment on the physicochemical properties and sturcture of soluble dietary fibers of millet bran. Frontiers in Nutrition, 8. https://doi.org/10.3389/fnut.2021.820715 Wolever, T. M. S., Tosh, S. M., Gibbs, A. L., Brand-Miller, J., Duncan, A. M., Hart, V., Lamarche, B., Thomson, B. A., Duss, R., & Wood, P. J. (2010). Physicochemical properties of oat β-glucan influence its ability to reduce serum LDL cholesterol in humans: A randomized clinical trial. American Journal of Clinical Nutrition , 92 (4), 723–732. https://doi.org/10.3945/ajcn.2010.29174 Zambrano, J. A., Thyagarajan, A., Sardari, R. R. R., & Olsson, O. (2023). Characterization of high arabinoxylan oat lines identified from a mutagenized oat population. Food Chemistry , 404 . https://doi.org/10.1016/j.foodchem.2022.134687 Zhang, M., Suo, W., Deng, Y., Jiang, L., Qi, M., Liu, Y., Li, L., Wang, C., Zheng, H., & Li, H. (2022). Effect of ultrasound-assisted dough fermentation on the quality of dough and steamed bread with 50% sweet potato pulp. Ultrasonics Sonochemistry , 82 . https://doi.org/10.1016/j.ultsonch.2022.105912 Zheng, X., Li, L., & Wang, Q. (2011). Distribution and molecular characterization of β-glucans from hull-less barley bran, shorts and flour. International Journal of Molecular Sciences , 12 (3), 1563–1574. https://doi.org/10.3390/ijms12031563 Zwietering, M.H., Jongenburger, I., Rombouts, F.M., Van, K., Riet, T. Modeling of the Bacterial Growth Curve. (1990). Applied and Environmental Microbiology, 56 , 1875–1881. https://doi.org/10.1128/aem.56.6.1875-1881.1990 Table 5 Table 5 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table5.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 04 Jun, 2024 Reviews received at journal 25 May, 2024 Reviews received at journal 21 May, 2024 Reviews received at journal 08 May, 2024 Reviewers agreed at journal 29 Apr, 2024 Reviewers agreed at journal 25 Apr, 2024 Reviewers agreed at journal 23 Apr, 2024 Reviewers invited by journal 22 Apr, 2024 Editor assigned by journal 18 Apr, 2024 Submission checks completed at journal 17 Apr, 2024 First submitted to journal 17 Apr, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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07:42:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4280152/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4280152/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":55074413,"identity":"bc875808-3dbb-4c22-b8a2-1dfa0bc817cc","added_by":"auto","created_at":"2024-04-22 07:42:52","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":146922,"visible":true,"origin":"","legend":"\u003cp\u003eThe scheme of extraction and purification of water-extractable non-starch polysaccharides\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/221eab9dee5b8161306a8ee6.png"},{"id":55074416,"identity":"0ffa62d2-fa14-4c9c-b526-ec9baf20c990","added_by":"auto","created_at":"2024-04-22 07:42:52","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":108903,"visible":true,"origin":"","legend":"\u003cp\u003eThe schematic diagram of sourdough fermentation of control and US-pretreated oat and barley bran\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/2b340fea6987b0a0730560e8.png"},{"id":55074908,"identity":"ed4b0155-8f4b-4e08-a9c3-9d5c2d3d71b8","added_by":"auto","created_at":"2024-04-22 07:50:52","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":435448,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of the water-soluble polysaccharides isolated from control (C) and ultrasound (US)-treated oat and barley bran (OB, BB)\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/2d3901fecdbfdeb1e8f85fc3.png"},{"id":55074909,"identity":"6cb36262-d8a1-4387-a40b-37b6d1026fb3","added_by":"auto","created_at":"2024-04-22 07:50:52","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":668395,"visible":true,"origin":"","legend":"\u003cp\u003eAcidification kinetics fitted to the Gompertz model for control (C) and ultrasound pretreated (US) oat (OB) and barley (BB) bran\u003c/p\u003e","description":"","filename":"Fig.4.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/0ed47bc30acaf3ae1d9b5b10.png"},{"id":55075220,"identity":"9acaeda8-9338-4a26-876b-762654502fc5","added_by":"auto","created_at":"2024-04-22 07:58:53","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":128194,"visible":true,"origin":"","legend":"\u003cp\u003eTextural properties of composite flatbreads compared to wheat control\u003c/p\u003e\n\u003cp\u003eFB – flatbread; C – control wheat; BB – barley bran; OB – oat bran; SD – sourdough; US – ultrasound treated;\u003c/p\u003e\n\u003cp\u003ea–e Values marked with different letters differ significantly according to Tukey’s test (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05)\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/0671430f4bebca43dfaa8b86.png"},{"id":55074419,"identity":"3fc0ced7-de44-4533-8a90-b8b003bd51b6","added_by":"auto","created_at":"2024-04-22 07:42:53","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":816304,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea\u003c/strong\u003e) the projection of responses on the factor plane according to principal component analysis; and \u003cstrong\u003eb\u003c/strong\u003e) the projection of samples\u003c/p\u003e","description":"","filename":"Fig.6.png","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/96c9ad04e8c9f7ef4d08d92f.png"},{"id":55075548,"identity":"d444dfcd-83ce-4ca3-bbdf-cff820c676d7","added_by":"auto","created_at":"2024-04-22 08:06:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1708976,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/d4079c00-41d7-491e-afcb-02e34a32acdb.pdf"},{"id":55074415,"identity":"ea4191ea-a681-4b51-9633-21b1ac05bb2c","added_by":"auto","created_at":"2024-04-22 07:42:52","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":130500,"visible":true,"origin":"","legend":"","description":"","filename":"Table5.docx","url":"https://assets-eu.researchsquare.com/files/rs-4280152/v1/b870277ead2f52f3e424fd6e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ultrasound pretreatment of oat and barley bran contributes to the β-glucans content and technological properties of flatbread with or without sourdough","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAs the world\u0026apos;s population grows, so does the demand for food, which necessities to optimize natural resources. Today\u0026apos;s grain processing industry strives to minimize waste and by-products while maximizing sustainable use, \u003cem\u003ee.g\u003c/em\u003e., by extracting valuable compounds for new food innovations (Danciu et al., 2023; Fărcas et al., 2022; Skendi et al., 2020). Cereal bran is a milling by-product that represents a low-cost source of dietary fiber, proteins, minerals, vitamins, phenolic compounds, and other phytochemicals beneficial for human health (Danciu et al., 2023; Fărcas et al., 2022; Skendi et al., 2020). Moreover, some of them, such as oat and barley bran, are well-known for their soluble dietary fiber, denoted as mixed linkage\u0026nbsp;(1\u0026nbsp;3), (1\u0026nbsp;4)\u0026nbsp;\u0026beta;-glucans with proven health promoting properties (Danciu et al., 2023; Harland, 2015). The inclusion of 3 g of oat and barley \u0026beta;-glucans in the daily diet can effectively reduce post-prandial glycemic response and lower blood cholesterol levels, thereby reducing the risk of coronary heart disease (EFSA, 2011). Along with \u0026beta;-glucans, oat and barley bran contain hemicellulose dietary fiber, known as arabinoxylans (AX), which are also classified as non-starch polysaccharides (NSP) (Rosicka-Kaczmarek et al., 2016). \u0026nbsp;AXs, being largely insoluble and resistant to monogastric enzymatic breakdown, serve as an optimal prebiotic substrate (Tiwari et al., 2019). The inclusion of bran could enhance the nutrition value of bread and improve diets of contemporary consumers, but it is often avoided due to an undesirable antinutrients content, as well as technological and sensorial impairments (Estivi et al., 2022; Grgić et al., 2024b). Problems such as increased water absorption, reduced bread volume and increased crumb hardness could be attenuated by improving the solubility of dietary fiber (Verdonck et al., 2023).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePromising solution to attenuate the negative effects of bran in bread making is sourdough fermentation (Fărcas et al., 2022). Namely, in sourdough fermentation formation of organic acids and pH decline occurs, resulting with activation of different endogenous cereal enzymes or bacterial enzymes which degrade biopolymers (De Vuyst et al., 2017). Hence, sourdough fermentation of barley or oat bran was used to improve the volume, color, sensory properties and increase the concentration of soluble fiber of composite wheat bread (Banu et al., 2017; Pontonio et al., 2020; Reidzane et al., 2023; Rieder et al., 2012). The technological and nutritional properties of the white wheat bread can be improved by adding 20% pumpkin puree, 10% barley bran sourdough, 7.7% rice bran sourdough and 7% wheat bran sourdough (Ebrahimi et al., 2022). Nonetheless,\u0026nbsp;Saka et al. (2021) reported that composite breads containing up to 10% oat bran have acceptable sensory properties and increased dietary fiber and phenolics content, but the texture of breads with sourdough is inferior compared to straight or sponge method.\u0026nbsp;Although the fiber solubilization is mostly favorable for softening the bread texture, a lower content and Mw of \u0026beta;-glucans is often associated with poorer health promoting properties (Wolever et al., 2010). The endogenous \u0026beta;-glucanase depolymerizes \u0026beta;-glucans, reducing their molecular weight (Mw) but improving solubility (Gamel et al., 2015; Lu et al., 2018). The long contact time with water and the temperature conditions of fermentation favor the activity of \u0026beta;-glucanase. To overcome the detrimental effects of oat bran addition on wheat bread quality and to preserve the \u0026beta;-glucans, different times of sourdough fermentation and different particle size of oat bran (Johansson et al., 2018), as well as heat pretreatment of oat bran were explored (Rieder et al., 2012), which resulted in a reduction of \u0026beta;-glucans Mw by only 15% and 10%, respectively. Fermentation time is a very important parameter that directly correlates with the reduction in the \u0026beta;-glucans Mw (Johansson et al., 2018). However, the type of bran is also having the importance in fermentation, since it was demonstrated that the addition of oat bran can improve the acidification kinetics of oat flour, while the addition of barley bran does not affect the kinetics of barley flour (Grgić et al., 2024b).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo inactivate endogenous \u0026beta;-glucanase and to preserve \u0026beta;-glucans, heat (oven heating, scalding, autoclaving) as well as chemical treatments (ethanol refluxing or the addition of organic acid salts such as calcium propionate, potassium sorbate and sodium benzoate) have been used as conventional methods (Lazaridou et al., 2014; Rieder et al., 2015; Tosh et al., 2012). Nevertheless, novel techniques such as microwave heating (P\u0026eacute;rez-Quirce et al., 2017) are continuously being developed to avoid negative effects of conventional approaches, such as energy or chemical consumption, as well as altered nutritional, technological, and sensorial properties or consumer\u0026rsquo;s acceptance of the final products (Rieder et al., 2015). In our previous study (Grgić et al., 2023),\u0026nbsp;we demonstrated a partial inactivation of the endogenous \u0026beta;-glucanase, degradation of phytates, and modification of functional properties of oat and barley bran due to high-intensity ultrasound (US) treatment. Nevertheless, the prospective of US-pretreatment of bran to alter enzyme activity in sourdough fermentation and bread making needs to be addressed. Ultrasound is used to aid traditional processing (germination, fermentation, and cooking) of cereal- and pseudocereal-based foods and to increase functionality of their by-products (Estivi et al., 2022; Fărcas et al., 2022; Grgić et al., 2023). Related, Luo et al. (2018)\u0026nbsp;found that a proper combination of ultrasound power density (15.38-38.46 W/L) and treatment time (20-50 min), at a constant temperature of 36-38 \u0026deg;C, successfully reduces the fermentation time of wheat dough and improves the quality of steamed bread, i.e. lowers hardness, and increases specific volume. Similar results were reported by Zhang et al. (2022) who demonstrated that ultrasound treatment (22.5 W/L) improved dough extensibility. The ultrasonication of rice flour improved fermentative properties, as it accelerated the generation of CO\u003csub\u003e2\u003c/sub\u003e and retained it in the dough structure, as well as improved the viscoelastic behavior of rice flour and its bread making properties (Vela et al., 2023). Jalali et al. (2020) reported that the utilization of US-induced pre-gelatinized corn flour in bread making resulted in sensory acceptable gluten-free pan bread with reduced hardness and increased specific volume. In addition, US proved to be effective in increasing solubility of rice bran polysaccharides, making it an ideal substrate for lactic acid bacteria fermentation in nutraceutical production (Vaitkeviciene et al., 2022). However, there are no available studies on the application of US technology as a pretreatment aiming to prevent the degradation of \u0026beta;-glucans during sourdough fermentation and bread making process.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs a continuation of our previous study (Grgić et al., 2023), here US-pretreated oat and barley bran were transferred to sourdough fermentation and subsequently used in making of flatbread. The present study therefore aimed to investigate the effects of US treatment on the content, molecular weight, and solubility of the \u0026beta;-glucan and NSP monosaccharide composition of oat and barley bran, the acidification kinetics of US-pretreated bran and the effects of US and sourdough on flatbread properties. The combined effect of US-pretreatment and sourdough fermentation of oat and barley bran on the quality of single-layer flatbread was tested.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cp\u003e\u003cstrong\u003e2.1 Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBarley bran (Ivan Varga SME, Orehovica, Croatia) and oat bran (Eko-Jazo Ltd., Ivanovac, Croatia), which was not previously thermally treated, were purchased directly from the producers. A semi-refined wheat flour (Čakovečki mlinovi, Čakovec, Croatia) contained 0.78% ash, 11.0% protein, 11.9% moisture, and 2.3% fat, while the amylolytic activity was 1640 Brabender units (BU). Elaborate chemical composition and particle size of the semi-refined wheat flour and bran samples are presented in our previous publications (Grgić et al., 2023; 2024b).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Bran pretreatment with ultrasound\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOat (OB) and barley (BB) bran was US-pretreated using an UP400St sonicator (Hielscher Ultrasonics, Germany) of a nominal output of 400 W, operating at 24 kHz with a H22D titanium probe. The optimal conditions for US-pretreatment were selected according to the desirability approach based on the results that achieved the highest \u0026beta;-glucanase inactivation as well as functional properties (water swelling and retention capacity) according to our previous study (Grgić et al., 2023). The overall desirability values for selected treatments were 0.529 for oat and 0.627 for barley bran. The bran samples (30 g/200 mL of water) were US-pretreated in duplicate, at an amplitude of 100%, where the selected specific energy was 217.5 kJ/kg for OB and 348 kJ/kg-P for BB (with pulse mode, 5 s of emission with 10 s pause in between). The resulting treatment time was 7 min and 36 min and the temperature at the end of treatment was 67 \u0026plusmn; 1.4 \u0026deg;C for OB and 72 \u0026plusmn; 2.8 \u0026deg;C for BB. The US-pretreated bran was freeze-dried (Alpha 1\u0026ndash;4 LSCplus; Martin Christ Gefriertrocknungsanlagen GmbH, Germany) for chemical analyses or used directly for sourdough and bread making.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Extraction of non-starch polysaccharidic fractions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe homogenized control (untreated) and US-pretreated OB and BB were subjected to series of washing steps to eliminate lipids, pigments, and other small molecules. To ensure thorough washing and to remove residual water, the samples underwent sequential washing firstly with hexane, and acidified ethanol (0.2 mol L\u003csup\u003e-1\u003c/sup\u003e HCl in 80% aqueous ethanol), then with aqueous ethanol (80%, v/v) until attaining a neutral pH, and finally with ethanol (96%, v/v) and acetone. Following the washing process, the solids were re-homogenized for cold water extraction at 20 \u0026plusmn; 2 \u0026deg;C (Fig. 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Fourier transform infrared (FTIR) measurement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate structural properties of OB and BB water-extractable polysaccharides (Section 2.3), the Fourier transform infrared (FTIR) spectra of the control samples and the US-pretreated samples were recorded using a Nicolet 6700 FTIR spectrometer (ThermoFisher Scientific, USA). Samples were ground into a powder along with potassium bromide (KBr for IR spectroscopy, Supelco Sigma-Aldrich, USA) in a ratio of 10:1 (v/v) and pressed into pellet using a hand press (Pike Technologies, Madison, WI, USA) prior to measurement. FTIR spectra were recorded in the spectral region of 400 \u0026ndash; 4000 cm\u003csup\u003e-\u003c/sup\u003e\u0026sup1; with a spectral resolution 2 cm\u003csup\u003e-\u003c/sup\u003e\u0026sup1;, using 64 scans. The recording was done using Omnic 8.0 software (ThermoFisher Scientific, USA) and the spectra were exported in ASCII format to Origin 6.0 software (OriginLab, USA) for graphs presentation. Each spectrum displayed represents the average of two repeated measurements taken for each sample.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Determination of monosaccharides composition\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe monosaccharide composition of the purified water-soluble fractions was determined in duplicates according to Passos and Coimbra (2013). The samples were hydrolyzed with 72% H\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e (1 \u0026ndash; 2 mg per sample), and the released monosaccharides were successively reduced, acetylated, and analyzed as alditol acetates using a gas chromatograph with flame ionization detector (GC-FID, Shimadzu GC2010, Japan) and a 30 m capillary column DB-225 (internal diameter 0.25 mm, film thickness 0.15 \u0026micro;m).\u003c/p\u003e\n\u003cp\u003eThe arabinoxylans (AX) content was estimated using the Equation (1) as described by Zambrano et al. (2023):\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.6 Determination of \u0026beta;-glucans content, solubility, and molecular weight\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe total \u0026beta;-glucans content was determined in bran, sourdough, and flatbread samples in duplicates according to AOAC Method 995.16 using the (Megazyme, Ireland). The content of soluble \u0026beta;-glucan was determined according to Vasanthan et al. (2002). After mixing 100 mg of the samples with 10 mL of deionized water in 50 mL test tubes, the sample was incubated in a shaking water bath (SBS40, Stuart, UK) at 25 \u0026deg;C for 2 h and centrifuged at 3225 rpm for 10 min (Multifuge X Pro, Thermo Fisher Scientific, USA). The solubilized \u0026beta;-glucans in the supernatant were quantified following the same method as for the total \u0026beta;-glucans using the Mixed-linkage \u0026beta;-glucan Assay Kit (Megazyme, Ireland). The water solubility of \u0026beta;-Glucans was calculated as the ratio of solubilized \u0026beta;-glucans to total \u0026beta;-glucans in the sample. The insoluble \u0026beta;-glucans were calculated as the difference between the total and soluble \u0026beta;-glucans.\u003c/p\u003e\n\u003cp\u003eA set of control and US-pretreated bran underwent Mw analysis using a gel permeation/size exclusion (GPC/SEC) chromatography system (Omnisec Reveal) equipped with multi-angle light scattering (including low-angle light scattering and right-angle light scattering), viscosity, and refractive index detectors (Malvern Panalytical, USA). The chromatographic separation was done with 0.1 M sodium nitrate at a flow rate of 0.7 mL/min on two columns (YMC-Pack Diol-200 / S-5mm / 8\u0026acute;30 mm and YMC-Pack Diol-120 / S-5mm / 8\u0026acute;30 mm) along with a guard column (DL12S05-0308WTG, YMC, Japan). The system and columns were maintained at a temperature of 35 \u0026deg;C throughout the analysis. A set of Polycal pullulan/dextran standards (Malvern Panalytical, Westborough, USA) was used for calibration. The injection of both samples and standards was carried out twice, each at a volume of 100 \u0026mu;L. The OMNISEC software v.11.35 (Malvern Panalytical, USA) was used for controlling the chromatographic system and management of data acquisition and analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;2.7 Sourdough fermentation and characterization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe suspension of control and US-pretreated bran (OB-US and BB-US) underwent the sourdough fermentation in duplicate as presented in Fig. 2. The US-pretreated suspension was quickly cooled to 30 \u0026deg;C before fermentation. The dough yield was 667 and the commercial starter LIVENDO LV4 (Lesaffre, France) (0.5% bran weight) was added. The process was carried out in an INB 500 thermostat (Memmert, Germany) at 30 \u0026deg;C until a pH value of approx. 4 was reached, which took 14.5 \u0026ndash; 23 h, depending on the sample. The pH-meter equipped with a data logger (Lutron Electronic Enterprise Co., Ltd., Taiwan) was used for recording the pH value every 5 minutes during the sourdough fermentation. The acidification kinetics were modeled according to the Gompertz model Equation (2) as modified by Zwietering et al. (1990):\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003ewhere y is log (dpH dt\u003csup\u003e\u0026minus;1\u003c/sup\u003e, units of pH min\u003csup\u003e\u0026minus;1\u003c/sup\u003e); k represents the initial level of the dependent variable; A (dpH) denotes the difference in pH (units) between the initial value and the value achieved during the stationary phase of the fermentation; \u0026mu;\u003csub\u003emax\u003c/sub\u003e represents the maximum rate of acidification, \u0026lambda; indicates the duration (minutes) of the latency phase, and t denotes time (expressed in minutes).\u003c/p\u003e\n\u003cp\u003eTo determine the total titratable acidity (TTA), the suspension of sourdough (10 g) in distilled water (90 mL) was titrated with 0.1 M NaOH until a final pH of 8.5 was reached (Grgić et al., 2024b). The TTA is expressed as the mean volume of NaOH (mL) required for the duplicate titration.\u003c/p\u003e\n\u003cp\u003eThe viable cell count of yeasts (\u003cem\u003eSaccharomyces\u003c/em\u003e spp.) and lactic acid bacteria (LAB,\u003cem\u003e\u0026nbsp;Lactobacillus\u003c/em\u003e spp.) in the sourdough was assessed following ISO 7954:2002 and ISO 15214:98 standards, respectively. Each sample was and analyzed in two replicates across three decimal dilutions. Results are expressed in colony forming units (CFU) per gram of sourdough. Subsequently, the sourdough was incorporated directly into bread making or subjected to freeze-drying for analysis of total \u0026beta;-glucans content.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.8 Experimental baking of flatbread\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe obtained sourdough was used in making a single-layer flatbread according to the formulation (Table 1) developed within the frame of Flat Bread Mine project. The amount of sourdough that was added to the mixture was adjusted so that the added bran represented 10% of the weight of the wheat flour. The amount of water added to dough was corrected for water contained in the sourdough.\u0026nbsp;The flour was mixed with water for 2 min at 90 rpm (stage 1), followed by fast mixing for 5 min at 120 rpm (stage 2) in a spiral mixer (Diosna SP12, Germany). All ingredients except salt were added in the stage 1, while salt was added at the beginning of stage 2. After the bulk fermentation (room temperature, 15 min), the dough was divided into round balls (180 g) and subjected to proofing in a chamber (Wiesheu, Germany) at 25 \u0026deg;C, and relative humidity 80% for 1 h. \u0026nbsp;The dough balls were sheeted to 4 mm thickness, with a manual roller and cut out\u0026nbsp;with a cylindrical cutter (diameter 20 cm). Flatbreads were baked in triplicates at 260 \u0026deg;C for 2 min each side (Wiesheu, Germany). After 1.5 h of cooling at ambient conditions, breads were used in subsequent measurements.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Recipe of control wheat and composite flatbreads with oat (OB) or barley (BB) bran\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eIngredient\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003eControl (% based on flour weight)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003eOat/barley (% based on flour/bran blend weight)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eWheat flour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003e90.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eOat or barley bran\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003e9.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eWater\u003c/p\u003e\n \u003cp\u003e(amount adjusted to reach 500 BU)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003e65 for OB /\u003c/p\u003e\n \u003cp\u003e63.5 for BB\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eSalt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"43.54304635761589%\"\u003e\n \u003cp\u003eDry baker\u0026rsquo;s yeast\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.980132450331126%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.47682119205298%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u003c/strong\u003e\u003cstrong\u003e2.9 The evaluation of flatbread physical properties\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe measurements of all physical properties of flatbreads were done in triplicates.\u003c/p\u003e\n\u003cp\u003eThe volume of the breads was assessed following the AACC 10-05.01 method (AACC International, 2010). Specific volume was then computed by dividing the volume by the weight of the bread.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;The width of the bread was measured at two opposite points and the height at four different points using a caliper. The spread was calculated as the ratio of the average width over height obtained from these measurements.\u003c/p\u003e\n\u003cp\u003eThe texture profile of the breads (including the crust) was evaluated using two pieces of bread, each cut into 36 mm in diameter and then stacked on top of each other. A double-compression test (Aboshora et al., 2016) was conducted under specific conditions: a trigger force of 5 N, probe speed set at 2 mm/s before, during, and after the test, a strain of 50%, and a pause time of 30 s. This was carried out using a TA1 texture analyzer (Ametek Lloyd Instruments Ltd., UK) with a 55 mm diameter aluminum probe. The results, which encompassed hardness, chewiness, and cohesiveness of the flatbread, were processed using Nexygen PLUS Software (Ametek Lloyd Instruments Ltd., UK).\u003c/p\u003e\n\u003cp\u003eThe color of the upper (top) crust\u003cem\u003e\u0026nbsp;\u003c/em\u003ewas measured at six points using a colorimeter (Konica Minolta CM-700d, Japan), employing the \u003cem\u003eL a b\u003c/em\u003e system. The total color difference (TCD) between wheat control flatbread and the samples with oat/barley bran/sourdough was calculated using Equation (3):\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.10 Statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA two-way analysis of variance (ANOVA) was used to evaluate the effects of US-pretreatment, sourdough addition and their interaction on the properties of the bread. In addition to ANOVA, Tukey post-hoc test, Pearson correlation test and principal component analysis (PCA) were performed with Statistica 14 (TIBCO Software Inc., USA). Statistical significance was established at a value of \u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05.\u003c/p\u003e"},{"header":"Results And Discussion","content":"\u003cp\u003e\u003cstrong\u003e3.1 FTIR spectra of water-soluble polysaccharide fractions of control and ultrasonicated bran\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe FTIR spectra of purified water-soluble polysaccharide fractions isolated from OB and BB show differences between the control and US-pretreated samples, as well as between oat and barley (Fig. 3). In all spectra, the broad band at ~3300\u0026ndash;3400 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e corresponded to the O\u0026ndash;H and H\u0026ndash;O\u0026ndash;H stretching vibrations in water and hydroxyl groups, while the narrow band at 2922\u0026ndash;2927 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e and the closed low-frequency shoulder resulted from the C\u0026ndash;H stretching vibrations. The middle band at 1643\u0026ndash;1647 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e belongs to the scissor deformation of water molecules, and the broad absorption band at 400\u0026ndash;800 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e was due to the vibration of bound water molecules (Brubach et al., 2005).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor the fraction originated from control OB, the band of amide I vibration in proteins at 1660 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e overlapped the mentioned water scissor band, and the corresponding amide II band arose at 1543 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e (Gholizadeh et al., 2021). Moreover, for this fraction, the contribution of protein vibrations influences band positions in the region of 1200 \u0026ndash; 1500 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e. For example, the band at 1410 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e arose from symmetric stretching vibration of COO\u003csup\u003e\u0026minus;\u003c/sup\u003e in Asp and Glu, the band at 1382 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e originated from CH3 bending in aliphatic amino acids, and two bands at 1240 and 1259 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e have the contribution of the amide III vibration. Oats are rich in proteins, so some proteins are released into the cold water along with polysaccharides. Instead, barley bran contained more AX, and a water-soluble fraction of this polysaccharide contributed to the extract from control barley bran, as confirmed by monosaccharide composition analysis (see section 3.2).\u003c/p\u003e\n\u003cp\u003eIntense overlapping bands at 950 \u0026ndash; 1200 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e were attributive to C\u0026ndash;O\u0026ndash;C, C\u0026ndash;O, and C\u0026ndash;C stretching vibrations in polysaccharides (Hong et al., 2021). The band observed at 897 \u0026ndash; 899 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e was assigned to the C1\u0026beta;\u0026ndash;H bending vibration characteristic for \u0026beta;-d-xylans (Kaur et al., 2021; Robert, 2005) and \u0026beta;-d-glucans (Ahmad et al., 2020; Limberger-Bayer et al., 2014). The spectra of purified fractions have no other characteristic AX bands due to their relatively small contribution, while bands found at 1419 \u0026ndash; 1425, 1377, 1157 \u0026ndash; 1159, 1070 \u0026ndash; 1072, and 1030 \u0026ndash; 1032 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e arose from \u0026beta;-d-glucan vibrations (Bai et al., 2021; Sourki et al., 2017). Several bands at 852, 762, 708, 606, 579, and 530 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e observed for the ultrasonic-treated barley bran fraction originated from C1\u0026alpha;\u0026ndash;H bending, CH\u003csub\u003e2\u003c/sub\u003e deformation, and skeletal vibrations in the starch (Mikkelsen et al., 2010; Fan 2012). Native starch granules do not dissolve in cold water, but sonication partially disrupts them and thus allows releasing of starch molecules into the extract.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn contrast to the results obtained in the current work, the FTIR spectra of soluble dietary fibers, which were obtained from the control and US-treated millet bran by extraction with hot water and amylolytic enzymes, showed only slight differences, indicating that this modification did not lead to detectable structural changes (Wei et al., 2022). Unfortunately, the authors did not describe the monosaccharide composition of these products. The increased resistance of millet bran to US-pretreatment influence may be associated with the peculiarities of the composition and structure of the seed coatings of this cereal compared to barley and oats. Indeed, the FTIR spectra of millet bran represented in the mentioned article significantly differ from those shown in Fig. 3 of the current work. According to Fan et al. (2022), water-soluble polysaccharides from millet bran consisted mainly of galactose, which constitutes the US-resistant galactan, while in the case of OB and BB, this is glucose derived from mixed-linkage \u0026beta;-glucan mostly (Section 3.2). Moreover, in the current work, the most significant spectral changes caused by US-pretreatment are associated with proteins and starch, but, as seen from the FTIR spectra reported by Wei et al. (2022), the water-soluble fractions of millet bran did not contain these components in detectable amounts.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;3.2 Monosaccharides composition of water-soluble fractions extracted from oat and barley bran\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe total sugars, the composition of neutral monosaccharides in the purified water-extractable polysaccharide fraction, and calculated AX content are summarized in Table 2. In all samples glucose was the main monosaccharide comprising 80 \u0026ndash; 91 mol %, followed by xylose and arabinose (from 2.4 to 6.7 \u0026ndash; 9.2 mol % each). The dominance of these three monosaccharides indicated that \u0026beta;-glucans and AX were the major soluble non-starch polysaccharides. This is consistent with previous studies (Hassan et al., 2017; Mio et al., 2022). Fucose (~0.9 \u0026ndash; 2.6 mol %) and galactose were present in lower amounts (~0.4 \u0026ndash; 1.3 mol %) whereas mannose and rhamnose were lower than 1 mol %. The control OB was higher in glucose but lower in arabinose, xylose, galactose, and mannose than the control BB. Related, the AX content of the control BB was 178% higher compared to OB (Table 2). Similarly, the 10-fold higher AX content in barley flour compared to oat flour was found in our previous study (Grgić et al., 2024a).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFollowing the US-pretreatment, total sugar content increased by 23% in OB, while it remained unchanged in BB (Table 2). After US-pretreatment, the changes in monosaccharides composition were small in OB (fucose was only increased), whereas the changes in BB, except for rhamnose, were substantial (Table 2). After US-pretreatment of BB, the content of glucose increased by 11%, while the content of mannose and galactose was reduced (44% and 66%, respectively). Hence, the water-extractable AX content of BB decreased by 46%, while it was not significantly affected by US in OB (Table 2). The opposite results were found previously after treatment with a pulsed electric field (PEF) in which we recorded an increase in water-extractable AX content of oat flour by 68% and in barley flour by 56% (Grgić et al., 2024a). These differences can be attributed to the lower specific energy (4.48-5.53 kJ/kg) and temperature (21.5 \u0026deg;C) at the end of the PEF treatment, which was less aggressive on the polysaccharides than the US-pretreatment applied in this study. Extended exposure to ultrasonic cavitation can lead to chain-breakage, i.e., complete destruction of the AX (Estivi et al., 2022). Our results indicate a high sensitivity of barley AXs to US-treatment, leading to their partial degradation and the removal of the released fragments during purification, probably due to their high solubility and a low degree of branching.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e Molar ratio (%) of monosaccharides and estimated arabinoxylans content (% of the water-extractable fraction) in the fractions obtained from oat (OB) and barley bran (BB) before (C) and after ultrasound pretreatment (US)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eSample/sugar\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003eOB-C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003eBB-C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003eOB-US\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003eBB-US\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eFucose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e1.59 \u0026plusmn; 0.09\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e1.36 \u0026plusmn; 0.20\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e2.72 \u0026plusmn; 0.14\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.94 \u0026plusmn; 0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eArabinose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e2.77 \u0026plusmn; 0.15\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e6.78 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e2.40 \u0026plusmn; 0.06\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e3.71 \u0026plusmn; 0.08\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eMannose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.46 \u0026plusmn; 0.04\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.73 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.52 \u0026plusmn; 0.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.41 \u0026plusmn; 0.04\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eGlucose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e91.08 \u0026plusmn; 0.77\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e80.34 \u0026plusmn; 0.29\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e87.78 \u0026plusmn; 3.97\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e89.34 \u0026plusmn; 0.85\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eGalactose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.97 \u0026plusmn; 0.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e1.25 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.76 \u0026plusmn; 0.10\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.43 \u0026plusmn; 0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eRhamnose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.36 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.35 \u0026plusmn; 0.09\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.36 \u0026plusmn; 0.02\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e0.35 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eXylose\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e2.41 \u0026plusmn; 0.07\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e9.19 \u0026plusmn; 0.02\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e2.93 \u0026plusmn; 0.63\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e5.14 \u0026plusmn; 0.25\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eTotal sugars (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e58.87 \u0026plusmn; 0.76\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e70.99 \u0026plusmn; 2.55\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e72.36 \u0026plusmn; 1.81\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e69.80 \u0026plusmn; 2.34\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"34.69387755102041%\"\u003e\n \u003cp\u003eArabinoxylans (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e5.43 \u0026plusmn; 0.26\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e15.18 \u0026plusmn; 0.02\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e4.71 \u0026plusmn; 0.13\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.3265306122449%\"\u003e\n \u003cp\u003e8.17 \u0026plusmn; 0.31\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea\u0026ndash;c Values within the same row marked with different letters differ significantly according to Tukey\u0026rsquo;s test (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Total content, solubility, and molecular weight of \u0026beta;-glucans of oat and barley bran\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDepending on the variety, \u0026beta;-glucans content of BB ranges from 4.6 to 7.2 % and in OB is approx. 9.5 % (Lazaridou et al., 2007). As expected, the total \u0026beta;-glucans content of OB was 64 % higher than that of BB, which is in agreement with the 13% higher glucose content in OB than in BB (Table 3). The ultrasonication enhanced \u0026beta;-glucan extractability by 12.3% in OB and by 11.5% in BB, compared to their controls. As reported by Benito-Rom\u0026aacute;n et al. (2013), ultrasound treatment (962.5 kJ/L) increases \u0026beta;-glucans extraction from barley flour by 25%. In another study, \u0026beta;-d-glucan extraction yield increased (3.87%) after a short US-treatment (4.8 min, amplitude 99% and pH=5), and decreased (6%) after treatments lasting longer than 5 min (Sourki et al., 2017). These differences caused by the US-pretreatment are probably due to changes in the structure of the polysaccharides that affect their water solubility and their tendency to interact with other cereal polymers (Zannini et al., 2022).\u003c/p\u003e\n\u003cp\u003eThe specific energy of ultrasonic cavitation damages the cell walls, which increases water penetration and leads to the release of polysaccharides (Sourki et al., 2017). This change is of physiological importance for\u0026nbsp;\u0026beta;-glucans, since their health promoting benefits depend on their extractability and solubility (EFSA, 2011). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe Mw of \u0026beta;-glucans was slightly lower for BB compared to OB (Table 3). It was reported to range from 1.18\u0026times;10\u003csup\u003e5\u003c/sup\u003e to 7.55\u0026times;10\u003csup\u003e5\u003c/sup\u003e g/mol in barley bran (Zheng et al., 2011) and from 1.19\u0026times;10\u003csup\u003e5\u003c/sup\u003e to 2.3\u0026times;10\u003csup\u003e5\u003c/sup\u003e g/mol in oat bran (\u0026Aring;man et al., 2004), which is somewhat lower compared to our results. These differences could derive from several factors, like cereal variety, extraction conditions and measurement method. The \u0026beta;-glucans Mw of OB and BB decreased after US-pretreatment by 7-21.7 %, respectively. The larger degradation of \u0026beta;-glucans in BB could be attributed to the higher specific energy input and longer treatment time (36 min) compared to treatment of OB (7 min). Benito-Rom\u0026aacute;n et al. (2013) recorded a decrease in the \u0026beta;-glucan Mw of barley flour between 13 % and 43 % along ultrasound specific energies from 109.5 kJ/kg to 1169.5 kJ/kg, whereby the decrease in Mw was positively correlated with an increase in the specific energy of the treatment. The \u0026beta;-glucan Mw degradation of 13 % after a 4.5 min US treatment of hull-less barley flour was found by Sourki et al. (2017). The 10 min of US treatment of mushroom \u0026beta;-glucan resulted in 58.6% lower Mw (Chen et al., 2015). In our previous study (Grgić et al., 2024a) we found a decrease (9%) in the \u0026beta;-glucan Mw of oat flour (from 3.71 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e g mol\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003eto 3.39 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e g mol\u003csup\u003e-1\u003c/sup\u003e)\u003csup\u003e\u0026nbsp;\u003c/sup\u003eand an increase (14%) in barley flour (from 3.30 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e g mol\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003eto 3.76 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e g mol\u003csup\u003e-1\u003c/sup\u003e) after PEF treatment, which can be explained by a less aggressive effect of this technology on the structural properties of \u0026beta;-glucans. The exposure of a material to a high shear force generated during ultrasonic cavitation results in a degradation of \u0026beta;-glucans, i.e. decrease in Mw (Benito-Rom\u0026aacute;n et al., 2013). Johansson et al. (2018) found that bread containing 30 % finely ground oat bran had a higher concentration of \u0026beta;-glucans with a lower Mw, but also had a cholesterol-lowering effect despite the lower Mw but due to the increased viscosity.\u003c/p\u003e\n\u003cp\u003eSoluble \u0026beta;-glucans made up 54.1% of the total \u0026beta;-glucans in the control OB while it was 35.5% in the control BB (Table 3). The obtained results are in agreement with Gajdo\u0026scaron;ov\u0026aacute; et al. (2007), who found that different varieties of oats contain 27-51% of soluble \u0026beta;-glucans, while for barley it is generally lower amounting to 18-39%. Lower solubility of barley \u0026beta;-glucans could be due to the high number of long cellotriosyl sequences (Mikkelsen et al., 2013).\u0026nbsp;Our results show that the content of soluble \u0026beta;-glucans after US-pretreatment was higher depending on the bran type (\u003cem\u003ep\u003c/em\u003e=0.009); it was 31% higher in OB and 40% higher in BB, compared to control. Chen et al. (2015) found an increase of 33.5% in water solubility of ultrasound (10 min, amplitude 50-60 %) treated \u0026beta;-glucan obtained from mushroom \u003cem\u003ePoria cocos\u003c/em\u003e. Furthermore, ultrasound treatment (850 kHz, 1.3 W cm\u003csup\u003e-2\u003c/sup\u003e, 20 min, 40 \u0026deg;C) increased the content of water-soluble dietary fiber in rice bran for 17.5% (Vaitkeviciene et al., 2022). The recorded changes in solubility were related to the \u0026beta;-glucans structure modified with ultrasonication treatment i.e., lower Mw (De Vuyst et al., 2017).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e Total content, solubility, and molecular weight (Mw) of \u0026beta;-glucans in control (C) and US-pretreated oat (OB) and barley (BB) bran\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"598\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.92617449664429%\"\u003e\n \u003cp\u003eSample\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003eOB-C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003eBB-C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003eOB-US\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003eBB-US\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.92617449664429%\"\u003e\n \u003cp\u003eTotal \u0026beta;-glucans (g/100 g d.w.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e7.45 \u0026plusmn; 0.27\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e4.54 \u0026plusmn; 0.02\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e8.37 \u0026plusmn; 0.34\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e5.06 \u0026plusmn; 0.12\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.92617449664429%\"\u003e\n \u003cp\u003eSoluble \u0026beta;-glucans (g/100 g d.w.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e4.03 \u0026plusmn; 0.02\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e1.61 \u0026plusmn; 0.06\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e6.47 \u0026plusmn; 0.11\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e3.81 \u0026plusmn; 0.18\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.92617449664429%\"\u003e\n \u003cp\u003eInsoluble \u0026beta;-glucans (g/100 g d.w.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e3.42 \u0026plusmn; 0.02\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e2.93 \u0026plusmn; 0.06\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e1.89 \u0026plusmn; 0.11\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e1.25 \u0026plusmn; 0.18\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"38.92617449664429%\"\u003e\n \u003cp\u003eAverage Mw (\u0026times;10\u003csup\u003e5\u003c/sup\u003e g mol\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e3.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e2.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e2.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.268456375838927%\"\u003e\n \u003cp\u003e2.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea\u0026ndash;d Values within the same row marked with different letters differ significantly according to Tukey\u0026rsquo;s test (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Fermentation kinetics and \u0026beta;-glucan content of oat and barley bran sourdough\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe pH changes during the 24 h of sourdough fermentation of OB and BB was well (p\u0026lt;0.001)\u0026nbsp;fitted to the Gompertz model (Fig. 4, Table 3). The both control samples had similar acidification rate, but the pH decline in 24 h was bigger for OB (Table 3, Fig. 4). The acidification rate of OB was similar to that previously observed for oat flour, yet slower than when the bran was mixed with flour (0.17 h\u003csup\u003e-1\u003c/sup\u003e) (Grgić et al., 2024b). On the contrary, BB had slower acidification rate that barley flour or its blend with bran (0.34-0.32 h\u003csup\u003e-1\u003c/sup\u003e) (Grgić et al., 2024b), probably due to a higher dough yield (water dilution) but also different starter used in this study. In this study, the interaction between bran type and US-pretreatment affected the pH drop (A) (\u003cem\u003ep\u003c/em\u003e=0.04), and the acidification rate (p\u0026lt;0.001) of sourdough fermentation. The US-pretreatment slightly reduced the acidification rate of BB which could be due to a lowering of \u0026alpha;-amylase activity (Grgić et al., 2024b).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The optimum sourdough pH value for bread making is approx. 4, which requires a fermentation of 6 to 24 h at a temperature of 25 \u0026deg;C to 35 \u0026deg;C (De Vuyst and Neysens, 2005). To achieve a stable pH of approx. 4, 18 h of sourdough fermentation was required for BB, while it was extended to 23 h after ultrasonication (Fig. 4). For both control and ultrasonicated OB, 14.5 h was sufficient to achieve a stable pH of 4 (Fig. 4). Although the LAB count was lower in barley sourdough than in oat sourdough, the number of viable LAB and yeast cells at the end of the fermentation, regardless of US-pretreatment (Table 4), was typical for the mature sourdough (De Vuyst et al., 2017).\u003c/p\u003e\n\u003cp\u003eThe TTA of OB sourdough was higher (51%) after US-pretreatment compared to its control and by 158-175 % compared to both barley samples (Table 4). Sahin et al. (2021) reported the TTA of 5.92 mL 0.1 M NaOH of oat bran sourdough fermented with LAB strain \u003cem\u003eLeuconostoc citreum\u003c/em\u003e TR116, at a dough yield of 250, for 48 h at 30\u0026deg;C. In our study, the TTA of the control OB sourdough was 65 % lower due to the much shorter fermentation time, but the US-pretreatment raised it to nearly the same value as observed in the long fermentation process described by Sahin et al. (2021). The addition of OB and BB to flour was shown to have a positive effect on the acidification kinetics of oat and barley flour, with increased (19%) TTA value of 7.00 for barley and 7.53 for oats, after 15 h of fermentation at 30 \u0026deg;C (Grgić et al., 2024b).\u003c/p\u003e\n\u003cp\u003eTotal \u0026beta;-glucans content in the control samples of OB and BB decreased by 28.7-33.9 %, whereas in the US-pretreated samples, the decrease was only 4.89-6.91 % compared to their levels before fermentation. Although the control BB exhibited lower \u0026beta;-glucanase activity compared to OB (9.1 MBG4 U/kg d.w. vs. 13.3 MBG4 U/kg d.w., respectively),\u0026nbsp;the bigger degradation of barley\u0026nbsp;\u0026beta;-glucans could be attributed to a longer fermentation time, since the conditions of sourdough fermentation are ideal for the \u0026beta;-glucanase activity. The lowering of \u0026beta;-glucanase activity of OB and BB (to 4.10 MBG4 U/kg d.w. or 5.86 MBG4 U/kg d.w., respectively) with US-pretreatment was reported in our previous research (Grgić et al., 2023).\u0026nbsp;Hence, the content of total\u0026nbsp;\u0026beta;-glucans was higher in sourdough from\u0026nbsp;US-pretreated samples compared to sourdough from untreated bran (by 47.5% in OB and 56.7% in BB sourdough), and even slightly higher compared to untreated bran before fermentation. Previously, it was reported that the sourdough fermentation of OB with rye sourdough had no effect on \u0026beta;-glucans content, but significantly reduced their Mw due to the endogenous \u0026beta;-glucanase activity of rye and oats (Degutyte-Fomins et al., 2002).\u0026nbsp;Lu et al. (2018)\u0026nbsp;found a slight decrease (4.2 - 4.9 %) in \u0026beta;-glucans content of oat sourdough, as OB was thermally pretreated to inactivate endogenous \u0026beta;-glucanase before fermentation. Similarly, microwave pretreatment of rice flour inactivated the endogenous \u0026beta;-glucanase of rice flour and preserved the content and Mw of \u0026beta;-glucans in the production of gluten-free bread (P\u0026eacute;rez-Quirce et al., 2017). Therefore, our US-pretreatment which partly inactivated \u0026beta;-glucanase was equally efficient as thermal or microwave treatment in preventing the degradation of \u0026beta;-glucans (Grgić et al., 2023).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e The parameters of acidification kinetics during 24 h of fermentation according to the Gompertz model, colony forming units (CFU) of LAB and yeast, pH value at the end of fermentation, total acidity (TTA), and total \u0026beta;-glucans content of sourdough\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"600\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eSample/ parameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003eOB-C-SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003eBB-C-SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003eOB-US-SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003eBB-US-SD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003e\u0026micro;\u003csub\u003emax\u003c/sub\u003e (h\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.10 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.11 \u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.13\u0026plusmn; 0.01\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.09 \u0026plusmn; 0.00\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eA (dpH)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e2.04 \u0026plusmn; 0.02\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.75 \u0026plusmn; 0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e2.23 \u0026plusmn; 0.03\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.77 \u0026plusmn; 0.01\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003e\u003cem\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.996\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.989\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.973\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e0.996\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eTime (h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e14.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e14.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eLAB (CFU/g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.63\u0026times;10\u003csup\u003e9\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.42\u0026times;10\u003csup\u003e8\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.23\u0026times;10\u003csup\u003e9\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e4.35\u0026times;10\u003csup\u003e8\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eYeast (CFU/g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.77 \u0026times; 10\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.54 \u0026times; 10\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e6.15 \u0026times; 10\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e1.75 \u0026times; 10\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003epH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.98 \u0026plusmn; 0.13\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.90 \u0026plusmn; 0.04\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.93 \u0026plusmn; 0.16\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.95 \u0026plusmn; 0.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003eTTA (mL 0.1 M NaOH)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.85 \u0026plusmn; 0.42\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e2.11 \u0026plusmn; 0.15\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e5.81 \u0026plusmn; 0.28\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e2.25 \u0026plusmn; 0.31\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.208681135225376%\"\u003e\n \u003cp\u003e\u0026beta;-glucans (g/100 g d.w.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e5.40 \u0026plusmn; 0.32\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e3.00 \u0026plusmn; 0.1\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e7.96 \u0026plusmn; 0.41\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.697829716193656%\"\u003e\n \u003cp\u003e4.71 \u0026plusmn; 0.1\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003ea\u0026ndash;d Values within the same row marked with different letters differ significantly according to Tukey\u0026rsquo;s test (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05)\u003c/p\u003e\n\u003cp\u003eOB \u0026ndash; oat bran; BB \u0026ndash; barley bran; C \u0026ndash; control; US \u0026ndash; ultrasound pretreated; SD \u0026ndash; sourdough.\u003c/p\u003e\n\u003cp\u003e\u0026micro;\u003csub\u003emax\u0026nbsp;\u003c/sub\u003e\u0026ndash; maximum acidification rate; A \u0026ndash; difference in pH (units)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003e3.5 \u0026nbsp;\u003cem\u003e\u0026beta;\u003c/em\u003e-glucans content and physical properties of flatbreads\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe partial replacement of semi-refined wheat flour (10 %, w/w) with OB or BB, or sourdough, significantly enriched flatbreads with\u003cem\u003e\u0026nbsp;\u0026beta;\u003c/em\u003e-d-glucans (Table 5). As expected, the enrichment was greater after adding OB than BB, as well as after US-pretreatment, but lower after sourdough fermentation. Hence, the largest enrichment was achieved by substitution of wheat flour with OB-US (182%) compared the use of sourdough from untreated BB (only 28%).\u0026nbsp;The increase in \u0026beta;-glucans content observed in bread mirrored the content observed in the raw material itself; the \u0026beta;-glucans content in bread was positively correlated (\u003cem\u003er\u003c/em\u003e=0.966, \u003cem\u003ep\u003c/em\u003e=0.03) with the \u0026beta;-glucans content in the sourdough.\u003c/p\u003e\n\u003cp\u003eThe addition of control or US-pretreated OB or BB did not significantly change the specific volume of flatbread compared to the control wheat bread (Table 5). The specific volume of composite breads was dependent on the bran type (\u003cem\u003ep\u003c/em\u003e=0.049) and sourdough addition (p\u0026lt;0.01). On average, it was higher for barley than for oat composite breads, and higher in breads with added sourdough. Similar results were obtained by Lee et al. (2020) in whose study wheat bread enriched with 5 or 10 % of wheat bran had a slightly higher specific volume, while a bran addition higher than 15% resulted in lower specific volume compared to control bread. In addition, Tiwari et al. (2013) found that the bread of acceptable quality can be produce with the substitution of wheat flour with 30% of OB, although there was a significant reduction in a specific volume. The bread specific volume is determined by the retention of gas which increases during the sourdough fermentation process due to increase in dietary fiber solubility, especially water-extractable AX (Verdonck et al., 2023). The favorable ratio of soluble to insoluble fiber in bran used in this study (40% in barley and 50 % in oat) (Grgić et al., 2023) might have helped in preserving the volume of bread with low amount of bran. This ratio was probably further improved after US (Du et al., 2019), and sourdough fermentation. US-enhanced solubility of fiber is evident from our results showing higher water-extractable AX content in oats (Table 2) and enhanced soluble \u0026beta;-glucans content of both bran types (Table 3). Our results are in line with several previous studies. Vela et al. (2023) showed that bread baked with US-pretreated rice flour had a significantly higher specific volume (14-25 %) than the control with untreated flour, probably due to the partial depolymerization of the starch, which leads to improved fermentation and higher production and retention of CO\u003csub\u003e2\u003c/sub\u003e (Vela et al., 2023). Further on,\u0026nbsp;the enhanced specific volume of sourdough-type bread containing bran compared to yeast control was reported (De Vuyst et al., 2017; Mart\u0026iacute;n-Garcia et al., 2021). Similarly, Pontonio et al. (2020) reported a 15-25 % increase in the specific volume of wheat bread with barley, wheat, or emmer bran sourdough.\u0026nbsp;In our study, the specific volume of breads containing sourdough-fermented untreated or US-pretreated BB was significantly (p\u0026lt;0.001) increased (12-23 %) even compared to the wheat control bread.\u003c/p\u003e\n\u003cp\u003eNevertheless, flatbreads with added bran (13-15 %) or sourdough (6-21 %) had a higher spread ratio than the control wheat flatbread. According to Banu et al. (2017) the addition of bran (10-30 %) to wheat flour resulted in a weaker dough and possibly of bread with a higher spread ratio. Spread ratio of our flatbreads was dependent on the interaction between the bran type, US-pretreatment, and sourdough fermentation (\u003cem\u003ep\u003c/em\u003e=0.02). The spread ratio was reduced after adding sourdough from control OB, but it increased after adding sourdough of US-pretreated bran of both types. In contrast, the addition of unfermented US-pretreated OB or BB significantly reduced bread spread ratio compared to bread with control bran (19%, 20%, respectively) and even compared to the wheat control (by 8-9 %, respectively).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere were no significant differences in redness between breads (\u003cem\u003ea\u003c/em\u003e* value between 0.5-1.5). As expected, bran addition slightly darkened bread color compared to the control wheat bread. The addition of OB resulted in a small TCD (\u0026lt;1.5), whereas the TCD of bread with BB was distinct (1.5 \u0026lt; TCD \u0026lt; 3) from the control wheat bread. The presence of various pigments in cereal bran, such as chlorophyll, carotene, and lutein, has the potential to darken the color of bread (Hu et al., 2022). The addition of OB or BB which was US-pretreated and/or sourdough fermented resulted in a very distinct TCD (\u0026gt; 3). It is important to notice that all sourdough breads were lighter but less yellow than the control, whereas flatbreads with OB-US or BB-US showed similar lightness \u003cem\u003eL\u003c/em\u003e* but 2-fold higher yellowness \u003cem\u003eb\u003c/em\u003e* compared to the wheat control flatbread. The differences in the color of the flatbread after adding sourdough could be due to a lower sugar content after fermentation, and the lower pH of the dough, which could have slowed down the polyphenol oxidase (PPO) activity and darkening of the dough (Habu\u0026scaron; et al., 2021). Brown pigments are formed due to the activity of PPO which catalyzes the oxidation of free and reduced phenolic compounds (Olaerts et al., 2018). PPO is mainly located in cereal bran (Grgić et al., 2024b) and its activity depends on pH value (Habu\u0026scaron; et al., 2021). Nevertheless, the bread color is formed in baking at high temperatures majorly depending on the Maillard reactions \u003cem\u003ei.e\u003c/em\u003e., reaction of amino acids and reducing sugars (Olaerts et al., 2018). Sourdough fermentation creates an acidic environment that reduces the availability of amino acids, while microbial activity reduces the sugar content, both limiting the Maillard reaction (Limbad et al., 2020). The US-pretreatment of bran further increased the TCD (approx. 13 %) of flatbread containing sourdough. These slightly higher \u003cem\u003eL\u003c/em\u003e* and TCD values after bran US-pretreatment could be due to a lower \u0026alpha;-amylase and/or PPO activity (Grgić et al., 2023, Habu\u0026scaron; et al., 2021).\u003c/p\u003e\n\u003cp\u003eCompared to the wheat control sample (FB-C), bread with added control BB or OB was harder (16-64 %) and chewier (28-46 %) (Fig. 5).\u0026nbsp;Tiwari et al. (2016) recorded an increase in bread hardness of 303-567 % after replacing 50% and 70% of wheat flour with oat bran. In our study, the US-pretreatment or sourdough fermentation had both improving effect on the bread texture.\u0026nbsp;The hardness and chewiness of composite flatbreads depended on the interaction between bran type and sourdough addition or US-pretreatment, as well as the interaction between sourdough fermentation and US-pretreatment (p\u0026lt;0.01). The cohesiveness was mainly influenced by the bran type (\u003cem\u003ep\u003c/em\u003e=0.03) and the interaction between sourdough and US-pretreatment (\u003cem\u003ep\u003c/em\u003e=0.02). It was higher for barley than oat-containing breads, or after employing US-pretreatment or sourdough fermentation but not if they were combined. After adding sourdough, the chewiness of both barley- and oat-containing flatbread was reduced by 51-57 %, while hardness was reduced (by 18%) only in oat flatbread, whereas the cohesiveness increased by 8-11 %, respectively (Fig. 5). The reduction of hardness or chewiness of oat flatbread was bigger in the case of US-pretreatment compared to sourdough fermentation. Unlike in barley composite bread, the beneficial impact of US-pretreatment prior to sourdough fermentation was evident in oat composite bread as demonstrated by a 27% reduced hardness and a 20% lower chewiness, compared to bread made with sourdough from untreated OB. Flatbread containing US-pretreated OB or BB showed lower hardness (17-48 %) and chewiness (52-66 %), while higher cohesiveness (16-18 %) even compared to the wheat control flatbread. This improvement could be attributed to the higher solubility of \u0026beta;-glucans (Table 3), as well as increased water swelling (42-48 %) and retention capacity (44-59 %) of OB and BB (respectively) which we reported previously (Grgić et al., 2023). According to Ma et al. (2022) pre-gelatinized starch can improve texture properties, by reducing the hardness and chewiness but increasing the cohesiveness of the bread, due to the higher water-retention capacity. \u003cem\u003ei.e\u003c/em\u003e., improved water content of the bread. Furtheron, the cavitation during the US-pretreatment combined with temperatures reaching 67 \u0026deg;C or 72 \u0026deg;C towards the end of the treatment, initiated the pre-gelatinization of starch. This aligns with the findings of Jalali et al. (2020), who reported that bread made with US-pregelatinized corn flour exhibited significantly reduced hardness.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Principal component analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe first two components of the PCA with eigenvalues of 3.598 and 2.800, accounting for 80% of the total variance, were considered (Fig. 6). The first component contrasts the variables spread ratio, bread hardness, and chewiness with crust \u003cem\u003eb*\u003c/em\u003e and cohesiveness (Fig. 6a). The second component contrasts variables specific volume, crust \u003cem\u003eL*\u003c/em\u003e color parameter and bread cohesiveness with chewiness. The first component contrasts flatbreads containing US-pretreated OB or BB from other bread samples, while the second component separates sourdough-containing breads from other samples (Fig. 6b). The flatbreads made with untreated bran were characterized by their hardness and chewiness, breads with US-pretreated bran were depicted in \u0026beta;-glucans content, while all sourdough-containing flatbreads were associated with a high specific volume, spread ratio and crust lightness.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe study explored the impact of ultrasound treatment of oat and barley bran regarding the content, molecular weight and water solubility of \u0026beta;-glucans, alongside the nutritive and technological properties of flatbread. While ultrasonication enhanced the acidification power of oat bran, it did not have the same effect on barley bran. Ultrasound pretreatment is a useful alternative to thermal pretreatment for preventing the degradation of \u0026beta;-glucans in sourdough fermentation and bread making since it inactivates endogenous \u0026beta;-glucanase. Compared to the control wheat bread, composite flatbreads with 10% of wheat flour replaced with ultrasonically pretreated and/or sourdough fermented oat or barley bran showed improvements in specific volume, color, and texture. Although the combined effects of ultrasound and sourdough fermentation on the examined nutritional and physical properties of the flatbread was not definitively proven, they could enhance consumer acceptance. Therefore, high-intensity ultrasound is a promising technique for functional modifications of oat and barley bran, applicable in bakery and products and other foods. Future studies should focus on the shelf-life and consumer acceptance of foods incorporating ultrasonicated bran.\u003c/p\u003e\n"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003eAll relevant data are shown in the manuscript. Additional data is available upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e The authors declare no conflict of interest. The manuscript has been read and approved for submission by all authors\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCode availability\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution\u0026nbsp;\u003c/strong\u003eTomislava Grgić: formal analysis, data curation, writing original draft, and preparation of all tables and figures; Roman Bleha: methodology, and formal analysis; Petra Smrčkov\u0026aacute;: formal analysis; Andry Synytsya: data curation, resources, writing original draft, review and editing, and revision of the manuscript; Bojana Voučko: experimental procedure, project administrator, revision of the manuscript; Nikolina Čukelj Mustač:\u0026nbsp;review and editing, and revision of the manuscript;\u0026nbsp;Marcela Slukov\u0026aacute;:\u0026nbsp;review and editing, and revision of the manuscript;\u0026nbsp;Dubravka Novotni: validation, revision of the manuscript, and supervision. All authors read the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003ePhD student Tomislava Grgić is thankful for a received mobility grant within the Central European Exchange Program (CEEPUS) at the University of Chemistry and Technology (UCT), Prague, Czech Republic. We thank Lesaffre Adriatic Inc. for donating LivendoTM LV4 starter.\u003c/p\u003e\n\n\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e This paper is supported by the PRIMA program under grant agreement No 2031 project \u0026ldquo;FLAT BREAD MINE\u0026rdquo;. This project is part of the PRIMA programme, which is an Art.185 initiative supported and funded under Horizon 2020, the European Union\u0026rsquo;s Framework Programme for Research and Innovation. Disclaimer: The results and content found on this Paper / Report reflects only the author\u0026rsquo;s view. The PRIMA Foundation is not responsible for any use that may be made of the information it contains.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003e\u003cstrong\u003e AACC \u0026ndash; American Association of Cereal Chemists. (2000). Method 10-05.01 Guidelines for measurement of volume by rapeseed displacement. Approved Methods of the American Association of Cereal Chemists International, 10th ed. Saint Paul, Minnesota, USA.\u003c/strong\u003e\u003c/li\u003e\n\u003cli\u003eAboshora, W., Lianfu, Z., Dahir, M., Qingran, M., Musa, A., Gasmalla, M. A. A., \u0026amp; Omar, K. A. (2016). Influence of doum (Hyphaene thebaica L.) flour addition on dough mixing properties, bread quality and antioxidant potential. \u003cem\u003eJournal of Food Science and Technology\u003c/em\u003e, \u003cem\u003e53\u003c/em\u003e(1), 591\u0026ndash;600. https://doi.org/10.1007/s13197-015-2063-1\u003c/li\u003e\n\u003cli\u003eAhmad, A., Anjum, F. M., Zahoor, T., Nawaz, H., Ahmed, Z. (2010). Extraction and characterization of \u0026beta;-d-glucan from oat for industrial utilization. \u003cem\u003eInternational journal of biological macromolecules, 46\u003c/em\u003e(3), 304-309.\u003c/li\u003e\n\u003cli\u003e\u0026Aring;man, P., Rimsten, L., \u0026amp; Andersson, R. (2004). Molecular weight distribution of \u0026beta;-Glucan in oat-based foods. \u003cem\u003eCereal Chemistry, 81\u003c/em\u003e(3), 356-360. https://doi.org/10.1094/CCHEM.2004.81.3.356\u003c/li\u003e\n\u003cli\u003eAOAC \u0026ndash; Association of Official Analytical Chemists. (2012). Official Method 995.16 \u0026beta;-D-glucan in barley and oats. Official Methods of analysis of AOAC International, 19th ed. Washington, DC\u003c/li\u003e\n\u003cli\u003eBai, Y. P., Zhou, H. M., Zhu, K. R., Li, Q. (2021). Effect of thermal processing on the molecular, structural, and antioxidant characteristics of highland barley \u0026beta;-glucan. Carbohydrate Polymers 271. https://doi.org/10.1016/j.carbpol.2021.118416.\u003c/li\u003e\n\u003cli\u003eBanu, I., Măcelaru, I., \u0026amp; Aprodu, I. (2017). Bioprocessing for improving the rheological properties of dough and quality of the wheat bread supplemented with oat bran. \u003cem\u003eJournal of Food Processing and Preservation\u003c/em\u003e, \u003cem\u003e41\u003c/em\u003e(5). https://doi.org/10.1111/jfpp.13112\u003c/li\u003e\n\u003cli\u003eBenito-Rom\u0026aacute;n, \u0026Oacute;., Alonso, E., \u0026amp; Cocero, M. J. (2013). Ultrasound-assisted extraction of \u0026beta;-glucans from barley. \u003cem\u003eLWT\u003c/em\u003e, \u003cem\u003e50\u003c/em\u003e(1), 57\u0026ndash;63. https://doi.org/10.1016/j.lwt.2012.07.006\u003c/li\u003e\n\u003cli\u003eBrubach, J. B., Mermet, A., Filabozzi, A., Gerschel, A., Roy, P. (2005). Signatures of the hydrogen bonding in the infrared bands of water. \u003cem\u003eThe Journal of chemical physics, 122\u003c/em\u003e(18).\u003c/li\u003e\n\u003cli\u003eChen, C., Wang, L., Wang, R., Luo, X., Li, Y., Li, J., Li, Y., \u0026amp; Chen, Z. (2018). Ultrasound-assisted extraction from defatted oat (Avena sativa L.) bran to simultaneously enhance phenolic compounds and \u0026beta;-glucan contents: Compositional and kinetic studies. \u003cem\u003eJournal of Food Engineering\u003c/em\u003e, \u003cem\u003e222\u003c/em\u003e, 1\u0026ndash;10. https://doi.org/10.1016/j.jfoodeng.2017.11.002\u003c/li\u003e\n\u003cli\u003eChen, J., Chen, L., Lin, S., Liu, C., \u0026amp; Cheung, P. C. K. (2015). Preparation and structural characterization of a partially depolymerized beta-glucan obtained from Poria cocos sclerotium by ultrasonic treatment. \u003cem\u003eFood Hydrocolloids\u003c/em\u003e, \u003cem\u003e46\u003c/em\u003e, 1\u0026ndash;9. https://doi.org/10.1016/j.foodhyd.2014.12.005\u003c/li\u003e\n\u003cli\u003eDanciu, C. A., Tulbure, A., Stanciu, M. A., Antonie, I., Capatana, C., Zerbeș, M. V., Giurea, R., \u0026amp; Rada, E. C. (2023). Overview of the sustainable valorization of using waste and by-products in grain processing. \u003cem\u003eFoods\u003c/em\u003e \u003cem\u003e12\u003c/em\u003e(20). https://doi.org/10.3390/foods12203770\u003c/li\u003e\n\u003cli\u003eDe Vuyst, L., \u0026amp; Neysens, P. (2005). The sourdough microflora: Biodiversity and metabolic interactions. \u003cem\u003eTrends in Food Science and Technology\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(1\u0026ndash;3), 43\u0026ndash;56. https://doi.org/10.1016/j.tifs.2004.02.012\u003c/li\u003e\n\u003cli\u003eDe Vuyst, L., Van Kerrebroeck, S., \u0026amp; Leroy, F. (2017). Microbial ecology and process technology of sourdough fermentation. \u003cem\u003eAdvances in Applied Microbiology\u003c/em\u003e, \u003cem\u003e100\u003c/em\u003e, 49\u0026ndash;160. https://doi.org/10.1016/bs.aambs.2017.02.003\u003c/li\u003e\n\u003cli\u003eDegutyte-Fomins, L., Sontag-Strohm, T., \u0026amp; Salovaara, H. (2002). Oat bran fermentation by rye sourdough\u003cem\u003e. Cereal Chemistry,\u003c/em\u003e \u003cem\u003e79\u003c/em\u003e(3), 345-348. https://doi.org/10.1094/CCHEM.2002.79.3.345\u003c/li\u003e\n\u003cli\u003eDu, B., Meenu, M., Liu, H., \u0026amp; Xu, B. (2019). A concise review on the molecular structure and function relationship of \u0026beta;-glucan. \u003cem\u003eInternational Journal of Molecular Sciences\u003c/em\u003e, \u003cem\u003e20\u003c/em\u003e(16). https://doi.org/10.3390/ijms20164032\u003c/li\u003e\n\u003cli\u003eEbrahimi, M., Ali Noori, S. M., Sadeghi, A., Coban, O., Zanganeh, J., Ghodsmofidi, S. M., Malvandi, Z., \u0026amp; Raeisi, M. (2022). Application of cereal-bran sourdough to enhance technological functionality of white wheat bread supplemented with pumpkin (\u003cem\u003eCucurbita pepo\u003c/em\u003e) puree. \u003cem\u003eLWT, 158\u003c/em\u003e. https://doi.org/10.1016/j.lwt.2022.113079\u003c/li\u003e\n\u003cli\u003eEFSA. (2011). Scientific Opinion on the substantiation of health claims related to beta-glucans from oats and barley and maintenance of normal blood LDL-cholesterol concentrations (ID 1236, 1299), increase in satiety leading to a reduction in energy intake (ID 851, 852), reduction of post-prandial glycaemic responses (ID 821, 824), and \u0026ldquo;digestive function\u0026rdquo; (ID 850) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. (2011). EFSA Journal, 9(6).\u003c/li\u003e\n\u003cli\u003eEstivi, L., Brandolini, A., Condezo-Hoyos, L., \u0026amp; Hidalgo, A. (2022). Impact of low-frequency ultrasound technology on physical, chemical and technological properties of cereals and pseudocereals. \u003cem\u003eUltrasonics Sonochemistry\u003c/em\u003e, \u003cem\u003e86.\u003c/em\u003e https://doi.org/10.1016/j.ultsonch.2022.106044\u003c/li\u003e\n\u003cli\u003eFan, D., Ma, W., Wang, L., Huang, J., Zhao, J., Zhang, H., Chen, W. (2012). Determination of structural changes in microwaved rice starch using Fourier transform infrared and Raman spectroscopy. \u003cem\u003eStarch‐St\u0026auml;rke, 64\u003c/em\u003e(8), 598-606. https://doi.org/10.1002/star.201100200\u003c/li\u003e\n\u003cli\u003eFan, S., Guo, D., Zhang, J., Yang, Y., Xue, H., Xue, T., \u0026amp; Bai, B. (2022). Structure, physicochemical properties, antioxidant, and hypoglycemic activities of water-soluble polysaccharides from millet bran. \u003cem\u003eJournal of Food Science, 87(\u003c/em\u003e12), 5263-5275. https://doi.org/10.1111/1750-3841.16362\u003c/li\u003e\n\u003cli\u003eFărcas, A. C., Socaci, S. A., Nemes, S. A., Pop, O. L., Coldea, T. E., Fogarasi, M., Biris-Dorhoi, E. S. (2022). An update regarding the bioactive compound of cereal by-products: Health benefits and potential applications. \u003cem\u003eFoods, 14\u003c/em\u003e(17). https://doi.org/10.3390/nu14173470\u003c/li\u003e\n\u003cli\u003eFlander, L., Suortti, T., Katina, K., \u0026amp; Poutanen, K. (2011). Effects of wheat sourdough process on the quality of mixed oat-wheat bread. \u003cem\u003eLWT\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e(3), 656\u0026ndash;664. https://doi.org/10.1016/j.lwt.2010.11.007\u003c/li\u003e\n\u003cli\u003eGajdo\u0026scaron;ov\u0026aacute;, A., Petrul\u0026aacute;kov\u0026aacute;, Z., Havrlentov\u0026aacute;, M., Červen\u0026aacute;, V., Hozov\u0026aacute;, B., \u0026Scaron;turd\u0026iacute;k, E., \u0026amp; Kogan, G. (2007). The content of water-soluble and water-insoluble \u0026beta;-d-glucans in selected oats and barley varieties. \u003cem\u003eCarbohydrate Polymers\u003c/em\u003e, \u003cem\u003e70\u003c/em\u003e(1), 46\u0026ndash;52. https://doi.org/10.1016/j.carbpol.2007.03.001\u003c/li\u003e\n\u003cli\u003eGamel, T.H., Abdel-Aal, E.S.M., Tosh, S.M. (2015). Effect of yeast-fermented and sour-dough making processes on physicochemical characteristics of \u0026beta;-glucan in whole wheat/oat bread. \u003cem\u003eLWT, 60\u003c/em\u003e(1), 78\u0026ndash;85. https://doi.org/10.1016/j.lwt.2014.07.030\u003c/li\u003e\n\u003cli\u003eGholizadeh, H., Naserian, A. A., Yari, M., Jonker, A., Yu, P. (2021). Crude protein fractionation, in situ ruminal degradability and FTIR protein molecular structures of different cultivars within barley, corn and sorghum cereal grains. \u003cem\u003eAnimal Feed Science and Technology, 275\u003c/em\u003e, 114855.\u003c/li\u003e\n\u003cli\u003eGrgić, T., Bleha, R., Smrkov\u0026aacute;, P., Stulić, V., Vuku\u0026scaron;ić Pavičić, T., Synytsya, A., Iveković, D., Novotni, D. (2024a). Pulsed electric field treatment of oat and barley flour: Influence on enzymes, non-starch polysaccharides, dough rheological properties and application in flat bread. \u003cem\u003eFood and Bioprocess Technology\u003c/em\u003e\u003c/li\u003e\n\u003cli\u003eGrgić, T., Drakula, S., Voučko, B., Čukelj Mustač, N., \u0026amp; Novotni, D. (2024b). Sourdough fermentation of oat and barley flour with bran and its application in flatbread made with no-time and dough retardation methods. \u003cem\u003eFermentation\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(3), 174. https://doi.org/10.3390/fermentation10030174\u003c/li\u003e\n\u003cli\u003eGrgić, T., Pavi\u0026scaron;ić, Z., Maltar-Strmečki, N., Voučko, B., Čukelj Mustač, N., Ćurić, D., Le-Bail, A., \u0026amp; Novotni, D. (2023). Ultrasound-assisted modification of enzymatic and antioxidant activities, functional and rheological properties of oat and barley bran. \u003cem\u003eFood and Bioprocess Technology\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(11), 2416\u0026ndash;2429. https://doi.org/10.1007/s11947-023-03074-5\u003c/li\u003e\n\u003cli\u003eHabu\u0026scaron;, M., Novotni, D., Gregov, M., \u0026Scaron;tifter, S., Čukelj Mustač, N., Voučko, B., \u0026amp; Ćurić, D. (2021). Influence of particle size reduction and high-intensity ultrasound on polyphenol oxidase, phenolics, and technological properties of wheat bran. \u003cem\u003eJournal of Food Processing and Preservation\u003c/em\u003e, \u003cem\u003e45\u003c/em\u003e(3). https://doi.org/10.1111/jfpp.15204\u003c/li\u003e\n\u003cli\u003eHarland, J. (2015). Authorised EU health claims for oat and barley grain fibre. In Sadler, M. J. (Ed.), \u003cem\u003eFoods, Nutrients and Food Ingredients with Authorised EU Health Claims \u003c/em\u003e(pp. 97\u0026ndash;108). Elsevier. https://doi.org/10.1016/B978-1-78242-382-9.00005-0\u003c/li\u003e\n\u003cli\u003eHong, T., Yin, J. Y., Nie, S. P., Xie, M. Y. (2021). Applications of infrared spectroscopy in polysaccharide structural analysis: Progress, challenge and perspective. \u003cem\u003eFood chemistry, 12\u003c/em\u003e. https://doi.org/10.1016/j.fochx.2021.100168 https:// doi. org/ 10. 2903/j. efsa. 2011. 2207\u003c/li\u003e\n\u003cli\u003eHu, H., Lin, H., Xiao, L., Guo, M., Yan, X., Su, X., Liu, L., \u0026amp; Sang, S. (2022). Impact of native form oat \u0026beta;-Glucan on the physical and starch digestive properties of whole oat bread. \u003cem\u003eFoods\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(17). https://doi.org/10.3390/foods11172622\u003c/li\u003e\n\u003cli\u003eJalali, M., Sheikholeslami, Z., Elhamirad, A. H., Haddad Khodaparast, M. H., \u0026amp; Karimi, M. (2020). The effect of the ultrasound process and pre-gelatinization of the corn flour on the textural, visual, and sensory properties in gluten-free pan bread. \u003cem\u003eJournal of Food Science and Technology\u003c/em\u003e, \u003cem\u003e57\u003c/em\u003e(3), 993\u0026ndash;1002. https://doi.org/10.1007/s13197-019-04132-7\u003c/li\u003e\n\u003cli\u003eJohansson, D. P., Andersson, R., Alminger, M., Landberg, R., \u0026amp; Langton, M. (2018). Larger particle size of oat bran inhibits degradation and lowers extractability of \u0026beta;-glucan in sourdough bread \u0026ndash; Potential implications for cholesterol-lowering properties in vivo. \u003cem\u003eFood Hydrocolloids\u003c/em\u003e, \u003cem\u003e77\u003c/em\u003e, 49\u0026ndash;56. https://doi.org/10.1016/j.foodhyd.2017.09.016\u003c/li\u003e\n\u003cli\u003eKatina, K., Salmenkallio-Marttila, M., Partanen, R., Forssell, P., \u0026amp; Autio, K. (2006). Effects of sourdough and enzymes on staling of high-fibre wheat bread. \u003cem\u003eLWT\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(5), 479\u0026ndash;491. https://doi.org/10.1016/j.lwt.2005.03.013\u003c/li\u003e\n\u003cli\u003eKaur, A., Singh, B., Yadav, M. P., Bhinder, S., \u0026amp; Singh, N. (2021). Isolation of arabinoxylan and cellulose-rich arabinoxylan from wheat bran of different varieties and their functionalities. Food Hydrocolloids, 112, 106287.\u003c/li\u003e\n\u003cli\u003eLazaridou, A., Biliaderis, C. G., Izydorczyk, M. S. (2007). Cereal \u0026Beta;-glucans: Structures, physical properties and physiological functions. In Biliaderis, C. G., Izydorczyk, M. S. (Eds.), \u003cem\u003eFunctional food carbohydrates\u003c/em\u003e, CRC Press. https://doi.org/10.1201/9781420003512\u003c/li\u003e\n\u003cli\u003eLazaridou, A., Marinopoulou, A., Matsoukas, N. P., \u0026amp; Biliaderis, C. G. (2014). Impact of flour particle size and autoclaving on \u0026beta;-glucan physicochemical properties and starch digestibility of barley rusks as assessed by in vitro assays. \u003cem\u003eBioactive Carbohydrates and Dietary Fibre\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(1), 58\u0026ndash;73. https://doi.org/10.1016/j.bcdf.2014.06.009\u003c/li\u003e\n\u003cli\u003eLee, D., Kim, M. J., Kwak, H. S., \u0026amp; Kim, S. S. (2020). Characteristics of bread made of various substitution ratios of bran pulverized by hammer mill or jet mill. \u003cem\u003eFoods\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(1). https://doi.org/10.3390/foods9010048\u003c/li\u003e\n\u003cli\u003eLimbad, M., Maddox, N. G., Hamid, N., \u0026amp; Kantono, K. (2020). Sensory and physicochemical characterization of sourdough bread prepared with a coconut water kefir starter. \u003cem\u003eFoods\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(9). https://doi.org/10.3390/foods9091165\u003c/li\u003e\n\u003cli\u003eLimberger-Bayer, V. M., de Francisco, A., Chan, A., Oro, T., Ogliari, P. J., \u0026amp; Barreto, P. L. (2014). Barley \u0026beta;-glucans extraction and partial characterization. \u003cem\u003eFood chemistry, 154\u003c/em\u003e, 84-89.\u003c/li\u003e\n\u003cli\u003eLu, J., Shan, L., Xie, Y., Min, F., Gao, J., Guo, L., Ren, C., Yuan, J., Gilissen, L., \u0026amp; Chen, H. (2019). Effect of fermentation on content, molecule weight distribution and viscosity of \u0026beta;-glucans in oat sourdough. \u003cem\u003eInternational Journal of Food Science and Technology\u003c/em\u003e, \u003cem\u003e54\u003c/em\u003e(1), 62\u0026ndash;67. https://doi.org/10.1111/ijfs.13902\u003c/li\u003e\n\u003cli\u003eLu, J., Shan, L., Xie, Y., Min, F., Gao, J., Guo, L., Ren, C., Yuan, J., Gilissen, L., \u0026amp; Chen, H., (2018). Effect of fermentation on content, molecular weight distribution and viscosity of \u0026beta;-glucans in oat sourdough. \u003cem\u003eInternational Journal of Food Science and Technology, 54\u003c/em\u003e(1), 62-67. https://doi.org/10.1111/ijfs.13902\u003c/li\u003e\n\u003cli\u003eLuo, D., Wu, R., Zhang, J., Zhang, K., Xu, B., Li, P., Yuan, Y., \u0026amp; Li, X. (2018). Effects of ultrasound assisted dough fermentation on the quality of steamed bread. \u003cem\u003eJournal of Cereal Science\u003c/em\u003e, \u003cem\u003e83\u003c/em\u003e, 147\u0026ndash;152. https://doi.org/10.1016/j.jcs.2018.07.016\u003c/li\u003e\n\u003cli\u003eMa, H., Liu, M., Liang, Y., Zheng, X., Sun, L., Dang, W., Li, J., Li, L., \u0026amp; Liu, C. (2022). Research progress on properties of pre-gelatinized starch and its application in wheat flour products. \u003cem\u003eGrain and Oil Science and Technology\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(2), 87\u0026ndash;97. https://doi.org/10.1016/j.gaost.2022.01.001\u003c/li\u003e\n\u003cli\u003eMart\u0026iacute;n-Garcia, A., Riu-Aumatell, M., \u0026amp; L\u0026oacute;pez-Tamames, E. (2023). Influence of process parameters on sourdough microbiota, physical properties and sensory profile. \u003cem\u003eFood Reviews International\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(1), 334\u0026ndash;348. https://doi.org/10.1080/87559129.2021.1906698\u003c/li\u003e\n\u003cli\u003eMikkelsen, M. S., Jespersen, B. M., Larsen, F. H., Blennow, A., \u0026amp; Engelsen, S. B. (2013). Molecular structure of large-scale extracted \u0026beta;-glucan from barley and oat: Identification of a significantly changed block structure in a high \u0026beta;-glucan barley mutant. \u003cem\u003eFood Chemistry\u003c/em\u003e, \u003cem\u003e136\u003c/em\u003e(1), 130\u0026ndash;138. https://doi.org/10.1016/j.foodchem.2012.07.097\u003c/li\u003e\n\u003cli\u003eMikkelsen, M. S., Jespersen, B. M., M\u0026oslash;ller, B. L., L\u0026aelig;rke, H. N., Larsen, F. H., \u0026amp; Engelsen, S. B. (2010). Comparative spectroscopic and rheological studies on crude and purified soluble barley and oat \u0026beta;-glucan preparations. \u003cem\u003eFood Research International, 43\u003c/em\u003e(10), 2417-2424.\u003c/li\u003e\n\u003cli\u003eOlaerts, H., Vandekerckhove, L., \u0026amp; Courtin, C. M. (2018). A closer look at the bread making process and the quality of bread as a function of the degree of preharvest sprouting of wheat (Triticum aestivum). \u003cem\u003eJournal of Cereal Science\u003c/em\u003e, \u003cem\u003e80\u003c/em\u003e, 188\u0026ndash;197. https://doi.org/10.1016/j.jcs.2018.03.004\u003c/li\u003e\n\u003cli\u003e\u0026Ouml;zkaya, B., Baumgartner, B., \u0026amp; \u0026Ouml;zkaya, H. (2018). Effects of concentrated and dephytinized wheat bran and rice bran addition on bread properties. \u003cem\u003eJournal of Texture Studies\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(1), 84\u0026ndash;93. https://doi.org/10.1111/jtxs.12286\u003c/li\u003e\n\u003cli\u003ePassos, C. P., \u0026amp; Coimbra, M. A. (2013). Microwave superheated water extraction of polysaccharides from spent coffee grounds. \u003cem\u003eCarbohydrate Polymers\u003c/em\u003e, \u003cem\u003e94\u003c/em\u003e(1), 626\u0026ndash;633. https://doi.org/10.1016/j.carbpol.2013.01.088\u003c/li\u003e\n\u003cli\u003eP\u0026eacute;rez-Quirce, S., Ronda, F., Lazaridou, A., \u0026amp; Biliaderis, C. G. (2017). Effect of microwave radiation pretreatment of rice flour on gluten-free breadmaking and molecular size of \u0026beta;-Glucans in the fortified breads. \u003cem\u003eFood and Bioprocess Technology\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(8), 1412\u0026ndash;1421. https://doi.org/10.1007/s11947-017-1910-7\u003c/li\u003e\n\u003cli\u003ePontonio, E., Dingeo, C., Di Cagno, R., Blandino, M., Gobbetti, M., \u0026amp; Rizzello, C. G. (2020). Brans from hull-less barley, emmer and pigmented wheat varieties: From by-products to bread nutritional improvers using selected lactic acid bacteria and xylanase. \u003cem\u003eInternational Journal of Food Microbiology\u003c/em\u003e, \u003cem\u003e313\u003c/em\u003e. https://doi.org/10.1016/j.ijfoodmicro.2019.108384\u003c/li\u003e\n\u003cli\u003eReidzane, S., Gramatina, I., Galoburda, R., Komasilovs, V., Zacepins, A., Bljahhina, A., Kince, T., Traksmaa, A., \u0026amp; Klava, D. (2023). Composition of polysaccharides in hull-less barley sourdough bread and their impact on physical properties of bread. \u003cem\u003eFoods\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(1). https://doi.org/10.3390/foods12010155\u003c/li\u003e\n\u003cli\u003eRieder, A., Ballance, S., L\u0026oslash;vaas, A., \u0026amp; Knutsen, S. H. (2015). Minimizing molecular weight reduction of \u0026beta;-glucan during barley bread making. \u003cem\u003eLWT\u003c/em\u003e, \u003cem\u003e64\u003c/em\u003e(2), 767\u0026ndash;774. https://doi.org/10.1016/j.lwt.2015.06.034\u003c/li\u003e\n\u003cli\u003eRieder, A., Holtekj\u0026oslash;len, A. K., Sahlstr\u0026oslash;m, S., \u0026amp; Moldestad, A. (2012). Effect of barley and oat flour types and sourdoughs on dough rheology and bread quality of composite wheat bread. \u003cem\u003eJournal of Cereal Science\u003c/em\u003e, \u003cem\u003e55\u003c/em\u003e(1), 44\u0026ndash;52. https://doi.org/10.1016/j.jcs.2011.10.003\u003c/li\u003e\n\u003cli\u003eRobert, P., Marquis, M., Barron, C., Guillon, F., Saulnier, L. (2005). FT-IR investigation of cell wall polysaccharides from cereal grains. Arabinoxylan infrared assignment. \u003cem\u003eJournal of Agricultural and Food Chemistry, 53\u003c/em\u003e(18), 7014-7018.\u003c/li\u003e\n\u003cli\u003eRosicka-Kaczmarek, J., Komisarczyk, A., Nebesny, E., \u0026amp; Makowski, B. (2016). The influence of arabinoxylans on the quality of grain industry products. \u003cem\u003eEuropean Food Research and Technology,\u003c/em\u003e \u003cem\u003e242\u003c/em\u003e(3), 295\u0026ndash;303. https://doi.org/10.1007/s00217-015-2549-0\u003c/li\u003e\n\u003cli\u003eSahin, A. W., Coffey, A., \u0026amp; Zannini, E. (2021). Functionalisation of wheat and oat bran using single-strain fermentation and its impact on techno-functional and nutritional properties of biscuits. \u003cem\u003eEuropean Food Research and Technology\u003c/em\u003e, \u003cem\u003e247\u003c/em\u003e(7), 1825\u0026ndash;1837. https://doi.org/10.1007/s00217-021-03755-5\u003c/li\u003e\n\u003cli\u003eSaka, M., \u0026Ouml;zkaya, B., Saka, I. (2021). The effect of bread-making methods on functional and quality characteristics of oat bran blended bread. \u003cem\u003eInternational Journal of Gastronomy and Food Science, 26\u003c/em\u003e. https://doi.org/10.1016/j.ijgfs.2021.100439\u003c/li\u003e\n\u003cli\u003eSourki, A. H., Koocheki, A., \u0026amp; Elahi, M. (2017). Ultrasound-assisted extraction of \u0026beta;-D-glucan from hull-less barley: Assessment of physicochemical and functional properties. \u003cem\u003eInternational Journal of Biological Macromolecules\u003c/em\u003e, \u003cem\u003e95\u003c/em\u003e, 462\u0026ndash;475. https://doi.org/10.1016/j.ijbiomac.2016.10.111\u003c/li\u003e\n\u003cli\u003eTiwari, U. P., Singh, A. K., \u0026amp; Jha, R. (2019). Fermentation characteristics of resistant starch, arabinoxylan, and \u0026beta;-glucan and their effects on the gut microbial ecology of pigs: A review. \u003cem\u003eAnimal Nutrition,\u003c/em\u003e \u003cem\u003e5\u003c/em\u003e(3), 217\u0026ndash;226). https://doi.org/10.1016/j.aninu.2019.04.003\u003c/li\u003e\n\u003cli\u003eTiwari, U., Cummins, E., Brunton, N., O\u0026rsquo;Donnell, C., \u0026amp; Gallagher, E. (2013). A comparison of oat flour and oat bran-based bread formulations. \u003cem\u003eBritish Food Journal\u003c/em\u003e, \u003cem\u003e115\u003c/em\u003e(2), 300\u0026ndash;313. https://doi.org/10.1108/00070701311302258\u003c/li\u003e\n\u003cli\u003eTosh, S. M., Ahmadi, L., Yip, L., Roudsari, M., \u0026amp; Wood, P. J. (2012). Presence of \u0026beta;-glucanase activity in wheat and dairy ingredients and use of organic salts as potential enzyme inhibitors. \u003cem\u003eJournal of Cereal Science\u003c/em\u003e, \u003cem\u003e56\u003c/em\u003e(3), 538\u0026ndash;543. https://doi.org/10.1016/j.jcs.2012.08.013\u003c/li\u003e\n\u003cli\u003eVaitkeviciene, R., Zadeike, D., Gaizauskaite, Z., Valentaviciute, K., Marksa, M., Mazdzieriene, R., Bartkiene, E., Lele, V., Juodeikiene, G., \u0026amp; Jakstas, V. (2022). Functionalisation of rice bran assisted by ultrasonication and fermentation for the production of rice bran\u0026ndash;lingonberry pulp-based probiotic nutraceutical. \u003cem\u003eInternational Journal of Food Science and Technology\u003c/em\u003e, \u003cem\u003e57\u003c/em\u003e(3), 1462\u0026ndash;1472. https://doi.org/10.1111/ijfs.15053\u003c/li\u003e\n\u003cli\u003eVasanthan, T., Gaosong, J., Yeung, J., \u0026amp; Li, J. (2002). Dietary fiber profile of barley flour as affected by extrusion cooking. \u003cem\u003eFood Chemistry, 77\u003c/em\u003e(1)\u003cem\u003e, \u003c/em\u003e35-40. https://doi.org/10.1016/S0308-8146(01)00318-1\u003c/li\u003e\n\u003cli\u003eVela, A. J., Villanueva, M., \u0026amp; Ronda, F. (2023). Physical modification caused by acoustic cavitation improves rice flour bread-making performance. \u003cem\u003eLWT\u003c/em\u003e, \u003cem\u003e183\u003c/em\u003e. https://doi.org/10.1016/j.lwt.2023.114950\u003c/li\u003e\n\u003cli\u003eVerdonck, C., De Bondt, Y., Pradal, I., Bautil, A., Langenaeken, N. A., Brijs, K., Goos, P., De Vuyst, L., \u0026amp; Courtin, C. M. (2023). Impact of process parameters on the specific volume of wholemeal wheat bread made using sourdough- and baker\u0026rsquo;s yeast-based leavening strategies. \u003cem\u003eInternational Journal of Food Microbiology\u003c/em\u003e, \u003cem\u003e396\u003c/em\u003e. https://doi.org/10.1016/j.ijfoodmicro.2023.110193\u003c/li\u003e\n\u003cli\u003eWei, C., Ge,Y., Liu, D., Zhao, S., Wei, M., Jiliu, J., Hu, X., Quan, Z., Wu, Y., Su, Y., Wang, Y., \u0026amp; Cao, L. (2022). Effects of high-temperature, high-pressure, and ultrasoinic treatment on the physicochemical properties and sturcture of soluble dietary fibers of millet bran. \u003cem\u003eFrontiers in Nutrition, 8.\u003c/em\u003e https://doi.org/10.3389/fnut.2021.820715\u003c/li\u003e\n\u003cli\u003eWolever, T. M. S., Tosh, S. M., Gibbs, A. L., Brand-Miller, J., Duncan, A. M., Hart, V., Lamarche, B., Thomson, B. A., Duss, R., \u0026amp; Wood, P. J. (2010). Physicochemical properties of oat \u0026beta;-glucan influence its ability to reduce serum LDL cholesterol in humans: A randomized clinical trial. \u003cem\u003eAmerican Journal of Clinical Nutrition\u003c/em\u003e, \u003cem\u003e92\u003c/em\u003e(4), 723\u0026ndash;732. https://doi.org/10.3945/ajcn.2010.29174\u003c/li\u003e\n\u003cli\u003eZambrano, J. A., Thyagarajan, A., Sardari, R. R. R., \u0026amp; Olsson, O. (2023). Characterization of high arabinoxylan oat lines identified from a mutagenized oat population. \u003cem\u003eFood Chemistry\u003c/em\u003e, \u003cem\u003e404\u003c/em\u003e. https://doi.org/10.1016/j.foodchem.2022.134687\u003c/li\u003e\n\u003cli\u003eZhang, M., Suo, W., Deng, Y., Jiang, L., Qi, M., Liu, Y., Li, L., Wang, C., Zheng, H., \u0026amp; Li, H. (2022). Effect of ultrasound-assisted dough fermentation on the quality of dough and steamed bread with 50% sweet potato pulp. \u003cem\u003eUltrasonics Sonochemistry\u003c/em\u003e, \u003cem\u003e82\u003c/em\u003e. https://doi.org/10.1016/j.ultsonch.2022.105912\u003c/li\u003e\n\u003cli\u003eZheng, X., Li, L., \u0026amp; Wang, Q. (2011). Distribution and molecular characterization of \u0026beta;-glucans from hull-less barley bran, shorts and flour. \u003cem\u003eInternational Journal of Molecular Sciences\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(3), 1563\u0026ndash;1574. https://doi.org/10.3390/ijms12031563\u003c/li\u003e\n\u003cli\u003eZwietering,\u003cem\u003e \u003c/em\u003eM.H.,\u003cem\u003e \u003c/em\u003eJongenburger,\u003cem\u003e \u003c/em\u003eI.,\u003cem\u003e \u003c/em\u003eRombouts,\u003cem\u003e \u003c/em\u003eF.M.,\u003cem\u003e \u003c/em\u003eVan,\u003cem\u003e \u003c/em\u003eK.,\u003cem\u003e \u003c/em\u003eRiet,\u003cem\u003e \u003c/em\u003eT.\u003cem\u003e \u003c/em\u003eModeling\u003cem\u003e \u003c/em\u003eof\u003cem\u003e \u003c/em\u003ethe\u003cem\u003e \u003c/em\u003eBacterial\u003cem\u003e \u003c/em\u003eGrowth\u003cem\u003e \u003c/em\u003eCurve. (1990).\u003cem\u003e Applied and Environmental Microbiology, 56\u003c/em\u003e,\u003cem\u003e \u003c/em\u003e1875\u0026ndash;1881. https://doi.org/10.1128/aem.56.6.1875-1881.1990\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 5","content":"\u003cp\u003eTable 5 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"food-and-bioprocess-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Food and Bioprocess Technology](https://www.springer.com/journal/11947)","snPcode":"11947","submissionUrl":"https://submission.nature.com/new-submission/11947/3","title":"Food and Bioprocess Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"acidification kinetics, arabinoxylan, β-glucanase activity, bread quality, FTIR, non-starch polysaccharides","lastPublishedDoi":"10.21203/rs.3.rs-4280152/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4280152/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Sourdough fermentation of bran can overcome the technological problems encountered in bread making but favors the activity of endogenous β-glucanase leading to a degradation of β-glucans. This study investigated the effects of high-intensity ultrasound (US) pretreatment of oat (OB) and barley (BB) bran on its β-glucans content, properties, and preservation in processing, as well as the on the acidification kinetics of bran sourdough fermentation and on its application in flatbread. To reduce β-glucanase activity, OB and BB (15 % water suspensions) were US-pretreated prior to sourdough fermentation. The acidification kinetics, the microbial viable cell count, and the total titratable acidity (TTA) of the sourdough were determined. The total β-glucans content of bran, sourdough, and bread, as well as water solubility and the molecular weight (Mw) of control and US-pretreated bran were investigated. The physical properties of control wheat and composite flatbreads were compared. The US-pretreatment increased the acidification rate (30%) and TTA (51%) of OB sourdough, however decreased the acidification rate of BB (18%). After the US-pretreatment of OB and BB, the total (11.5-12.3 %) and water-soluble β-glucans (31-40 %) increased while their Mw decreased (7-21.7 %). In sourdough and flatbread prepared with US-pretreated OB/BB, 93-95 % and 90-98 % of β-glucans were retained, respectively, compared to 64-72 % and 82-92 % in control samples. The US-pretreatment and/or sourdough fermentation of OB and BB resulted in flatbreads of higher specific volume (8-22 %) and cohesiveness (11-20%) while reduced hardness (40-55 %) and chewiness (51-73 %) compared to their control bread.","manuscriptTitle":"Ultrasound pretreatment of oat and barley bran contributes to the β-glucans content and technological properties of flatbread with or without sourdough","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-22 07:42:47","doi":"10.21203/rs.3.rs-4280152/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-06-05T00:39:08+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-25T22:58:50+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-21T12:15:53+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-05-08T06:22:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"e7df170b-552c-4498-8fbb-50587ac4ffde","date":"2024-04-29T06:26:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"f90fd346-fbaa-43c9-8b9b-2a547c79369f","date":"2024-04-25T10:25:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9cb0efe6-edee-45e7-8945-63ede7ad308f","date":"2024-04-23T04:09:33+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-04-23T00:36:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-18T08:38:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-18T03:52:20+00:00","index":"","fulltext":""},{"type":"submitted","content":"Food and Bioprocess Technology","date":"2024-04-17T07:39:23+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"food-and-bioprocess-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Food and Bioprocess Technology](https://www.springer.com/journal/11947)","snPcode":"11947","submissionUrl":"https://submission.nature.com/new-submission/11947/3","title":"Food and Bioprocess Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"84d9c3fc-2994-4bec-bb8d-45e781e33f08","owner":[],"postedDate":"April 22nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-06-25T11:54:06+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-22 07:42:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4280152","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4280152","identity":"rs-4280152","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}