Physico-Chemical Tailoring of Finger Millet Starch for Improved Barrier and Mechanical Performance

Physico-Chemical Tailoring of Finger Millet Starch for Improved Barrier and Mechanical Performance | 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 Physico-Chemical Tailoring of Finger Millet Starch for Improved Barrier and Mechanical Performance Naina Gautam, Shweta Rawat, Raj Kumar, Shashikant Yadav This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8660714/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Finger millet starch (NFS) was modified with a novel integrated citric acid (CA) (3, 5, and 8% w/w of total dry starch) and dry heat treatment (DHT) at 130 ºC for 5 h. Thin films were prepared from NFS, and modified starch (MFS) was prepared using a solvent casting method. The functional, thermal, and structural properties of thin films were comprehensively analysed. The thin films made with NFS exhibit a water vapour barrier of 3.81 ± 0.05 g s⁻¹ m⁻¹ Pa⁻¹, which is significantly higher than the water vapour barrier of 1.65 ± 0.43 g s⁻¹ m⁻¹ Pa⁻¹ of the thin films with MFS. Similarly, the tensile strength of the thin film made with NFS is 9.24 ± 0.514 MPa, while that of the thin film made with MFS is 29.82 ± 0.229 MPa. FTIR confirms the esterification in the starch matrix at 1730 cm − 1 . A smoother and more compact surface network was observed in thin films made with MFS than in NFS-based thin films. These observations suggest that the synergistic application of physical and chemical modification techniques significantly alters the functional properties of starch, thereby enhancing its suitability for food packaging applications. finger millet starch physical & chemical modification mechanical property barrier property biodegradability Figures Figure 1 Figure 2 Figure 3 Figure 4 Highlights Film morphology becomes smoother, denser, and more uniform. Mechanical strength and barrier performance are greatly enhanced. Relative crystallinity is markedly influenced by CA/DHT treatment. CA/DHT modification improves thermal stability and biodegradability. Introduction Plastics have become integral parts of households due to their multiple uses and affordable cost; however, their non-biodegradability poses a serious threat to both humans and the environment. As a result, accumulation in ecology is continuously increasing due to improper management of recycling and disposal [ 1 ]. Among all plastics, the food packaging sector generates approximately 40% of plastic waste [ 2 , 3 ]. Hence, biodegradable materials derived from renewable resources can serve as an alternative to synthetic plastics. Bioplastic-derived plant sources have gained popularity due to their lower maintenance requirements compared to animal or microbial sources [ 4 , 5 ]. Among natural polymers, cellulose is the simplest and most abundant on Earth. Many derivatives have been developed through chemical and physical processes to enhance their utility. Among derivatives, biodegradable cellulose acetate showed excellent impact resistance, mechanical properties, and moldability [ 6 ]. However, they are challenging to process, which limits their use as bioplastics. Abundance in nature, low cost, and thermoplastic behavior make starch a strong candidate for the synthesis of bioplastics. Amylose and amylopectin are the two main polymers of starch, in which amylose is linear, whereas amylopectin is a branched polymer [ 7 ]. Starch obtained from finger millet (Eleusine coracana) is cultivated in Asian and African countries. It is widely utilized for the preparation of drinks, cuisines, soups, sauces, ice cream, non-alcoholic beverages, porridge, ready-to-eat meals, confectionery, bakery goods, beer, and non-fermented foods due to its high nutritional value (carbohydrate (60–70%), fat (1.5–5%), protein (6.9%–19.9%), fiber (12.9%–20.0%, & minerals (2.4% and 4.0%) [ 8 ]. Despite millet’s good nutritional and functional attributes, significant amounts of starch were found in its granules, which can serve as a low-cost raw material for the development of bioplastics [ 9 ]. Starch has inherent structural limitations, such as its inferior glass transition temperature (Tg), water vapour permeability, and mechanical properties, which are crucial to the synthesis and durability of bioplastics. The starch remains amorphous below their T g and will be free-flowing above their T g [ 10 ]. Furthermore, high free volume and minimum cohesiveness between the starch chains hinder the achievement of desirable moisture barrier and mechanical properties [ 11 , 12 ]. Previous works opted for a single modification approach, either esterification or heat treatment, to improve the mechanical, moisture barrier, and thermal properties of maize starch [ 13 ], cassava starch [ 14 ], and wheat starch [ 15 ]. Some studies employed the heat treatment approach to enhance the functional properties of cassava starch [ 16 ] and potato starch [ 17 ]. A work used an integer-rated approach of moisture heat treatment and oxidation to improve the functional properties of starch films [ 18 , 19 ]. Therefore, this study aimed to develop a novel thin film through an innovative, integrated approach combining an etherification reaction and dry heat treatment. Reports on the combined effects of cross-linking and dry heat treatment on starches from different sources are limited, particularly concerning their physicochemical, mechanical, thermal, and biodegradation properties. To date, no study has comprehensively explored the combined effects of cross-linking and dry heat treatment on India’s underutilized indigenous finger millet starch. This study examines how cross-linking improves the structural integrity of starch matrices under dry heat treatment, highlighting its influence on the physicochemical, morphological, thermal, and biodegradation properties of thin films. Materials and Methods CA and calcium chloride were purchased from Loba Chem, India. An old, isolated NFS was used in this research work (Gautam et al., 2022). All the chemicals used in this study were of analytical grade. CA/DHT modification of NFS Uniform-sized NFS (10 g) and CA (3%, 5%, & 8% w/w of total dry starch) were carefully mixed to obtain mixtures. Mixtures were heated at 130°C for 5 hr in a hot air oven. All mixtures of modified starch were carefully crushed and screened through an 80-mesh sieve after reaching 25°C. All mixtures were washed with 80% ethanol to extract unreacted CA. Modified finger millet starch was dried for 12 h at 45 ◦ C and preserved in airtight polyethene bags for further applications. Preparation of films MFS (3g) and sorbitol (30% w/w of total starch) were blended into 100 mL of distilled water to form the mixture. At 90°C for 20 min, the starch mixture was continuously mixed using a magnetic stirrer to obtain starch solutions. A speed homogenizer was used to get a homogeneous starch film-forming solution. Entrapped air bubbles in homogeneous starch solution were removed using a vacuum oven. A 5 mL film-forming starch solution was carefully spread onto the Petri dishes (9 mm) and dried overnight at 25°C. All dried films were carefully removed and stored in airtight bags for subsequent analysis. The film notation is MFS3 (3% CA), MFS5 (5% CA), and MFS8 (8% CA), while NFS may be treated as a reference film. Proximate analysis The moisture, ash, and amylose contents of native and modified starches were evaluated according to the methodologies described in our previous work [ 19 ]. The moisture content was calculated according to Eq. (1). $$\:\text{M}\text{o}\text{i}\text{s}\text{t}\text{u}\text{r}\text{e}\:\text{c}\text{o}\text{n}\text{t}\text{e}\text{n}\text{t}\:\left(\text{M}\text{C}\right)=\frac{{\text{w}}_{1}-{\text{w}}_{2}}{{\text{w}}_{1}}\times\:100\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\left(1\right)$$ Where w1 and w2 represent the initial and dried weights of starch samples (g), respectively. Film Thickness (TH) Analysis Thickness measurements were obtained from six distinct locations across the film surface employing a digital micrometer (Mitutoyo, Japan) with a precision of 0.001 mm. Moisture Content (MC) Analysis MC was determined by oven-drying 2 cm × 2 cm samples at 105°C for 24 h. Variations in sample weight were calculated using Eq. (2). M \(\:\text{o}\text{i}\text{t}\text{u}\text{r}\text{e}\:\text{C}\text{o}\text{n}\text{t}\text{e}\text{n}\text{t}\:\left(\text{%}\right)=\frac{{\text{W}}_{1}-{\text{W}}_{2}}{{\text{W}}_{1}}\times\:100\dots\:\dots\:\dots\:..\left(2\right)\) Meanwhile, w1 and w2 represent the initial weight (g) and dried weight (g) of the samples, respectively. Swelling Index (SI) Analysis SI of the film was evaluated using the gravimetric method. Samples measuring 2 cm × 2 cm were dried in a preheated oven at 105 ± 1°C for 24 h and weighed (m 1 ). Subsequently, the dried sample was immersed in a beaker containing 15 mL of distilled water for 5 min. Excess water from the swollen sample was eliminated using tissue paper, and the sample was reweighted (m 2 ). SI was determined using Eq. (3). $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{S}\text{I}\:\left(\text{%}\right)=\frac{{\text{m}}_{1}-{\text{m}}_{2}}{{\text{m}}_{2}}\times\:100\dots\:\dots\:\dots\:\dots\:\left(3\right)$$ Whereas, m 1 and m 2 are the weight of dried (g) and wet samples (g), respectively Film Solubility (SF) Analysis Initially, the sample was dried in a preheated oven maintained at 105 ± 1°C for 24 h and weighed (m i ). A sample measuring 2 cm × 2 cm was submerged in distilled water for 24 h. Afterwards, the remaining undissolved portion of the sample was recovered from the water and dried at 25 ± 1°C for an additional 24 h. The weight of the dried sample was then recorded (m f ). The variation in the weight of the sample was evaluated using Eq. (4) $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{S}\text{F}\:\left(\text{%}\right)=\frac{{\text{m}}_{\text{i}}-{\text{m}}_{\text{f}}}{{\text{m}}_{\text{i}}}\times\:100\dots\:\dots\:\dots\:\dots\:\left(4\right)$$ Where, mi and mf are the weights of dried (g) and insoluble samples (g). Opacity (Op) Analysis The L*, a*, and b* values of each film were determined using a HunterLab colourimeter. Calibration of the colourimeter involved setting L* values to represent black (0) and white (100). Conversely, a* values ranged from negative (indicating green) to positive (indicating red), and b* values ranged from negative (indicating blue) to positive (indicating yellow). Calibration was performed using black-and-white plates, following the procedure outlined by Gautam et al. (2022). The opacity (Op) was determined according to Eq. (5). $$\:Op=\frac{{{L}^{*}}_{B}}{{{L}^{*}}_{w}}\times\:100\dots\:\dots\:\dots\:\dots\:\left(5\right)$$ Water Vapor Permeability (WVP) Analysis WVP of the films was evaluated according to ASTM E95-96 standards. Beakers were filled with dried calcium chloride and sealed with the film. Vacuum grease was applied to ensure a secure seal and prevent moisture leakage from the joints between the beaker and film. These prepared beakers were then placed in an incubator filled with distilled water and put in a preheated oven set to 25 ± 1°C. The changes in beaker weight were recorded at fixed intervals, and the recorded data were used to calculate WVP (gs-1 m-1 Pa-1) using Eq. (6). $$\:\:\text{W}\text{a}\text{t}\text{e}\text{r}\:\text{V}\text{a}\text{p}\text{o}\text{r}\:\text{P}\text{e}\text{r}\text{m}\text{e}\text{a}\text{b}\text{i}\text{l}\text{i}\text{t}\text{y}=\frac{\frac{{\Delta\:}\text{w}}{\text{T}}\times\:\text{L}}{\text{A}\:\left({\text{P}}_{\text{i}}-{\text{P}}_{\text{o}}\right)}\dots\:\dots\:\dots\:\dots\:\left(6\right)$$ Where \(\:\frac{{\Delta\:}w}{\text{T}}\) is the gain in beaker weight per unit time (g/h), L is film thickness (mm), A is the area of the beaker (cm 2 ), and P i –P o is the pressure difference (Pa), respectively. Mechanical Properties The mechanical properties of the films, including tensile strength (TS) and elongation at break (E%), were determined using a universal testing machine (AEC1112-ACD 2KN) in accordance with ASTM D638-14. The experimental parameters included a crosshead speed of 50 mm/min and an initial grip distance of 50 mm. TS and E% were calculated using Equations (7) and (8), respectively. $$\:\text{T}\text{S}\left(\text{M}\text{P}\text{a}\right)=\frac{\text{F}}{\text{A}}\dots\:\dots\:\dots\:\dots\:\left(7\right)$$ $$\:\text{E}\:\left(\text{%}\right)=\frac{\varDelta\:\text{x}}{\text{x}}\dots\:\dots\:\dots\:\dots\:.\:\left(8\right)$$ Biodegradable Study Biodegradability refers to the natural breakdown and decomposition of complex molecules into simple ones by microorganisms within a short period. Tests were conducted using standard soil burial degradation methods with regular soil and compost under ambient conditions for 7–30 days to evaluate biodegradation. Specimens measuring 1 cm × 1 cm were prepared for analysis. These specimens were placed in plastic containers filled with a mixture of regular soil and compost, ensuring a burial depth of less than 2 cm from the opening. Environmental conditions were controlled to maintain a humidity level of 90 ± 2% and a constant temperature of 25 ± 1 ºC. The weight loss of the film specimens was systematically monitored at weekly intervals to track changes over time. This monitoring was conducted at regular one-week intervals. This methodology measures biodegradation rates (Amaraweera et al., 2021; Nandi and Guha, 2023). $$\:\:\:\text{M}\text{o}\text{i}\text{s}\text{t}\text{u}\text{r}\text{e}\:\text{c}\text{o}\text{n}\text{t}\text{e}\text{n}\text{t}\:\left(\text{%}\right)=\frac{\text{I}\text{n}\text{i}\text{t}\text{i}\text{a}\text{l}\:\text{w}\text{t}-\text{F}\text{i}\text{n}\text{a}\text{l}\:\text{w}\text{t}}{\text{I}\text{n}\text{i}\text{t}\text{i}\text{a}\text{l}\:\text{w}\text{t}}\times\:100\dots\:\dots\:\dots\:..\left(7\right)$$ FTIR Analysis FTIR spectroscopy (Bruker Vector 22) was used to investigate potential interactions within the films' matrices. Spectra of the films were acquired across the 4000 − 500 cm − 1 wavenumber range with a resolution of 4 cm. XRD Analysis XRD patterns of the films were obtained using a Shimadzu model XRD-6000. The analysis was conducted over the 2θ range from 3° to 90° at a scan speed of 2° min − 1 . Cu Kα radiation, with a wavelength of 1.542 Å and operating at 40 kV and 40 mA, was employed for the analysis. SEM Analysis SEM (SU1510, Hitachi, Japan) was employed to examine the surface morphology of the films. This facilitated the identification of structural interactions resulting from modifications within the film matrix. Observations were made at various magnifications to ensure a comprehensive understanding of the sample characteristics. TGA Analysis The thermal stability of the films was investigated using a Shimadzu TGA-50 instrument under a nitrogen flow rate of 50 mL min − 1, with a heating rate of 10°C min − 1 . The temperature range for analysis spanned 50–450°C. Statistical analyses All tests were performed in triplicate, and outcomes were presented as means ± standard deviation. All outcomes were analysed using Origin Pro 2022 (Northampton, USA). All statistical tests were two-tailed with a significance threshold at p < 0.05. Results and discussion Moisture, Ash, and Amylose Content Analysis The Moisture and ash content of native and modified starches are summarized in Table 1 . Functionality, film formation character, texture, and stability of starch are critically dependent on moisture content. Native starch exhibits a moisture content of 12.09 ± 0.6, while modified starches (3, 5, & 8% CA) are 10.18 ± 0.94, 9.42 ± 1.17 and 10.57 ± 0.89. Modified starch with 5% CA had the lowest moisture content compared to native starch and other modified starches. It appears that as the CA level in the starch matrix exceeds 5%, the moisture content increases. An increase in the moisture content might be related to unreacted CA in the starch matrix. A decrease in moisture content aligns with Gautam et al. (2022), attributed to ester linkages between CA and starch. It is further supported by DHT [ 22 ], which aims to provide alternative ester bonds in the starch network. Similarly, Hong-Ju He et al. (2025) reported a decrease in moisture content in heat-moisture-treated finger millet starch, confirming the role of thermal treatments in enhancing starch stability [ 23 ]. Native starch exhibited an ash content of 0.0031 ± 1.60, which is higher than that of modified starches. (Table 1 ), indicating improved purity and cleaner processing of the modified starch. The higher ash value in native starch may be related to elevated mineral content. A reduction in the ash content after CA/DHT may be attributed to the decomposition of mineral and organic residues, resulting in a cleaner product [ 24 ]. Native starch exhibits an amylose content of 15.2%, while modified starches depict an amylose content range of 16.8–21.8% (Table 1 ). An incremental effect of amylose content. can be connected to more efficient exposure of longer linear segments through hydrolysis and depolymerisation of the amylopectin [ 25 ]. An integrated approach combining DHT and CA modification enhances the energy supplied, facilitating the structural transition of amylose from a coil to a helical form [ 26 ]. Table 1 Moisture, ash, and amylose content of native and modified starch Starch Samples Moisture Content (%) Ash Content (g) Amylose content (%) Native starch 12.09 ± 1.37 0.0031 ± 1.60 39.03 ± 0.66 CA (3%) 10.18 ± 0.94 0.0059 ± 1.41 40.16 ± 0.97 CA (5%) 9.42 ± 1.17 0.0061 ± 1.95 41.63 ± 0.81 CA (8%) 10.57 ± 0.89 0.0062 ± 0.98 41.12 ± 1.20 TH Analysis TH plays a crucial role in food packaging, directly influencing key parameters such as film moisture permeability, opacity, and mechanical properties. TH values of all NFS, MFS3, MFS5, and MFS8 are shown in Table 2 . After the CA/DHT, a slight change in TH was observed, possibly due to a disturbance in the arrangement of polymer chains within the starch matrix. Similarly, Kumar et al. (2020) suggested a decrease in film TH after CA modification of corn starch [ 27 ]. Unlike NFS films, MFS3, MFS5, and MFS8 exhibited a slightly higher thickness. A variation in the TH might be related to the internal rearrangement of polymeric chains in the starch matrix, which can be altered due to CA/DHT, leading to an increase in TH [ 28 ]. MC Analysis Table 2 presents the MC values of MFS3, MFS5, MFS8, and NFS. The MC of NFS was 10.32%, higher than that of MFS3, MFS5, and MFS8. A minimum MC of 6.07% was noticed in the MFS 5 . MFS 8 shows an MC of 7.95%, higher than MFS 3 (6.07%). These findings are consistent with earlier research by Azevedo et al. (2015), who reported that the MC of whey protein-based films decreased after CA treatment [ 29 ]. Similarly, Wenhao Li et al. (2020) reported that the MC of mung bean starch decreased after repeated dry heat treatment [ 30 ]. The reduction in MC can be attributed to improved intra- and intermolecular interactions among the polymer chains induced during the treatments. This leads to hydrogen bonding between the functional groups (Starch-CA), decreasing the availability of free hydroxyl groups in the starch matrix and lowering MC (Kumar et al., 2020; Sandhu et al., 2020). SF Analysis Table 2 shows that the SF of MFS3, MFS5, and MFS8 was substantially lower than that of NFS (38.94%). MFS3, MFS5, and MFS8 exhibit SF values of 20.34%, 18.67%, and 21.83%, respectively. MFS5 displayed the greatest reduction, indicating the most effective restriction of water uptake. This pronounced decrease results from CA-induced esterification and DHT-mediated structural reorganization, which reinforce amylose–amylopectin interactions and reduce matrix hydrophilicity. These findings are consistent with previous studies reporting suppressed swelling behaviour in citric-acid-crosslinked starch materials by Sandhu et al. (2020), who demonstrated a reduction in the SF of sorghum starch after cross-linking [ 32 ]. A similar trend was observed in SF of potato starch/chitosan-based films modified with citric acid by Wu et al. (2019). Another study reported that the film's water solubility decreased after heat-moisture treatment [ 34 ]. Another research study suggested that CA and DHT in the starch matrix induce a cross-linked structure, reducing the availability of -OH sites on the starch matrix after modification, which may be responsible for a decrease in water interaction (Zou et al., 2021). A decrease in SF films may be attributed to the formation of a crosslinked network among starch chains during modification procedures, resulting in compact, homogeneous films with reduced SF [ 36 ]. SI Analysis SI was measured to assess water–polymer chain interactions within the starch matrix, reflecting the response of linear, branched, and double-helix starch structures (Liu et al., 2019). Table 2 shows an apparent reduction in SI for MFS3, MFS5, and MFS8 compared to NFS (51.97%). The SI values of MFSF3 and MFSF8 were markedly lower, with MFSF5 exhibiting the lowest SI (16.29%), indicating the most significant suppression of water uptake among the modified films. According to Saliu et al. (2017), the SI of the films is dependent on their compactness. This indicates that the SI of the films increased due to improved compactness following CA/DHT treatment [ 38 ]. Another study by Menzel et al. (2020) also reported that the SI of starch films decreased after oxidation, cross-linking, and reinforcing methods. The reduced SI results from CA/DHT-induced cross-linking and molecular tightening, which limit the number of available hydroxyl groups and restrict starch–water interactions (Majzoobi et al., 2012). Table 2 Functional properties of NFS and MFS 3 , MFS 5 , and MFS 8 Film’s Samples TH (mm) MC (%) SI (%) SF (%) Op (%) NFS 0.09 ± 0.08 10.32 ± 0.71 51.97 ± 0.88 38.94 ± 0.72 31.03 ± 0.11 MFS3 0.11 ± 0.09 10.05 ± 0.15 20.56 ± 0.38 21.83 ± 0.16 23.09 ± 1.1 MFS5 0.12 ± 0.27 6.07 ± 0.09 16.29 ± 0.52 18.67 ± 0.08 21.17 ± 0.02 MFS8 0.11 ± 0.12 7.95 ± 0.06 19.46 ± 0.29 20.34 ± 0.09 20.06 ± 0.17 Op Analysis Table 2 shows that the Op of NFS (31.03%) is substantially higher than that of the MFS3, MFS5, and MFS8. Among the modified films, MFS8 exhibits the lowest Op value of 20.06%, indicating reduced light transmission. The results clearly demonstrate that CA (3%, 5%, and 8%) with DHT progressively decreases film transparency, indicating a denser, more compact matrix structure. The results and trends of this work are consistent with those reported by Kumar (2021), which show that adding CA reduces the opacity and lightness of starch films (Table 2 ). In a work reported by E. Grossmann et al (2004), it was suggested that opacity in yam starch films is strongly thickness-dependent, with thicker films exhibiting greater light scattering and thus higher opacity [ 41 ]. Similarly, E.R. Zavareze et al. (2012) reported that the opacity of potato starch films increased after oxidation and heat-moisture treatment [ 42 ]. The reduction in optical density (Op) is attributed to decreased crystallinity, which enhances light transmission through the film and consequently lowers its overall Op [ 42 ]. Mechanical Property Analysis Tensile strength (TS) and elongation (E%) measurements are summarized in Table 3 . The TS of the NFS was 9.24 N/mm², whereas CA/DHT modification produced a substantial enhancement, with TS values ranging from 27.00 N/mm² (MFS3) to 29.82 N/mm² (MFS8). MFS8 exhibited the highest strength among the modified films. Overall, CA/DHT treatment significantly improved the load-bearing capacity of the starch films. This finding is consistent with the results reported by Fernández-Pan et al. (2010), who observed enhanced mechanical properties in films made with chitosan at increased chitosan content and higher drying temperatures. Tapia-blácido et al. (2013) found that amaranth flour films showed higher strength and reduced flexibility when plasticized with glycerol and processed under dry-heating conditions. Sharma et al. (2020) reported enhanced tensile strength in films prepared with Foba bean starch as the cross-linking agent. According to Narasagoudr et al. (2020), the mechanical properties of chitosan-polyvinyl alcohol films improved after heating with boswellic acid [ 47 ]. WVP Analysis WVP is a critical parameter in food packaging, as it governs moisture transfer between the environment and packaged products. Materials with low WVP are essential for protecting moisture-sensitive foods. As shown in Table 3 , CA/DHT treatment substantially improved the barrier properties of films. The WVP of NFS (3.81 × 10⁻⁹ g s⁻¹ m⁻¹ Pa⁻¹) decreased sharply to 1.26 × 10⁻⁹ g s⁻¹ m⁻¹ Pa⁻¹ in MFS3, representing the lowest WVP among all modified films. The slightly higher WVP observed in MFS8 may be attributed to trace amounts of unreacted citric acid, which acts as a plasticizer, thereby increasing matrix permeability. These results align with earlier studies, which report that cross-linking agents reduce WVP by creating denser polymer networks and limiting moisture diffusion [ 35 , 48 ]. Similarly, Mehboob et al. (2020) found that adding citric acid improved the WVP of sorghum starch films. The reduction in WVP is primarily attributed to CA/DHT-induced cross-linking, which restricts starch chain mobility and forms a denser, less permeable polymer network, thereby slowing water diffusion through the film matrix (Yang et al., 2021). Table 3 Mechanical and barrier properties of NFS and MFS3, MFS5, and MFS8 Film’s Samples TS (N/mm 2 ) E (%) WVP (gs −1 m −1 Pa − 1 *10 − 9 ) NFS 9.24 ± 0.514 28.77 ± 1.42 3.81 ± 0.05 MFS3 27.00 ± 0.21 21.28 ± 0.66 1.26 ± 0.37 MFS5 29.19 ± 0.29 22.75 ± 1.18 1.65 ± 0.432 MFS8 29.82 ± 0.22 20.15 ± 0.91 1.67 ± 0.41 FTIR Analysis FTIR analysis was conducted to examine the changes in functional groups and molecular interactions induced by CA/DHT modification. As shown in Fig. 1 , all films exhibited similar spectral profiles; however, a distinct new peak at ~ 1730 cm⁻¹ appeared in MFS3, MFS5, and MFS8, confirming the formation of carbonyl groups due to citric-acid–induced esterification [ 7 ]. The broad band at 3000–3700 cm⁻¹ corresponds to O–H stretching, while the peak at ~ 2930 cm⁻¹ is attributed to C–H stretching. Peaks near 1023 and 990 cm⁻¹ represent C–O stretching, and the band around 1650–1640 cm⁻¹ is associated with bound water [ 40 ]. Notably, modified films (MFS3, MFS5, MFS8) showed narrower peaks and slight intensity shifts, indicating reduced hydrogen bonding and structural reorganization within the starch matrix following CA/DHT treatment. A similar study was conducted by [ 40 ], in which citric acid was added to a potato starch film. XRD Analysis The XRD profiles (Fig. 2 ) reveal that NFS displays a characteristic A-type diffraction pattern with peaks at 15°, 17.11°, 19.74°, 22.12°, and 23.82°. Notably, the MFS3, MFS5, and MFS8 retained the same crystalline pattern, indicating that the CA/DHT modification altered polymer interactions without changing the fundamental A-type crystallinity. A similar effect on XRD of sweet potato starch was noted by Hung et al. (2014) after a combination of citric acid and heat-moisture treatment. Kwon et al. (2019) also suggested that DHT and acids did not alter the XRD patterns of potato starch. The relative crystallinity of MFS3, MFS5, and MFS8 was lower than that of NFS, accompanied by a noticeable reduction in diffraction intensity after CA/DHT treatment. This indicates partial disruption of ordered regions within the starch matrix. Duyen et al. (2020) also reported a reduction in the peak intensity of mung bean starch after CA and hydrothermal treatment. A reduction in the relative crystallinity of the films after CA/DHT might be related to the fact that CA/DHT could break down starch molecules into shorter chains, facilitating the formation of double-helical chains in the starch matrix and increasing the relative crystallinity of modified starch films [ 7 , 54 ]. SEM Analysis SEM micrographs (Fig. 3 ) reveal that NFS possesses a generally homogeneous and continuous morphology, but exhibits minor surface defects, such as bubbles and microcracks. In contrast, the MFS3, MFS5, and MFS8 display smoother, more uniform, and highly continuous surfaces with no visible cracks or voids, indicating improved film integrity and matrix compactness following modification. Punia, Bangar, and colleagues (2021) reported enhanced surface morphology in films produced from pearl millet starch [ 55 ]. Similar changes in the morphology of rice starch and rice flour films after heat and moisture treatment [ 56 ]. Another study also claimed that modification processes can enhance film morphology by promoting granule fusion and reducing granule surface pores [ 57 ]. TGA Analysis Variation in the thermal stability of films after CA/DHT was studied using TGA curves, as illustrated in Fig. 4 . The decomposition stages of the films were categorised into three regions spanning from room temperature to 650°C. Initially, film weight loss occurred between 50 ºC and 250 ºC, likely due to the vaporization of unbound water [ 57 ]. MFS3, MFS5, and MFS8 exhibited lower weight loss (5.26%) than NFS (6.92%), indicating improved resistance to water evaporation in the former. In the second region, weight loss for NFS reached 69.44%, whereas the modified starch film exhibited a reduced weight loss of 60.39% over the temperature range of 250°C to 325°C. A decrease in weight was related to bound water and the degradation of film-forming components [ 58 ]. The temperatures at which weight loss occurred in the films made with MFS3, MFS5, and MFS8 were higher than in the NFS film. This suggests that a combination of CA/DHT improved thermal stability [ 59 ]. Biodegradability analysis Table 4 presents the degradation rate of MFS3, MFS5, MFS8, and NFS. A higher weight loss rate was noted in NFS samples compared to MFS3, MFS5, and MFS8. NFS samples exhibited 80% to 100% weight loss in compost, while the average weight loss in MFS3, MFS5, and MFS8 was approximately 82%. v. Similar outcomes were presented by Seligra et al. (2016), who observed that the films with high hydrophilic mass showed high biodegradability. Table 4 Biodegradable study of NFS and MFS3, MFS5, and MFS8 samples using soil and compost material. Degradation (%) Soil Compost Days NFS sample MFS NFS sample MFS 0 0 0 0 0 7 15.63 ± 0.17 11.08 ± 0.13 26.16 ± 0.88 15.03 ± 0.19 14 37.93 ± 0.41 33.31 ± 0.55 42.1 ± 0.67 37.99 ± 1.4 24 70.65 ± 0.25 49.5 ± 0.19 83.55 ± 0.50 59.5 ± 0.31 28 100 ± 1.1 74.47 ± 0.63 100 ± 1.3 85.5 ± 0.97 Conclusion This work presents a novel combination of physical and chemical methods to effectively modify the structural, thermal, physicochemical, and biodegradability properties of finger millet starch films. Native modified with CA/DHT produced high-quality thin films, demonstrating excellent starch–CA internal network and compatibility, and yielding thin films with strong mechanical, optical, barrier, thermal, and structural properties. CA/DHT did not damage the inherent starch network but did improve molecular interactions and the amorphous region. Furthermore, the CA/DHT modification improved the films' compactness, homogeneity, and biodegradation rate, illustrating superior material performance. Our results demonstrated that a novel combination of physical and chemical methods holds potential applications in both food and non-food industries. Declarations Conflict of Interest There are no conflicts of interest among the authors Ethics Approval: This study did not involve human participants or animals and therefore did not require ethical approval. Consent to Participate: Not applicable, as this study did not involve human participants. Consent to Publish: Not applicable. Funding: The Ministry of Education, India, NIT Jalandhar, and CSIR-CBRI, Roorkee, provide the fellowship, consumables, and research infra for this research work Author Contribution NG: Conceptualization, Methodology, Investigation, Formal analysis, Data curation, Writing – original draft, Visualization.SR: Methodology, Investigation, Validation, Data curation, Writing – review & editing.RK: Supervision, Resources, Project administration, Conceptualization, Formal analysis, Writing – review & editing.SKY: Supervision, Conceptualization, Validation, Writing – review & editing. Acknowledgment This research work is supported by the CSIR-Central Building Research Institute (CSIR-CBRI), BTKIT, Dwarahat, and the NIT Jalandhar, India, in terms of research and testing facilities. Data Availability The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. References Gautam N, et al. 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Effect of drying conditions and plasticizer type on some physical and mechanical properties of amaranth fl our fi lms. LWT - Food Sci Technol LWT - Food Sci Technol. 2013;50:392–400. Sharma V, Kaur M, Sandhu KS, et al. Effect of cross-linking on physico-chemical, thermal, pasting, in vitro digestibility and film-forming properties of Faba bean (Vicia faba L.) starch. Int J Biol Macromol. 2020;159:243–9. Narasagoudr SS, Hegde VG, Chougale RZ, et al. Influence of boswellic acid on multifunctional properties of chitosan/poly (vinyl alcohol) films for active food packaging. Int J Biol Macromol. 2020;154:48–61. Narasagoudr SS, Hegde VG, Chougale RB, et al. Influence of boswellic acid on multifunctional properties of chitosan/poly (vinyl alcohol) films for active food packaging. Int J Biol Macromol. 2020;154:48–61. Gao Y, Zheng H, Wang J, et al. Physicochemical properties of zein films cross-linked with glutaraldehyde. Polym Bull. 2022;79:4647–65. Mehboob S, Ali TM, Sheikh, et al. Effects of cross linking and/or acetylation on sorghum starch and film characteristics. Int J Biol Macromol. 2020;155:786–94. Yang J, Ching YC, Chuah CH, et al. Preparation and characterization of starch-based bioplastic composites with treated oil palm empty fruit bunch fibers and citric acid. Cellulose. 2021;28:4191–210. Hung P, Van, My NTH, Phi NTL. Impact of acid and heat-moisture treatment combination on physicochemical characteristics and resistant starch contents of sweet potato and yam starches. Starch/Staerke. 2014;66:1013–21. Kwon C, Kim HR, Moon TW et al. Structural and physicochemical characteristics of granular malic acid-treated sweet potato starch containing heat-stable resistant starch. J Chem. 2019, 2019, 2903252. Duyen TTM, Huong NTM, Phi NTT, et al. Physicochemical properties and in vitro digestibility of mung-bean starches varying amylose contents under citric acid and hydrothermal treatments. Int J Biol Macromol. 2020;164:651–8. Su C, Zhao K, Zhang B, Liu Y, Jing L, Wu H, Gou M, Jiang H, Zhang G, Li W. The molecular mechanism for morphological, crystal, physicochemical and digestible property modification of wheat starch after repeated versus continuous heat-moisture treatment. LWT- Food Sci Technol. 2020;129:109399. Punia Bangar S, Nehra M, Siroha AK, Petrů et al. Development and characterization of physical modified pearl millet starch-based films. Foods 2021, 10. Majzoobi M, Pesaran Y, Mesbahi G, et al. Physical properties of biodegradable films from heat-moisture-treated rice flour and rice starch. Starch/Staerke. 2015;67:1053–60. Gao Y, Zheng H, Wang J, et al. Physicochemical properties of zein films cross-linked with glutaraldehyde. Polym Bull. 2022;79:4647–65. Santos LM, Ingrid IA, Roa JPB et al. Evaluation of the effects of organic acids on the properties of thermoplastic starch. Polym Bull 2025, 3063–83. Khan B, Khan Niazi MB, Jahan Z, et al. Effect of ultra-violet cross-linking on the properties of boric acid and glycerol co-plasticized thermoplastic starch films. Food Packag Shelf Life. 2019;19:184–92. Seligra PG, Medina Jaramillo C, Famá L. Biodegradable and non-retrogradable eco-films based on starch-glycerol with citric acid as crosslinking agent. Carbohydra Polym. 2016;138:66–74. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8660714","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":599090255,"identity":"6e5cad5f-2afd-4493-afd7-48207ef606e0","order_by":0,"name":"Naina Gautam","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYHADxsYHH4AUGzuR6iUYGJibDWeAtDATr4W9TZoHxCSkxZz97DHJLzWH6/inHWw2tvm1TZ6PmYHxw8cc3Fose/LSpGWOHZaQuJ3Y+Di377ZhGzMDs+TMbbi1GBzIMZOWYDsswXA7sdk4t+c2I1ALGzMvPi3n3wC1/DssIX87sU3asue2PWEtN3LMJD+2HZYwAGlh+AEkCWt5Y2zN2JcuuRHoMMPehtvJbcyMzfj9cj7H8OaPb9b8crfTHz748ee27fz25oMfPuLRAgLMPDAWYxuYbMCvHqTkB5z5h6DiUTAKRsEoGIEAADnCUmdRZHtMAAAAAElFTkSuQmCC","orcid":"","institution":"Dr. B. R. Ambedkar National Institute of Technology Jalandhar","correspondingAuthor":true,"prefix":"","firstName":"Naina","middleName":"","lastName":"Gautam","suffix":""},{"id":599090259,"identity":"857f4734-e060-4c74-81c6-a0e8c908dc07","order_by":1,"name":"Shweta Rawat","email":"","orcid":"","institution":"Bipin Tripathi Kumaon Institute of technology","correspondingAuthor":false,"prefix":"","firstName":"Shweta","middleName":"","lastName":"Rawat","suffix":""},{"id":599090261,"identity":"20016205-4340-4756-8ad2-e1735d888ab8","order_by":2,"name":"Raj Kumar","email":"","orcid":"","institution":"Central Building Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Raj","middleName":"","lastName":"Kumar","suffix":""},{"id":599090262,"identity":"49a31f2c-bdb7-4302-a852-f6ae58b06ce8","order_by":3,"name":"Shashikant Yadav","email":"","orcid":"","institution":"Dr. B. R. Ambedkar National Institute of Technology Jalandhar","correspondingAuthor":false,"prefix":"","firstName":"Shashikant","middleName":"","lastName":"Yadav","suffix":""}],"badges":[],"createdAt":"2026-01-21 14:00:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8660714/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8660714/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103901531,"identity":"67263365-599a-45fa-bde9-9cf64ae12556","added_by":"auto","created_at":"2026-03-04 09:59:51","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":74098,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR analysis of NFS (A), MFS (B)\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8660714/v1/a5e40ff9ef80baa2b01297f1.jpeg"},{"id":103901532,"identity":"ecd54ae8-a18e-4601-a5e5-8b9c5ab1eeeb","added_by":"auto","created_at":"2026-03-04 09:59:51","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":57374,"visible":true,"origin":"","legend":"\u003cp\u003eXRD analysis of NFS (A) and MFS (B)\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8660714/v1/e6aa7a91fb9a5d887d750c67.jpeg"},{"id":103901534,"identity":"2b3bb40d-e494-46b1-816d-4c8cf323e62b","added_by":"auto","created_at":"2026-03-04 09:59:51","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":115798,"visible":true,"origin":"","legend":"\u003cp\u003eSEM analysis of NFS (A\u0026amp;B) and MFS (C\u0026amp;D)\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8660714/v1/2c911ba90080921c323e9268.jpeg"},{"id":104401685,"identity":"180c4303-b2b0-4d18-b6f5-ddbfe1987ed4","added_by":"auto","created_at":"2026-03-11 12:13:15","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":53104,"visible":true,"origin":"","legend":"\u003cp\u003eTGA peaks of NFS (A) and MFS (B)\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8660714/v1/a4d6db2f903e294832ffe2cf.jpeg"},{"id":104408567,"identity":"880ec74d-c8e8-4f79-8192-b1ee429f96b1","added_by":"auto","created_at":"2026-03-11 12:42:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1193853,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8660714/v1/e91dff0a-33ac-4536-a22c-a7152d25ba48.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Physico-Chemical Tailoring of Finger Millet Starch for Improved Barrier and Mechanical Performance","fulltext":[{"header":"Highlights","content":"\u003cul\u003e\n \u003cli\u003eFilm morphology becomes smoother, denser, and more uniform.\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Mechanical strength and barrier performance are greatly enhanced.\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Relative crystallinity is markedly influenced by CA/DHT treatment.\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;CA/DHT modification improves thermal stability and biodegradability.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003ePlastics have become integral parts of households due to their multiple uses and affordable cost; however, their non-biodegradability poses a serious threat to both humans and the environment. As a result, accumulation in ecology is continuously increasing due to improper management of recycling and disposal [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Among all plastics, the food packaging sector generates approximately 40% of plastic waste [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Hence, biodegradable materials derived from renewable resources can serve as an alternative to synthetic plastics. Bioplastic-derived plant sources have gained popularity due to their lower maintenance requirements compared to animal or microbial sources [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Among natural polymers, cellulose is the simplest and most abundant on Earth. Many derivatives have been developed through chemical and physical processes to enhance their utility. Among derivatives, biodegradable cellulose acetate showed excellent impact resistance, mechanical properties, and moldability [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, they are challenging to process, which limits their use as bioplastics. Abundance in nature, low cost, and thermoplastic behavior make starch a strong candidate for the synthesis of bioplastics. Amylose and amylopectin are the two main polymers of starch, in which amylose is linear, whereas amylopectin is a branched polymer [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Starch obtained from finger millet (Eleusine coracana) is cultivated in Asian and African countries. It is widely utilized for the preparation of drinks, cuisines, soups, sauces, ice cream, non-alcoholic beverages, porridge, ready-to-eat meals, confectionery, bakery goods, beer, and non-fermented foods due to its high nutritional value (carbohydrate (60\u0026ndash;70%), fat (1.5\u0026ndash;5%), protein (6.9%\u0026ndash;19.9%), fiber (12.9%\u0026ndash;20.0%, \u0026amp; minerals (2.4% and 4.0%) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Despite millet\u0026rsquo;s good nutritional and functional attributes, significant amounts of starch were found in its granules, which can serve as a low-cost raw material for the development of bioplastics [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Starch has inherent structural limitations, such as its inferior glass transition temperature (Tg), water vapour permeability, and mechanical properties, which are crucial to the synthesis and durability of bioplastics. The starch remains amorphous below their T\u003csub\u003eg\u003c/sub\u003e and will be free-flowing above their T\u003csub\u003eg\u003c/sub\u003e [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Furthermore, high free volume and minimum cohesiveness between the starch chains hinder the achievement of desirable moisture barrier and mechanical properties [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Previous works opted for a single modification approach, either esterification or heat treatment, to improve the mechanical, moisture barrier, and thermal properties of maize starch [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], cassava starch [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], and wheat starch [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Some studies employed the heat treatment approach to enhance the functional properties of cassava starch [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] and potato starch [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. A work used an integer-rated approach of moisture heat treatment and oxidation to improve the functional properties of starch films [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Therefore, this study aimed to develop a novel thin film through an innovative, integrated approach combining an etherification reaction and dry heat treatment. Reports on the combined effects of cross-linking and dry heat treatment on starches from different sources are limited, particularly concerning their physicochemical, mechanical, thermal, and biodegradation properties. To date, no study has comprehensively explored the combined effects of cross-linking and dry heat treatment on India\u0026rsquo;s underutilized indigenous finger millet starch. This study examines how cross-linking improves the structural integrity of starch matrices under dry heat treatment, highlighting its influence on the physicochemical, morphological, thermal, and biodegradation properties of thin films.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eCA and calcium chloride were purchased from Loba Chem, India. An old, isolated NFS was used in this research work (Gautam et al., 2022). All the chemicals used in this study were of analytical grade.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eCA/DHT modification of NFS\u003c/h2\u003e \u003cp\u003eUniform-sized NFS (10 g) and CA (3%, 5%, \u0026amp; 8% w/w of total dry starch) were carefully mixed to obtain mixtures. Mixtures were heated at 130\u0026deg;C for 5 hr in a hot air oven. All mixtures of modified starch were carefully crushed and screened through an 80-mesh sieve after reaching 25\u0026deg;C. All mixtures were washed with 80% ethanol to extract unreacted CA. Modified finger millet starch was dried for 12 h at 45 \u003csup\u003e◦\u003c/sup\u003eC and preserved in airtight polyethene bags for further applications.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePreparation of films\u003c/h3\u003e\n\u003cp\u003eMFS (3g) and sorbitol (30% w/w of total starch) were blended into 100 mL of distilled water to form the mixture. At 90\u0026deg;C for 20 min, the starch mixture was continuously mixed using a magnetic stirrer to obtain starch solutions. A speed homogenizer was used to get a homogeneous starch film-forming solution. Entrapped air bubbles in homogeneous starch solution were removed using a vacuum oven. A 5 mL film-forming starch solution was carefully spread onto the Petri dishes (9 mm) and dried overnight at 25\u0026deg;C. All dried films were carefully removed and stored in airtight bags for subsequent analysis. The film notation is MFS3 (3% CA), MFS5 (5% CA), and MFS8 (8% CA), while NFS may be treated as a reference film.\u003c/p\u003e\n\u003ch3\u003eProximate analysis\u003c/h3\u003e\n\u003cp\u003eThe moisture, ash, and amylose contents of native and modified starches were evaluated according to the methodologies described in our previous work [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The moisture content was calculated according to Eq.\u0026nbsp;(1).\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\text{M}\\text{o}\\text{i}\\text{s}\\text{t}\\text{u}\\text{r}\\text{e}\\:\\text{c}\\text{o}\\text{n}\\text{t}\\text{e}\\text{n}\\text{t}\\:\\left(\\text{M}\\text{C}\\right)=\\frac{{\\text{w}}_{1}-{\\text{w}}_{2}}{{\\text{w}}_{1}}\\times\\:100\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\left(1\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eWhere w1 and w2 represent the initial and dried weights of starch samples (g), respectively.\u003c/p\u003e\n\u003ch3\u003eFilm Thickness (TH) Analysis\u003c/h3\u003e\n\u003cp\u003eThickness measurements were obtained from six distinct locations across the film surface employing a digital micrometer (Mitutoyo, Japan) with a precision of 0.001 mm.\u003c/p\u003e\n\u003ch3\u003eMoisture Content (MC) Analysis\u003c/h3\u003e\n\u003cp\u003eMC was determined by oven-drying 2 cm \u0026times; 2 cm samples at 105\u0026deg;C for 24 h. Variations in sample weight were calculated using Eq.\u0026nbsp;(2).\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eM\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\text{o}\\text{i}\\text{t}\\text{u}\\text{r}\\text{e}\\:\\text{C}\\text{o}\\text{n}\\text{t}\\text{e}\\text{n}\\text{t}\\:\\left(\\text{%}\\right)=\\frac{{\\text{W}}_{1}-{\\text{W}}_{2}}{{\\text{W}}_{1}}\\times\\:100\\dots\\:\\dots\\:\\dots\\:..\\left(2\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/h2\u003e \u003cp\u003eMeanwhile, w1 and w2 represent the initial weight (g) and dried weight (g) of the samples, respectively.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSwelling Index (SI) Analysis\u003c/h3\u003e\n\u003cp\u003eSI of the film was evaluated using the gravimetric method. Samples measuring 2 cm \u0026times; 2 cm were dried in a preheated oven at 105\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u0026deg;C for 24 h and weighed (m\u003csub\u003e1\u003c/sub\u003e). Subsequently, the dried sample was immersed in a beaker containing 15 mL of distilled water for 5 min. Excess water from the swollen sample was eliminated using tissue paper, and the sample was reweighted (m\u003csub\u003e2\u003c/sub\u003e). SI was determined using Eq.\u0026nbsp;(3).\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{S}\\text{I}\\:\\left(\\text{%}\\right)=\\frac{{\\text{m}}_{1}-{\\text{m}}_{2}}{{\\text{m}}_{2}}\\times\\:100\\dots\\:\\dots\\:\\dots\\:\\dots\\:\\left(3\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eWhereas, m\u003csub\u003e1\u003c/sub\u003e and m\u003csub\u003e2\u003c/sub\u003e are the weight of dried (g) and wet samples (g), respectively\u003c/p\u003e\n\u003ch3\u003eFilm Solubility (SF) Analysis\u003c/h3\u003e\n\u003cp\u003eInitially, the sample was dried in a preheated oven maintained at 105\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u0026deg;C for 24 h and weighed (m\u003csub\u003ei\u003c/sub\u003e). A sample measuring 2 cm \u0026times; 2 cm was submerged in distilled water for 24 h. Afterwards, the remaining undissolved portion of the sample was recovered from the water and dried at 25\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u0026deg;C for an additional 24 h. The weight of the dried sample was then recorded (m\u003csub\u003ef\u003c/sub\u003e). The variation in the weight of the sample was evaluated using Eq.\u0026nbsp;(4)\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e\n$$\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{S}\\text{F}\\:\\left(\\text{%}\\right)=\\frac{{\\text{m}}_{\\text{i}}-{\\text{m}}_{\\text{f}}}{{\\text{m}}_{\\text{i}}}\\times\\:100\\dots\\:\\dots\\:\\dots\\:\\dots\\:\\left(4\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eWhere, mi and mf are the weights of dried (g) and insoluble samples (g).\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eOpacity (Op) Analysis\u003c/h2\u003e \u003cp\u003eThe L*, a*, and b* values of each film were determined using a HunterLab colourimeter. Calibration of the colourimeter involved setting L* values to represent black (0) and white (100). Conversely, a* values ranged from negative (indicating green) to positive (indicating red), and b* values ranged from negative (indicating blue) to positive (indicating yellow). Calibration was performed using black-and-white plates, following the procedure outlined by Gautam et al. (2022). The opacity (Op) was determined according to Eq.\u0026nbsp;(5).\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e\n$$\\:Op=\\frac{{{L}^{*}}_{B}}{{{L}^{*}}_{w}}\\times\\:100\\dots\\:\\dots\\:\\dots\\:\\dots\\:\\left(5\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eWater Vapor Permeability (WVP) Analysis\u003c/h2\u003e \u003cp\u003eWVP of the films was evaluated according to ASTM E95-96 standards. Beakers were filled with dried calcium chloride and sealed with the film. Vacuum grease was applied to ensure a secure seal and prevent moisture leakage from the joints between the beaker and film. These prepared beakers were then placed in an incubator filled with distilled water and put in a preheated oven set to 25\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u0026deg;C. The changes in beaker weight were recorded at fixed intervals, and the recorded data were used to calculate WVP (gs-1 m-1 Pa-1) using Eq.\u0026nbsp;(6).\u003cdiv id=\"Eque\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Eque\" name=\"EquationSource\"\u003e\n$$\\:\\:\\text{W}\\text{a}\\text{t}\\text{e}\\text{r}\\:\\text{V}\\text{a}\\text{p}\\text{o}\\text{r}\\:\\text{P}\\text{e}\\text{r}\\text{m}\\text{e}\\text{a}\\text{b}\\text{i}\\text{l}\\text{i}\\text{t}\\text{y}=\\frac{\\frac{{\\Delta\\:}\\text{w}}{\\text{T}}\\times\\:\\text{L}}{\\text{A}\\:\\left({\\text{P}}_{\\text{i}}-{\\text{P}}_{\\text{o}}\\right)}\\dots\\:\\dots\\:\\dots\\:\\dots\\:\\left(6\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eWhere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\frac{{\\Delta\\:}w}{\\text{T}}\\)\u003c/span\u003e\u003c/span\u003e is the gain in beaker weight per unit time (g/h), L is film thickness (mm), A is the area of the beaker (cm\u003csup\u003e2\u003c/sup\u003e), and P\u003csub\u003ei\u003c/sub\u003e\u0026ndash;P\u003csub\u003eo\u003c/sub\u003e is the pressure difference (Pa), respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eMechanical Properties\u003c/h2\u003e \u003cp\u003eThe mechanical properties of the films, including tensile strength (TS) and elongation at break (E%), were determined using a universal testing machine (AEC1112-ACD 2KN) in accordance with ASTM D638-14. The experimental parameters included a crosshead speed of 50 mm/min and an initial grip distance of 50 mm. TS and E% were calculated using Equations (7) and (8), respectively.\u003cdiv id=\"Equf\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equf\" name=\"EquationSource\"\u003e\n$$\\:\\text{T}\\text{S}\\left(\\text{M}\\text{P}\\text{a}\\right)=\\frac{\\text{F}}{\\text{A}}\\dots\\:\\dots\\:\\dots\\:\\dots\\:\\left(7\\right)$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equg\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equg\" name=\"EquationSource\"\u003e\n$$\\:\\text{E}\\:\\left(\\text{%}\\right)=\\frac{\\varDelta\\:\\text{x}}{\\text{x}}\\dots\\:\\dots\\:\\dots\\:\\dots\\:.\\:\\left(8\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eBiodegradable Study\u003c/h2\u003e \u003cp\u003eBiodegradability refers to the natural breakdown and decomposition of complex molecules into simple ones by microorganisms within a short period. Tests were conducted using standard soil burial degradation methods with regular soil and compost under ambient conditions for 7\u0026ndash;30 days to evaluate biodegradation. Specimens measuring 1 cm \u0026times; 1 cm were prepared for analysis. These specimens were placed in plastic containers filled with a mixture of regular soil and compost, ensuring a burial depth of less than 2 cm from the opening. Environmental conditions were controlled to maintain a humidity level of 90\u0026thinsp;\u0026plusmn;\u0026thinsp;2% and a constant temperature of 25\u0026thinsp;\u0026plusmn;\u0026thinsp;1 \u0026ordm;C. The weight loss of the film specimens was systematically monitored at weekly intervals to track changes over time. This monitoring was conducted at regular one-week intervals. This methodology measures biodegradation rates (Amaraweera et al., 2021; Nandi and Guha, 2023).\u003cdiv id=\"Equh\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equh\" name=\"EquationSource\"\u003e\n$$\\:\\:\\:\\text{M}\\text{o}\\text{i}\\text{s}\\text{t}\\text{u}\\text{r}\\text{e}\\:\\text{c}\\text{o}\\text{n}\\text{t}\\text{e}\\text{n}\\text{t}\\:\\left(\\text{%}\\right)=\\frac{\\text{I}\\text{n}\\text{i}\\text{t}\\text{i}\\text{a}\\text{l}\\:\\text{w}\\text{t}-\\text{F}\\text{i}\\text{n}\\text{a}\\text{l}\\:\\text{w}\\text{t}}{\\text{I}\\text{n}\\text{i}\\text{t}\\text{i}\\text{a}\\text{l}\\:\\text{w}\\text{t}}\\times\\:100\\dots\\:\\dots\\:\\dots\\:..\\left(7\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eFTIR Analysis\u003c/h2\u003e \u003cp\u003eFTIR spectroscopy (Bruker Vector 22) was used to investigate potential interactions within the films' matrices. Spectra of the films were acquired across the 4000\u0026thinsp;\u0026minus;\u0026thinsp;500 cm\u0026thinsp;\u0026minus;\u0026thinsp;1 wavenumber range with a resolution of 4 cm.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eXRD Analysis\u003c/h2\u003e \u003cp\u003eXRD patterns of the films were obtained using a Shimadzu model XRD-6000. The analysis was conducted over the 2θ range from 3\u0026deg; to 90\u0026deg; at a scan speed of 2\u0026deg; min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Cu Kα radiation, with a wavelength of 1.542 \u0026Aring; and operating at 40 kV and 40 mA, was employed for the analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eSEM Analysis\u003c/h2\u003e \u003cp\u003eSEM (SU1510, Hitachi, Japan) was employed to examine the surface morphology of the films. This facilitated the identification of structural interactions resulting from modifications within the film matrix. Observations were made at various magnifications to ensure a comprehensive understanding of the sample characteristics.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eTGA Analysis\u003c/h2\u003e \u003cp\u003eThe thermal stability of the films was investigated using a Shimadzu TGA-50 instrument under a nitrogen flow rate of 50 mL min\u0026thinsp;\u0026minus;\u0026thinsp;1, with a heating rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The temperature range for analysis spanned 50\u0026ndash;450\u0026deg;C.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyses\u003c/h2\u003e \u003cp\u003eAll tests were performed in triplicate, and outcomes were presented as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. All outcomes were analysed using Origin Pro 2022 (Northampton, USA). All statistical tests were two-tailed with a significance threshold at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results and discussion","content":"\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003eMoisture, Ash, and Amylose Content Analysis\u003c/h2\u003e \u003cp\u003eThe Moisture and ash content of native and modified starches are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Functionality, film formation character, texture, and stability of starch are critically dependent on moisture content. Native starch exhibits a moisture content of 12.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6, while modified starches (3, 5, \u0026amp; 8% CA) are 10.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94, 9.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17 and 10.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89. Modified starch with 5% CA had the lowest moisture content compared to native starch and other modified starches. It appears that as the CA level in the starch matrix exceeds 5%, the moisture content increases. An increase in the moisture content might be related to unreacted CA in the starch matrix. A decrease in moisture content aligns with Gautam et al. (2022), attributed to ester linkages between CA and starch. It is further supported by DHT [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], which aims to provide alternative ester bonds in the starch network. Similarly, Hong-Ju He et al. (2025) reported a decrease in moisture content in heat-moisture-treated finger millet starch, confirming the role of thermal treatments in enhancing starch stability [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Native starch exhibited an ash content of 0.0031\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60, which is higher than that of modified starches. (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), indicating improved purity and cleaner processing of the modified starch. The higher ash value in native starch may be related to elevated mineral content. A reduction in the ash content after CA/DHT may be attributed to the decomposition of mineral and organic residues, resulting in a cleaner product [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Native starch exhibits an amylose content of 15.2%, while modified starches depict an amylose content range of 16.8\u0026ndash;21.8% (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). An incremental effect of amylose content. can be connected to more efficient exposure of longer linear segments through hydrolysis and depolymerisation of the amylopectin [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. An integrated approach combining DHT and CA modification enhances the energy supplied, facilitating the structural transition of amylose from a coil to a helical form [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMoisture, ash, and amylose content of native and modified starch\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStarch Samples\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMoisture Content (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAsh Content (g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAmylose content (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNative starch\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e12.09\u0026thinsp;\u0026plusmn;\u0026thinsp;1.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.0031\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e39.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCA (3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.0059\u0026thinsp;\u0026plusmn;\u0026thinsp;1.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e40.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCA (5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e9.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.0061\u0026thinsp;\u0026plusmn;\u0026thinsp;1.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e41.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.81\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCA (8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.0062\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e41.12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003eTH Analysis\u003c/h2\u003e \u003cp\u003eTH plays a crucial role in food packaging, directly influencing key parameters such as film moisture permeability, opacity, and mechanical properties. TH values of all NFS, MFS3, MFS5, and MFS8 are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. After the CA/DHT, a slight change in TH was observed, possibly due to a disturbance in the arrangement of polymer chains within the starch matrix. Similarly, Kumar et al. (2020) suggested a decrease in film TH after CA modification of corn starch [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Unlike NFS films, MFS3, MFS5, and MFS8 exhibited a slightly higher thickness. A variation in the TH might be related to the internal rearrangement of polymeric chains in the starch matrix, which can be altered due to CA/DHT, leading to an increase in TH [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e \u003ch2\u003eMC Analysis\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents the MC values of MFS3, MFS5, MFS8, and NFS. The MC of NFS was 10.32%, higher than that of MFS3, MFS5, and MFS8. A minimum MC of 6.07% was noticed in the MFS\u003csub\u003e5\u003c/sub\u003e. MFS\u003csub\u003e8\u003c/sub\u003e shows an MC of 7.95%, higher than MFS\u003csub\u003e3\u003c/sub\u003e (6.07%). These findings are consistent with earlier research by Azevedo et al. (2015), who reported that the MC of whey protein-based films decreased after CA treatment [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Similarly, Wenhao Li et al. (2020) reported that the MC of mung bean starch decreased after repeated dry heat treatment [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The reduction in MC can be attributed to improved intra- and intermolecular interactions among the polymer chains induced during the treatments. This leads to hydrogen bonding between the functional groups (Starch-CA), decreasing the availability of free hydroxyl groups in the starch matrix and lowering MC (Kumar et al., 2020; Sandhu et al., 2020).\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section2\"\u003e \u003ch2\u003eSF Analysis\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows that the SF of MFS3, MFS5, and MFS8 was substantially lower than that of NFS (38.94%). MFS3, MFS5, and MFS8 exhibit SF values of 20.34%, 18.67%, and 21.83%, respectively. MFS5 displayed the greatest reduction, indicating the most effective restriction of water uptake. This pronounced decrease results from CA-induced esterification and DHT-mediated structural reorganization, which reinforce amylose\u0026ndash;amylopectin interactions and reduce matrix hydrophilicity. These findings are consistent with previous studies reporting suppressed swelling behaviour in citric-acid-crosslinked starch materials by Sandhu et al. (2020), who demonstrated a reduction in the SF of sorghum starch after cross-linking [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. A similar trend was observed in SF of potato starch/chitosan-based films modified with citric acid by Wu et al. (2019). Another study reported that the film's water solubility decreased after heat-moisture treatment [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Another research study suggested that CA and DHT in the starch matrix induce a cross-linked structure, reducing the availability of -OH sites on the starch matrix after modification, which may be responsible for a decrease in water interaction (Zou et al., 2021). A decrease in SF films may be attributed to the formation of a crosslinked network among starch chains during modification procedures, resulting in compact, homogeneous films with reduced SF [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec25\" class=\"Section3\"\u003e \u003ch2\u003eSI Analysis\u003c/h2\u003e \u003cp\u003eSI was measured to assess water\u0026ndash;polymer chain interactions within the starch matrix, reflecting the response of linear, branched, and double-helix starch structures (Liu et al., 2019). Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows an apparent reduction in SI for MFS3, MFS5, and MFS8 compared to NFS (51.97%). The SI values of MFSF3 and MFSF8 were markedly lower, with MFSF5 exhibiting the lowest SI (16.29%), indicating the most significant suppression of water uptake among the modified films. According to Saliu et al. (2017), the SI of the films is dependent on their compactness. This indicates that the SI of the films increased due to improved compactness following CA/DHT treatment [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Another study by Menzel et al. (2020) also reported that the SI of starch films decreased after oxidation, cross-linking, and reinforcing methods. The reduced SI results from CA/DHT-induced cross-linking and molecular tightening, which limit the number of available hydroxyl groups and restrict starch\u0026ndash;water interactions (Majzoobi et al., 2012).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFunctional properties of NFS and MFS\u003csub\u003e3\u003c/sub\u003e, MFS\u003csub\u003e5\u003c/sub\u003e, and MFS\u003csub\u003e8\u003c/sub\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFilm\u0026rsquo;s Samples\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTH (mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMC (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSI (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSF (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOp (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNFS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e0.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e10.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e51.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e38.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e31.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e10.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e20.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e21.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e23.09\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e0.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e6.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e16.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e18.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e21.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e7.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e19.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e20.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e20.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec26\" class=\"Section3\"\u003e \u003ch2\u003eOp Analysis\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows that the Op of NFS (31.03%) is substantially higher than that of the MFS3, MFS5, and MFS8. Among the modified films, MFS8 exhibits the lowest Op value of 20.06%, indicating reduced light transmission. The results clearly demonstrate that CA (3%, 5%, and 8%) with DHT progressively decreases film transparency, indicating a denser, more compact matrix structure. The results and trends of this work are consistent with those reported by Kumar (2021), which show that adding CA reduces the opacity and lightness of starch films (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In a work reported by E. Grossmann et al (2004), it was suggested that opacity in yam starch films is strongly thickness-dependent, with thicker films exhibiting greater light scattering and thus higher opacity [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. Similarly, E.R. Zavareze et al. (2012) reported that the opacity of potato starch films increased after oxidation and heat-moisture treatment [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The reduction in optical density (Op) is attributed to decreased crystallinity, which enhances light transmission through the film and consequently lowers its overall Op [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec27\" class=\"Section3\"\u003e \u003ch2\u003eMechanical Property Analysis\u003c/h2\u003e \u003cp\u003eTensile strength (TS) and elongation (E%) measurements are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The TS of the NFS was 9.24 N/mm\u0026sup2;, whereas CA/DHT modification produced a substantial enhancement, with TS values ranging from 27.00 N/mm\u0026sup2; (MFS3) to 29.82 N/mm\u0026sup2; (MFS8). MFS8 exhibited the highest strength among the modified films. Overall, CA/DHT treatment significantly improved the load-bearing capacity of the starch films. This finding is consistent with the results reported by Fern\u0026aacute;ndez-Pan et al. (2010), who observed enhanced mechanical properties in films made with chitosan at increased chitosan content and higher drying temperatures. Tapia-bl\u0026aacute;cido et al. (2013) found that amaranth flour films showed higher strength and reduced flexibility when plasticized with glycerol and processed under dry-heating conditions. Sharma et al. (2020) reported enhanced tensile strength in films prepared with Foba bean starch as the cross-linking agent. According to Narasagoudr et al. (2020), the mechanical properties of chitosan-polyvinyl alcohol films improved after heating with boswellic acid [\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec28\" class=\"Section2\"\u003e \u003ch2\u003eWVP Analysis\u003c/h2\u003e \u003cp\u003eWVP is a critical parameter in food packaging, as it governs moisture transfer between the environment and packaged products. Materials with low WVP are essential for protecting moisture-sensitive foods. As shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, CA/DHT treatment substantially improved the barrier properties of films. The WVP of NFS (3.81 \u0026times; 10⁻⁹ g s⁻\u0026sup1; m⁻\u0026sup1; Pa⁻\u0026sup1;) decreased sharply to 1.26 \u0026times; 10⁻⁹ g s⁻\u0026sup1; m⁻\u0026sup1; Pa⁻\u0026sup1; in MFS3, representing the lowest WVP among all modified films. The slightly higher WVP observed in MFS8 may be attributed to trace amounts of unreacted citric acid, which acts as a plasticizer, thereby increasing matrix permeability. These results align with earlier studies, which report that cross-linking agents reduce WVP by creating denser polymer networks and limiting moisture diffusion [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. Similarly, Mehboob et al. (2020) found that adding citric acid improved the WVP of sorghum starch films. The reduction in WVP is primarily attributed to CA/DHT-induced cross-linking, which restricts starch chain mobility and forms a denser, less permeable polymer network, thereby slowing water diffusion through the film matrix (Yang et al., 2021).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMechanical and barrier properties of NFS and MFS3, MFS5, and MFS8\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFilm\u0026rsquo;s Samples\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTS (N/mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eE (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWVP (gs\u003csup\u003e\u0026minus;1\u003c/sup\u003em\u003csup\u003e\u0026minus;1\u003c/sup\u003ePa\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e*10\u003csup\u003e\u0026minus;\u0026thinsp;9\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNFS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e9.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.514\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e28.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e3.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e27.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e21.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e1.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e29.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e22.75\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e1.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.432\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMFS8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e29.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e20.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec29\" class=\"Section2\"\u003e \u003ch2\u003eFTIR Analysis\u003c/h2\u003e \u003cp\u003eFTIR analysis was conducted to examine the changes in functional groups and molecular interactions induced by CA/DHT modification. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, all films exhibited similar spectral profiles; however, a distinct new peak at ~\u0026thinsp;1730 cm⁻\u0026sup1; appeared in MFS3, MFS5, and MFS8, confirming the formation of carbonyl groups due to citric-acid\u0026ndash;induced esterification [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The broad band at 3000\u0026ndash;3700 cm⁻\u0026sup1; corresponds to O\u0026ndash;H stretching, while the peak at ~\u0026thinsp;2930 cm⁻\u0026sup1; is attributed to C\u0026ndash;H stretching. Peaks near 1023 and 990 cm⁻\u0026sup1; represent C\u0026ndash;O stretching, and the band around 1650\u0026ndash;1640 cm⁻\u0026sup1; is associated with bound water [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Notably, modified films (MFS3, MFS5, MFS8) showed narrower peaks and slight intensity shifts, indicating reduced hydrogen bonding and structural reorganization within the starch matrix following CA/DHT treatment. A similar study was conducted by [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e], in which citric acid was added to a potato starch film.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eXRD Analysis\u003c/h3\u003e\n\u003cp\u003eThe XRD profiles (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) reveal that NFS displays a characteristic A-type diffraction pattern with peaks at 15\u0026deg;, 17.11\u0026deg;, 19.74\u0026deg;, 22.12\u0026deg;, and 23.82\u0026deg;. Notably, the MFS3, MFS5, and MFS8 retained the same crystalline pattern, indicating that the CA/DHT modification altered polymer interactions without changing the fundamental A-type crystallinity. A similar effect on XRD of sweet potato starch was noted by Hung et al. (2014) after a combination of citric acid and heat-moisture treatment. Kwon et al. (2019) also suggested that DHT and acids did not alter the XRD patterns of potato starch. The relative crystallinity of MFS3, MFS5, and MFS8 was lower than that of NFS, accompanied by a noticeable reduction in diffraction intensity after CA/DHT treatment. This indicates partial disruption of ordered regions within the starch matrix. Duyen et al. (2020) also reported a reduction in the peak intensity of mung bean starch after CA and hydrothermal treatment. A reduction in the relative crystallinity of the films after CA/DHT might be related to the fact that CA/DHT could break down starch molecules into shorter chains, facilitating the formation of double-helical chains in the starch matrix and increasing the relative crystallinity of modified starch films [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec31\" class=\"Section2\"\u003e \u003ch2\u003eSEM Analysis\u003c/h2\u003e \u003cp\u003eSEM micrographs (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) reveal that NFS possesses a generally homogeneous and continuous morphology, but exhibits minor surface defects, such as bubbles and microcracks. In contrast, the MFS3, MFS5, and MFS8 display smoother, more uniform, and highly continuous surfaces with no visible cracks or voids, indicating improved film integrity and matrix compactness following modification. Punia, Bangar, and colleagues (2021) reported enhanced surface morphology in films produced from pearl millet starch [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. Similar changes in the morphology of rice starch and rice flour films after heat and moisture treatment [\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. Another study also claimed that modification processes can enhance film morphology by promoting granule fusion and reducing granule surface pores [\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec32\" class=\"Section2\"\u003e \u003ch2\u003eTGA Analysis\u003c/h2\u003e \u003cp\u003eVariation in the thermal stability of films after CA/DHT was studied using TGA curves, as illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The decomposition stages of the films were categorised into three regions spanning from room temperature to 650\u0026deg;C. Initially, film weight loss occurred between 50 \u0026ordm;C and 250 \u0026ordm;C, likely due to the vaporization of unbound water [\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. MFS3, MFS5, and MFS8 exhibited lower weight loss (5.26%) than NFS (6.92%), indicating improved resistance to water evaporation in the former.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn the second region, weight loss for NFS reached 69.44%, whereas the modified starch film exhibited a reduced weight loss of 60.39% over the temperature range of 250\u0026deg;C to 325\u0026deg;C. A decrease in weight was related to bound water and the degradation of film-forming components [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e]. The temperatures at which weight loss occurred in the films made with MFS3, MFS5, and MFS8 were higher than in the NFS film. This suggests that a combination of CA/DHT improved thermal stability [\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec33\" class=\"Section3\"\u003e \u003ch2\u003eBiodegradability analysis\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e presents the degradation rate of MFS3, MFS5, MFS8, and NFS. A higher weight loss rate was noted in NFS samples compared to MFS3, MFS5, and MFS8. NFS samples exhibited 80% to 100% weight loss in compost, while the average weight loss in MFS3, MFS5, and MFS8 was approximately 82%. v. Similar outcomes were presented by Seligra et al. (2016), who observed that the films with high hydrophilic mass showed high biodegradability.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBiodegradable study of NFS and MFS3, MFS5, and MFS8 samples using soil and compost material.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eDegradation (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eSoil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eCompost\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNFS sample\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMFS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNFS sample\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMFS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e83.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e59.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis work presents a novel combination of physical and chemical methods to effectively modify the structural, thermal, physicochemical, and biodegradability properties of finger millet starch films. Native modified with CA/DHT produced high-quality thin films, demonstrating excellent starch\u0026ndash;CA internal network and compatibility, and yielding thin films with strong mechanical, optical, barrier, thermal, and structural properties. CA/DHT did not damage the inherent starch network but did improve molecular interactions and the amorphous region. Furthermore, the CA/DHT modification improved the films' compactness, homogeneity, and biodegradation rate, illustrating superior material performance. Our results demonstrated that a novel combination of physical and chemical methods holds potential applications in both food and non-food industries.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflict of Interest\u003c/h2\u003e \u003cp\u003eThere are no conflicts of interest among the authors\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eEthics Approval:\u003c/h2\u003e \u003cp\u003eThis study did not involve human participants or animals and therefore did not require ethical approval.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent to Participate:\u003c/strong\u003e \u003cp\u003eNot applicable, as this study did not involve human participants.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent to Publish:\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eThe Ministry of Education, India, NIT Jalandhar, and CSIR-CBRI, Roorkee, provide the fellowship, consumables, and research infra for this research work\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eNG: Conceptualization, Methodology, Investigation, Formal analysis, Data curation, Writing \u0026ndash; original draft, Visualization.SR: Methodology, Investigation, Validation, Data curation, Writing \u0026ndash; review \u0026amp; editing.RK: Supervision, Resources, Project administration, Conceptualization, Formal analysis, Writing \u0026ndash; review \u0026amp; editing.SKY: Supervision, Conceptualization, Validation, Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\u003ch2\u003eAcknowledgment\u003c/h2\u003e \u003cp\u003eThis research work is supported by the CSIR-Central Building Research Institute (CSIR-CBRI), BTKIT, Dwarahat, and the NIT Jalandhar, India, in terms of research and testing facilities.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGautam N, et al. 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Carbohydra Polym. 2016;138:66\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"discover-food","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"discoverfood","sideBox":"Learn more about [Discover Food](https://www.springer.com/44187)","snPcode":"","submissionUrl":"","title":"Discover Food","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"finger millet starch, physical \u0026 chemical modification, mechanical property, barrier property, biodegradability","lastPublishedDoi":"10.21203/rs.3.rs-8660714/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8660714/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFinger millet starch (NFS) was modified with a novel integrated citric acid (CA) (3, 5, and 8% w/w of total dry starch) and dry heat treatment (DHT) at 130 \u0026ordm;C for 5 h. Thin films were prepared from NFS, and modified starch (MFS) was prepared using a solvent casting method. The functional, thermal, and structural properties of thin films were comprehensively analysed. The thin films made with NFS exhibit a water vapour barrier of 3.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 g s⁻\u0026sup1; m⁻\u0026sup1; Pa⁻\u0026sup1;, which is significantly higher than the water vapour barrier of 1.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 g s⁻\u0026sup1; m⁻\u0026sup1; Pa⁻\u0026sup1; of the thin films with MFS. Similarly, the tensile strength of the thin film made with NFS is 9.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.514 MPa, while that of the thin film made with MFS is 29.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.229 MPa. FTIR confirms the esterification in the starch matrix at 1730 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. A smoother and more compact surface network was observed in thin films made with MFS than in NFS-based thin films. These observations suggest that the synergistic application of physical and chemical modification techniques significantly alters the functional properties of starch, thereby enhancing its suitability for food packaging applications.\u003c/p\u003e","manuscriptTitle":"Physico-Chemical Tailoring of Finger Millet Starch for Improved Barrier and Mechanical Performance","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-04 09:59:43","doi":"10.21203/rs.3.rs-8660714/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-01T04:00:22+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-14T16:24:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-08T06:51:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"315251703864200815014894527744900082329","date":"2026-03-04T10:25:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"334874026355239722449601066265484684946","date":"2026-02-27T16:41:23+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-27T08:41:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-09T16:41:52+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-05T05:29:34+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Food","date":"2026-02-05T05:15:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-food","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"discoverfood","sideBox":"Learn more about [Discover Food](https://www.springer.com/44187)","snPcode":"","submissionUrl":"","title":"Discover Food","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f0936f1e-bd05-4f19-9be1-f57476fa5f60","owner":[],"postedDate":"March 4th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-07T11:08:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-04 09:59:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8660714","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8660714","identity":"rs-8660714","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}