Effect of Domestic Cooking on Total and Individual Carotenoid Profiles of Potato

Effect of Domestic Cooking on Total and Individual Carotenoid Profiles of Potato | 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 Effect of Domestic Cooking on Total and Individual Carotenoid Profiles of Potato Jian Xu, Fankui Zeng This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4435442/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Oct, 2024 Read the published version in Potato Research → Version 1 posted 4 You are reading this latest preprint version Abstract Total and individual carotenoid concentrations were determined in raw potato tubers of 6 varieties including Kexin No. 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody, and Favorita. The relationship between color CIE L*a*b* and total carotenoid concentration, and the effect of domestic thermal treatments on the total and individual carotenoid concentrations were also investigated. The total carotenoid content in the 6 potato varieties ranged from 96.48 to 875.08 µg/100 g FW. The main carotenoids were lutein, zeaxanthin, violaxanthin, and antheraxanthin. The specific composition depended on the variety, β-carotene was not detected in all tested six potato varieties. The color value of coordinate b * was positively and significantly correlated with total carotenoid content. Boiling had the smallest effect on the decrease of total and individual carotenoids, while microwave treatment resulted with 52.67% in the highest loss of the total carotenoid in Favorita. As for the individual carotenoids, violaxanthin followed by antheraxanthin were the most heavily affected by cooking. All four thermal treatments, baking, boiling, frying and microwave decreased the carotenoid contents, boiling is recommended as a preferred method associated the lowest loss rate of total and individual carotenoids. Potato Carotenoids Variety HPLC Thermal treatment Figures Figure 1 Figure 2 Figure 3 1. Introduction Potatoes, especially yellow flesh potato contain significant content of various carotenoids (Lachman, Hamouz, & Orsák, 2016 ). Kotíková et al. ( 2016 ) found the total carotenoid content in 22 colour-fleshed potato varieties grown in the Czech Republic ranged from 35 to 722 µg/100 g FW. Van Dokkum, De Vos, & Schrijver ( 1990 ) found an average total carotenoid value of 75 µg/100 g FW. Granado, Olmedilla, Blanco, & Rojas-Hidalgo ( 1992 ) found in an early variety the major carotenoid to be lutein (12 µg/100 g FW), zeaxanthin (4 µg/100 g FW), and β -carotene (1 µg/100 g FW). Heinonen, Ollilainen, Linkola, Varo, & Koivistoinen ( 1989 ) found the major carotenoids to be lutein and zeaxanthin (13–60 µg/100 g FW) and β -carotene (3.2–7.7 µg/100 g FW). Müller ( 1997 ) found a total carotenoid content in potato tubers of 450 µg/100 g FW, which was constituted by violaxanthin (180 µg/100 g FW), antheraxanthin (130 µg/100 g FW), lutein (100 µg/100 g FW), zeaxanthin (0.16 mg/kg), neoxanthin (14 µg/100 g FW), β -carotene (5 µg/100 g FW), and β -cryptoxanthin (3 µg/100 g FW). Carotenoids are highly unsaturated structures, which makes them sensitive to light, oxygen and heat (Tian, Chen, Ye, & Chen, 2016 ). Generally, cooking will cause a decrease in the carotenoid content in potatoes, but the previous reports on various fruits and vegetables have produced a mixed results. Craft, Wise & Soares ( 1993 ) and Zhang, & Hamauzu ( 2004 ) reported a measurable decrease in carotenoid content in cooked potatoes when compared to uncooked samples, while Dietz, Sri Kantha, & Erdman ( 1988 ), Granado, Olmedilla, Blanco, & Rojas-Hidalgo ( 1992 ), and Zafrilla, Ferreres, & Tomás-Barberán ( 2001 ) reported that the carotenoid content increased after cooking. The increasing of carotenoid during heat processing can be explained by some carotenoids bonded with proteins, which are dissociated during heat cooking (Burmeister et al., 2011 ). Blessington et al. ( 2010 ) found a total carotenoid content in 8 potato genotypes of 52–170 µg lutein equivalents per 100 g FW, and domestic cooking will lead to a decreasing of total carotenoid content, however the changes of individual carotenoids were not mentioned. The results of literature analysis show that, there are few reports about the effect of thermal treatments on the individual carotenoid content in potato tubers (Kotíková et al., 2016 ). Kexin No. 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody, and Favorita are the main potato cultivation varieties in shandong province, mainly used for fresh consumption. The objectives of this study were to measure the color of potato flesh by colorimetric method, to determine total and individual carotenoid content by spectrophotometry and HPLC in these six potato varieties and to investigate the effects of domestic thermal treatments, baking, boiling, frying and microwaving on total and individual carotenoid content in two potato varieties Xisen No. 6 and Favorita, these two varieties were selected because they have yellow carotenoid-rich flesh. 2. Materials and methods 2.1. Materials Six potato varieties, Kexin 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody and Favorita were gifts from the Nation Engineering Research Center for Potato in Laoling, Shandong Province, China. The harvest time is June 15, 2017, the growth time for Kexin 1 is about 95 days, for Xisen No. 6 is about 90 days, for Atlantic is about 90 days, for Xisen No. 5 is about 90 days, for Shepody is about 100 days, and for the favorita is about 70 days. After harvest, these potato tubers were stored in ventilated clamps with electronically controlled environments, the storage temperature is 3–5 o C, and the relative humidity is 85%-95%, after six months storage, these potatoes were used for analysis. Carotenoid standards, trans -violaxanthin, trans -antheraxanthin, were purchased from ChromaDex (Irvine, CA, USA), trans -lutein, and trans -zeaxanthin, were purchased from Cayman Chemical Company (Ann Arbour, MI, USA). High-performance liquid chromatography (HPLC) grade methanol, tert-butyl methyl ether was obtained from Shanghai Aladdin Bio-chem Technology Co., Ltd (Shanghai, China). Butylated hydroxytoluene (BHT) was purchased from Tianjin Kaixin Chemical Industry Co. Ltd. (Tianjin, China). Analytical grade acetone, petroleum ether was obtained from Rionlon Bohua (Tianjin) Pharmaceutical & Chemical Co., Ltd. (Tianjin, China). 2.2. Color detection The flesh color properties of six potato varieties were evaluated in terms of the Commission Internationale de l’Eclairage (CIE) 1976 L * a * b * colorimetric method using a Color-Eye automatic differential colorimeter (X-Rite, Ci 7800). The CIE L * a * b * system was used as an important index to evaluate the color properties of potato (Seijo-Rodríguez, Escuredo, Rodríguez-Flores, & Seijo-Coello, 2018 ). L * represents color lightness ranges from 0 (black) to 100 (white), a * is the green (−) /red (+) axis, and b * is the blue (−) /yellow (+). Three to five undamaged tubers of each variety were cut in cross section, the color was detected immediately. A chromaticity diagram was generated according to the mean values of x , y by chromaticity coordinates calculation software (Version: 1.6.0.2), which contains CIE1931 2 degree field of view. 2.3. Thermal treatments Potato tubers were washed, dried, peeled and diced into ~ 6 mm cubes with a knife. Samples were thoroughly mixed and randomized ~ 50 g samples were taken for cooking. Processing times and temperatures for the four thermal treatments were based on the previous literature (Blessington et al., 2010 ) with some changes. After cooking, the carotenoids of the cooked samples were extracted immediately. 2.3.1. Baking A box-type oven (model KSL1400X, Hefei Kejing Materials Technology CO., LTD, China) was used for baking the potato cubes, samples (~ 50 g) were cooked for 15 min at 200°C. After cooking, the samples were removed from the oven and placed into a mortar and mashed with a pestle, the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction. 2.3.2. Boiling Samples (~ 50 g) were cooked for 10 min in boiling water in a 500 mL beaker with 300 mL ultrapure water, a single-linkage universal resistance furnace (Beijing Kewei Yongxing Instrument Co., LTD, China) was used as a heater to keep the water boiling. After cooking, the samples were removed from the beaker and drain off the water, mashed with mortar and pestle, the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction. 2.3.3. Frying Soybean oil was brought to 190°C in an electric fryer (model HY-871, Foshan Nanhai Bofei Mechanical and Electrical Equipment Co., Ltd., China). Potato samples (~ 50 g) were cooked for 1 min. After cooking, the samples were removed from the electric fryer, drain off the oil, mashed with mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction. 2.3.4 Microwaving Samples (~ 50 g) were cooked in a domestic microwave (model P70D20P-TD (W0), Guangdong Galanz Microwave Oven and Electrical Appliances Manufacturing Co., Ltd., China) for 2.5 min at medium baking temperature. After cooking, the samples were removed from the microwave, mashed with mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction. 2.4. Carotenoids extraction The protocol for carotenoids extraction of raw and cooked potato tubers was according to Burgos et al., ( 2009 ) with some changes. Approximately 15 g samples were mashed with a mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube, and extracted with 30 mL acetone by vortex blending for 2 min, centrifuge at 2200 rcf (Eppendorf 5810R, Hamburg, Germany) for 5 min, the pale yellow supernatant was collected. Extraction was repeated until the residue was devoid of color. Twenty mL petroleum ether was added to the mixed extracts to transfer the carotenoid by vortex blending for 5 min, the colored upper-phase (petroleum ether contains carotenoid) was separated from the acetone with a separatory funnel. An equivalent volume of 10% methanolic KOH was added to the petroleum ether phase to saponificate the carotenoid in the dark at room temperature overnight (16–20 h). BHT 0.1%, was added to the petroleum ether extract before saponification to prevent degradation of carotenoids. After saponification, the pH of the mixture solution was adjusted to 7.0 with 0.5 mol/L HCl. After ~ 30 min, the mixed solution divided into two layers, the bottom-phase was filtered through a 0.22 µm organic ultrafiltration membrane, 20 µL of the resulting saponified extracts was analyzed by HPLC. The recovery rate of the carotenoids was carried out following a previously reported method for vegetables (de Sá & Rodríguez-Amaya, 2004). 2.5. HPLC analysis After filtration, 20 µL sample solution was directly injected into the HPLC, the method used was according to Burgos et al. ( 2009 ). The analysis was performed in an Agilent 1200 Series HPLC system (Agilent Technologies, USA), equipped with G1312A pump, and photodiode array detector (model G1315D) set at 450 nm, controlled by LC 3D ChemStation software. Separation was carried out on a YMC C30 polymeric column (3 µm, 4.6 mm×250 mm), the mobile phase of the (A/B) gradient was (A) methanol and (B) tert-butyl methyl ether. The content of tert-butyl methyl ether in the solvent was increased as follows: 7% (0 min to 15 min), 10% (35 min), 40% (45 min) and maintaining this proportion for 15 min. The flow rate was 0.8 ml/min with a re-equilibration of 15 min. Identification of the carotenoids was based on the combined analysis of the retention times, co-chromatography with pure standards and the visible absorption spectra obtained by the photodiodide array detector. Quantification was done by external calibration, individual carotenoids were expressed as micrograms (µg) per 100 g fresh weight. 2.6 Statistical analysis Statistical evaluation was performed using the SPSS computer programme (SPSS Inc., Chicago, Illinois, USA). The influence of variety and thermal processing on carotenoid content was evaluated by two-way ANOVA. The loss rates of total and individual carotenoids after heat treatment were calculated by translating the data into dry base concentration. 3. Results and discussion 3.1. Potato flesh colour characteristics Color is an important quality parameter for raw potato tubers that is affected by certain pre- and postharvest factors and by the type of variety (Yang, Achaerandio, & Pujolà, 2016 ). Figure 1 shows the flesh color of the six tested potato varieties, Xisen No. 6 and Favorita had a deep yellow color, while Kexin 1, Atlantic, Xisen No. 5, and Shepody had a light yellow or cream color. Table 1 Color parameters of the six potato varieties * Vavieties L * a * b * x y Kexin No. 1 57.45 ± 3.01ab -1.27 ± 0.13d 14.56 ± 1.58a 0.3495 ± 0.0049a 0.3732 ± 0.0058a Xisen No. 6 51.42 ± 6.04a -2.62 ± 0.23b 40.12 ± 3.20c 0.4148 ± 0.0023c 0.4497 ± 0.0028c Atlantic 57.44 ± 0.99ab -1.63 ± 0.12cd 15.85 ± 0.37a 0.3512 ± 0.0012a 0.3762 ± 0.0009a Xisen No. 5 58.69 ± 2.10ab -1.48 ± 0.08d 17.40 ± 1.29a 0.3557 ± 0.0043a 0.3804 ± 0.0045a Shepody 62.93 ± 1.74b -1.94 ± 0.13c 13.91 ± 1.38a 0.3554 ± 0.0032a 0.3813 ± 0.0032a Favorita 60.33 ± 2.61b -3.24 ± 0.37a 32.08 ± 1.69b 0.3970 ± 0.0047b 0.4313 ± 0.0060b * Data are means ± standard deviation ( n = 3 for Kexin No. 1 and Xisen No. 6, n = 5 for the other varieties), each sample comprised of 3–5 tubers, the same letters within the column are not significantly different ( p >0.05), the CIE colour parameters are explained in the text. As it can be observed, the color difference of six potato varieties is mainly reflected in the b * value (Table 1 ). Xisen No. 6 and Favorita with b * values of 40.12 ± 3.20 and 32.08 ± 1.69, are significant different ( p <0.05) from the b * values of Kexin 1, Atlantic, Xisen No. 5, and Shepody. Xisen No. 6 is the most yellow potato variety observed by naked eye (Fig. 1 ), with the highest intensity b * and the lightest L * (51.42 ± 6.04). Xisen No. 6 and Favorita also can be distinguished by the value of the coordinate a *, with mean values of -2.62 ± 0.23 and − 3.24 ± 0.37, are significantly different from the other four potato varieties (p<0.05). Seijo-Rodríguez, Escuredo, Rodríguez-Flores, & Seijo-Coello ( 2018 ) measured the flesh color of 35 potato varieties with a Minolta colorimeter, and found that the yellow-fleshed potato showed significantly higher intensity b * value (35.8 ± 7.0) and the lightest L *. Figure 2 shows the color coordinates of the six potato tubers in the CIE tristimulus chromaticity diagram. The color of six potato tubers are located in the same coordinate diagram according the values of x and y listed in Table 1 . As can be seen, the locations of four potato tubers Kexin 1 (a), Atlantic (c), Xisen No. 5 (d), and Shepody (e) are close to the neutral, especially the samples Atlantic (c) and Xisen No. 5 (d) are overlapped in one point, thus, there is no big difference in the color amongst these four potato tubers. The color of the Favorita is relatively yellow than the four varieties mentioned above, Xisen No. 6 is the most yellow of the six varieties, the results were consistent with the total carotenoid content (Table 2 ). Table 2 Total and individual carotenoid concentrations by spectrophotometry and HPLC in six potato varieties Vavieties Concentration (µg 100 g − 1 fresh weight) * Total carotenoid Violaxanthin Antheraxanthin Lutein Zeaxanthin Kexin No. 1 343.96 ± 6.81 c 27.17 ± 2.56 a Tr 246.57 ± 5.41 e Nd Xisen No. 6 875.08 ± 11.71 e 344.03 ± 14.49 c 209.94 ± 5.20 b 230.84 ± 6.39 d 21.41 ± 3.02 Atlantic 230.35 ± 6.50 b 23.91 ± 1.44 a Tr 153.82 ± 1.78 c Nd Xisen No. 5 96.48 ± 0.95 a Tr Tr 75.38 ± 2.36 a Nd Shepody 222.94 ± 6.63 b 22.29 ± 1.90 a Tr 139.57 ± 2.54 b Nd Favorita 733.08 ± 7.81 d 164.66 ± 10.87 b 59.57 ± 2.78 a 231.53 ± 14.97 d Nd * Data are means ± standard deviation ( n = 3), the same letters within the column are not significantly different ( p >0.05), Tr = traces; Nd = not detectable, total carotenoid was by spectrophotometry and the individual carotenoids by HPLC. 3.2. Total and individual carotenoid concentrations Total and individual carotenoid concentrations determined in the six potato varieties were shown in Table 2 . Xisen No. 6 had the highest total carotenoid concentration of 875.08 ± 11.71 µg/100 g FW, followed by Favorita of 733.08 ± 7.81 µg/100 g FW, these two potato varieties with lutein, violaxanthin, and antheraxanthin as the principal carotenoids (Fig. 3 and Table 2 ). Previous study (Burgos et al., 2009 ) also reported that the major carotenoids in 23 potato varieties are lutein, zeaxanthin, violaxanthin, and antheraxanthin, and that the specific composition of carotenoids depends on the variety. Lutein was the predominant carotenoid in the six tested potato varieties in this study. Lutein ranging from 75.38 ± 2.36 to 246.57 ± 5.41 µg/100 g FW in Xisen No. 5 and Kexin No. 1, respectively (Table 2 ), this value is lower than the highest lutein concentration found for yellow fleshed diploid clones from S. phureja and S. stenotonum (531µg /100 g FW) (Lu, Haynes, Wiley, & Clevidence, 2001 ) but higher than that found in yellow fleshed accession 703308 varieties (211 µg/100 g FW) (Burgos et al., 2009 ). Nesterenko, & Sink ( 2003 ) measured carotenoid profiles of 19 potato genotypes and found that the major carotenoid in Atlantic is lutein (21.3 ± 1.6 µg/100 g FW), violaxanthin and antheraxanthin are very low, of 4.1 ± 0.5 µg/100 g FW and 3.9 ± 0.4 µg/100 g FW, respectively. Lutein as one of the main carotenoids in potato tubers has attracted interest, since people consuming potato varieties containing considerable lutein content may raise serum lutein concentrations which have been linked to a reduced risk for humans to be afflicted with age-related macular degeneration (AMD) (Olmedilla, Granado, Blanco, Vaquero, & Cajigal, 2001 ; Landrum & Bone, 2001 ). Except for Xisen No. 5, the other five potato varieties contain considerable violaxanthin, especially Xisen No. 6 and Favorita, of 344.03 ± 14.49 µg/100g FW and 164.66 ± 10.87 µg/100g FW respectively. Antheraxanthin was only detected in Xisen No. 6 and Favorita, with concentration of 209.94 ± 5.02 µg/100g FW and 59.57 ± 2.78 µg/100g FW respectively. These concentrations exceed those previously reported for yellow fleshed potato varieties grown in Germany (7.7–66 µg/100 g FW) (Breithaupt & Bamedi, 2002 ), but lower than that found in yellow fleshed accession 703654 varieties (376 µg/100 g FW) (Burgos et al., 2009 ). Zeaxanthin was only detected in Xisen No. 6, with a concentration of 21.41 ± 3.02 µg/100 g FW, this value is lower than 600 µg/100 g FW in yellow or deep yellow flesh potato varieties reported by Burgos et al. ( 2009 ). Another important carotenoid β-carotene was not detected in all tested six potato varieties in this study, though some previous researchers reported that β-carotene is one of the major carotenoid in potato tuber (Granado, Olmedilla, Blanco, & Rojas-Hidalgo, 1992 ; Heinonen, Ollilainen, Linkola, Varo, & Koivistoinen, 1989 ). However, Burgos et al. ( 2009 ) determined 23 potato varieties and found that β-carotene was very low or not present. Breithaupt & Bamedi ( 2002 ) also reported that white and yellow fleshed potatoes grown in Germany contain very low content of β-carotene. Some researchers even concluded that potatoes are among the most commonly consumed vegetables serve as a major source of vitamin C, not an important source of provitamin A, due to minor constituents of β-carotene (Iwanzik, Tevini, Stute, & Hilbert, 1983 ; Breithaupt & Bamedi, 2002 ). However, according to Van Eck ( 2006 ), enhancement of β-carotene content in potato tubers can be achieved by reducing β-carotene hydroxylase activity. 3.3. Relationship between potato colour and total carotenoid content The color CIE parameter b * was positively and significantly correlated with total carotenoid content, y = 8.52 + 0.033 x ( R = 0.929, p<0.001). Total carotenoid concentration was positively and significantly correlated with violaxanthin, and lutin concentrations ( R = 0.944 and 0.990, respectively, p < 0.001), which is consistent with the results of Burgos et al. ( 2009 ). 3.4. Effect of heat treatment on the carotenoid content The effect of heat treatment on the total and individual carotenoid content of two yellow potato varieties Xisen No. 6 and Favorita are listed in Table 3 . As can be seen, all four thermal treatments baking, boiling, frying and microwaving decreased the total carotenoid contents. Regardless of potato varieties, the differences of total carotenoid loss rate between the four thermal treatments are significant ( p <0.05). Table 3 Effect of cooking methods on the total and individual carotenoid concentrations * Vavieties Cooking methods Concentration (µg 100 g − 1 fresh weight) Total carotenoid Loss rate (%) Violaxanthin Loss rate (%) Antheraxanthin Loss rate (%) Lutein Loss rate (%) Zeaxanthin Loss rate (%) Xisen No. 6 Baking 759.54 ± 2.91g 13.20 253.97 ± 0.48f 26.18 169.36 ± 0.60g 19.33 215.39 ± 3.13e 6.69 19.54 ± 0.27c 8.73 Boiling 848.20 ± 0.72h 3.07 303.44 ± 6.14g 11.80 189.43 ± 0.91h 9.77 229.06 ± 3.51f 0.77 20.83 ± 0.52d 2.71 Frying 677.34 ± 4.81e 22.60 218.81 ± 2.94e 36.40 145.05 ± 2.04f 30.91 189.70 ± 2.70c 17.82 18.48 ± 0.69b 13.69 Microwaving 436.09 ± 4.83b 50.17 129.39 ± 0.53c 62.39 85.91 ± 1.65e 59.08 132.78 ± 4.65b 42.48 12.22 ± 0.38a 42.92 Favorita Baking 624.27 ± 2.86d 14.84 128.81 ± 2.38c 21.77 48.68 ± 1.04c 18.28 205.33 ± 3.01d 11.32 Nd Boiling 706.72 ± 1.92f 3.60 138.40 ± 1.15d 15.95 52.51 ± 1.12d 11.85 224.84 ± 2.58f 2.89 Nd Frying 557.12 ± 6.58c 24.00 105.51 ± 0.87b 35.92 42.67 ± 0.93b 28.37 185.06 ± 3.20c 20.07 Nd Microwaving 347.00 ± 3.25a 52.67 56.46 ± 3.45a 65.71 24.22 ± 0.47a 59.34 119.20 ± 4.67a 48.52 Nd * Data are means ± standard deviation ( n = 3), means followed by the same letters within the column are not significantly different ( p >0.05), Nd = not detectable, the calculate method of loss rate is explained in the text. Table 3 shows, boiling had the smallest effect on decreasing of total and individual carotenoids, which resulted in lose rates of total carotenoid of 3.07% and 3.60% in Xisen No. 6 and Favorita, respectively. The effect of microwaving on total and individual carotenoids decreasing was the greatest, results in loss rates of 50.17% and 52.67% in Xisen No. 6 and Favorita, respectively. These results were reversed to previous study by Blessington et al. ( 2010 ), maybe the literature applied 25 min to boil potato is too long, we found that 10 min is enough for boiling potato cubes, long time will lead to a pot of mashed potatoes. According to Blessington et al. ( 2010 ), it seems like boiling will result in the highest loss rate of total carotenoid when compared to the other three thermal treatments baking, frying and microwaving. However, the changes of individual carotenoids were not investigated in their study. Anyway, As for the individual carotenoids, violaxanthin followed by antheraxanthin are the most heavily affected by heat cooking. Microwaving leads to 62.39% and 65.71% loss rates of violaxanthin in Xisen No. 6 and Favorita, respectively, which are significantly higher than that of lutein, 42.48% and 48.52% in Xisen No. 6 and Favorita) (p<0.05). During the boiling, the loss rates of lutein were 0.77–2.89% in Xisen No. 6 and Favorita, the loss rates of violaxanthin were 11.80% and 15.95% in Xisen No. 6 and Favorita, the loss rates of antheraxanthin were 9.77% and 11.85% in Xisen No. 6 and Favorita. The same data trends can be found by the other two thermal treatments (Table 3 ). Therefore, the decreasing of lutein by domestic cooking was less when compared to other two carotenoids violaxanthin and antheraxanthin, which is in agreement with the paper of Kotíková et al. ( 2016 ). Zeaxanthin was not found in uncooked and cooked Favorita (Table 2 , Table 3 ), but according to the results of Xisen No. 6, it is safe to infer that the zeaxanthin is less affected when compared with both violaxanthin and antheraxanthin. For different plant food, the contents of individual carotenoids vary greatly after heat treatment. Zhang & Hamauzu ( 2004 ) investigated the effect of domestic cooking on the amount of individual carotenoids of broccoli, found that the content of lutein increased while the β-carotene, violaxanthin, and total carotenoids decreased after the conventional and microwave cooking. 4. Conclusions Among six potato varieties tested in this study, Xisen No. 6 followed by Favorita have the highest total carotenoid concentration. The principal carotenoids determined are lutein, violaxanthin, and antheraxanthin. β-carotene was not detected in all tested six potato varieties. The color CIE parameter b * was positively and significantly correlated with total carotenoid content. Boiling is a recommended heat treatment associated with a lower loss of nutrients. Violaxanthin followed by antheraxanthin is the most heavily affected by heat cooking. Declarations Author Information: Corresponding Author *E-mail: Fankui Zeng, [email protected] , Phone: +86-931-4968250, Fax: +86-931-8277088. Acknowledgments This work was supported by the China Agriculture Research System (Grant No. CARS-9), the Central Government Guiding Local Science and Technology Development Project in 2023 (YDZX2023029), the Gansu Planning Projects on Science and Technology (Grant No. 23CXNJ0013), and the Lanzhou planning project of science and technology (Grant No. 2023-3-39). Interest Statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References Blessington T, Nzaramba MN, Scheuring DC, Hale AL, Reddivari L (2010) Cooking methods and storage treatments of potato: effects on carotenoids, antioxidant activity, and phenolics. Am J Potato Res 87(6):479–491Jr Breithaupt D, Bamedi A (2002) Carotenoids and carotenoid esters in potatoes ( Solanum tuberosum L.): New insight into an ancient vegetable. J Agric Food Chem 50(24):7175–7181 Burgos G, Salas E, Amoros W, Auqui M, Muñoa L, Kimura M, Bonierbale M (2009) Total and individual carotenoid profiles in Solanum phureja of cultivated potatoes: I. Concentrations and relationships as determined by spectrophotometry and HPLC. J Food Compos Anal 22(6):503–508 Burmeister A, Bondiek S, Apel L, Kühne C, Hillebrand S, Fleischmann P (2011) Comparison of carotenoid and anthocyanin profiles of raw and boiled Solanum tuberosum and Solanum phureja tubers. J Food Compos Anal 24(6):865–872 Craft NE, Wise SA, Soares JH (1993) Individual carotenoid content of SRM1548 total diet and influence of storage temperature, lyophilization, and irradiation on dietary carotenoids. J Agric Food Chem 41(2):208–213 de Sá MC, Rodriguez-Amaya DB (2004) Optimization of HPLC quantification of carotenoids in cooked green vegetables—Comparison of analytical and calculated data. J Food Compos Anal 17(1):37–51 Dietz JM, Sri Kantha S, Erdman JW Jr (1988) Reversed phase HPLC analysis of α- and β-carotene from selected raw and cooked vegetables. Plant Foods Hum Nutr 38(4):333–341 Granado F, Olmedilla B, Blanco I, Rojas-Hidalgo E (1992) Carotenoid composition in raw and cooked Spanish vegetables. J Agric Food Chem 40(11):2135–2140 Heinonen MI, Ollilainen V, Linkola EK, Varo PT, Koivistoinen PE (1989) Carotenoids in Finnish foods: vegetables, fruits, and berries. J Agric Food Chem 37(3):655–659 Iwanzik W, Tevini M, Stute R, Hilbert R (1983) Carotinoidgehalt und -zusammensetzung verschiedener deutscher Kartoffelsorten und deren Bedeutung für die Fleischfarbe der Knolle. Potato Res 26(2):149–162 Kotíková Z, Šulc M, Lachman J, Pivec V, Orsák M, Hamouz K (2016) Carotenoid profile and retention in yellow-, purple- and red-fleshed potatoes after thermal processing. Food Chem 197(Part A):992–1001 Lachman J, Hamouz K, Orsák M (2016) Colored Potatoes. In: Singh J, Kaur L (eds) Advances in Potato Chemistry and Technology, 2nd edn. Academic, New York, pp 258–259 Landrum JT, Bone RA (2001) Lutein, zeaxanthin, and the macular pigment. Arch Biochem Biophys 385(1):28–40 Lu W, Haynes K, Wiley E, Clevidence B (2001) Carotenoid content and color in diploid potatoes. J Am Soc Hortic Sci 126(6):722–726 Müller H (1997) Determination of the carotenoid content in selected vegetables and fruits by HPLC and photodiode array detection. Food Res Technol 204(2):88–94 Nesterenko S, Sink K (2003) Carotenoid profiles of potato breeding lines and selected cultivars. HortScience 38(6):1173–1177 Olmedilla B, Granado F, Blanco I, Vaquero M, Cajigal C (2001) Lutein in patients with cataracts and age-related macular degeneration: A long-term supplementation study. J Sci Food Agric 81(9):904–909 Seijo-Rodríguez A, Escuredo O, Rodríguez-Flores MS, Seijo-Coello MC (2018) Assessment of antioxidant potential of potato varieties and the relationship to chemical and colorimetric measurements. Am J Potato Res 95:71–78 Tian J, Chen J, Ye X, Chen S (2016) Health benefits of the potato affected by domestic cooking: A review. Food Chem 202:165–175 Van Dokkum W, De Vos RH, Schrijver J (1990) Retinol, total carotenoids, beta-carotene, and tocopherols in total diets of male adolescents in the Netherlands. J Agric Food Chem 38(1):211–216 Van Eck J (2006) Enhancement of beta-carotene content in plants. WO 068946. Patent cooperation treaty 045640. Yang Y, Achaerandio I, Pujolà M (2016) Classification of potato cultivars to establish their processing aptitude. J Sci Food Agric 96(2):413–421 Zafrilla P, Ferreres F, Tomás-Barberán FA (2001) Effect of processing and storage on the antioxidant ellagic acid derivatives and flavonoids of red raspberry (Rubus idaeus) jams. J Agric Food Chem 49(8):3651–3655 Zhang D, Hamauzu Y (2004) Phenolics, ascorbic acid, carotenoids and antioxidant activity of broccoli and their changes during conventional and microwave cooking. Food Chem 88(4):503–509 Cite Share Download PDF Status: Published Journal Publication published 01 Oct, 2024 Read the published version in Potato Research → Version 1 posted Reviewers agreed at journal 17 Jun, 2024 Reviewers invited by journal 30 May, 2024 Editor assigned by journal 30 May, 2024 First submitted to journal 27 May, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-4435442","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":308506526,"identity":"74ae063c-59a8-4d06-a355-322c42d2b410","order_by":0,"name":"Jian Xu","email":"","orcid":"","institution":"Lanzhou Institute of Chemical Physics","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Xu","suffix":""},{"id":308506527,"identity":"1b396221-9881-41a2-9a86-34a7a53595b5","order_by":1,"name":"Fankui Zeng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIie3PvwuCUBDA8RPhtRy5viH0XxAEaYj+FiFwkuaGkKZcrDnonzkRnNRWoQbHhoY3hVNUZlv4Y2t43+Gm+8AdgEz2r61oNmHDSEouDiYx9t82gl18pfSE41FGUK190I6bdqKEuTul4owMl44SJjHwC7UTlXu2JcSLcDRVYAQmd9oJM262SSJvyMPvJsjRKqmgD1G2ajfh6NlA6aL+JdrtY+RFBzGC1BKUzHUjyKKyuvu6dugg73d4cyNQPXukii+RyWQy2c+ee24/AjijfMkAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-4660-649X","institution":"Lanzhou Institute of Chemical Physics","correspondingAuthor":true,"prefix":"","firstName":"Fankui","middleName":"","lastName":"Zeng","suffix":""}],"badges":[],"createdAt":"2024-05-17 08:52:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4435442/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4435442/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11540-024-09797-y","type":"published","date":"2024-10-01T15:57:04+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":58307712,"identity":"1aefd371-ac38-4dea-a1d9-049e18546430","added_by":"auto","created_at":"2024-06-13 18:44:23","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":28504,"visible":true,"origin":"","legend":"\u003cp\u003eDigital photographs showing the flesh colour of the six potato varieties a. Kexin No. 1; b. Xisen No. 6; c. Atlantic; d. Xisen No. 5; e. Shepody; f. Favorita.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4435442/v1/a3ad264ef938d6cc44cc471a.jpeg"},{"id":58308912,"identity":"760eedd5-c7d9-4bbd-9deb-478e597c677d","added_by":"auto","created_at":"2024-06-13 18:52:23","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":122958,"visible":true,"origin":"","legend":"\u003cp\u003eChromaticity diagram of six potato varieties a. Kexin No. 1; b. Xisen No. 6; c. Atlantic; d. Xisen No. 5; e. Shepody; f. Favorita.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4435442/v1/d80f9c53c6884286d700838e.jpeg"},{"id":58307714,"identity":"8ca81073-ae68-4649-ba66-b650f066cb0a","added_by":"auto","created_at":"2024-06-13 18:44:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":217012,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative HPLC chromatograms (processed at 450 nm) of six potato varieties. a. Kexin No. 1; b. Xisen No. 6; c. Atlantic; d. Xisen No. 5; e. Shepody; f. Favorita. Peak identification: Vio=all trans-violaxanthin, Ant=all trans-antheraxanthin, Lut=all \u003cem\u003etrans\u003c/em\u003e-lutein, Zea=all \u003cem\u003etrans\u003c/em\u003e-zeaxanthin. \u0026nbsp;chromatographic conditions are described in the text.\u003c/p\u003e","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4435442/v1/4e85fa2c26a4d57c8d9a283e.png"},{"id":66096741,"identity":"31219177-93f4-4cd0-af6d-355e3ec77464","added_by":"auto","created_at":"2024-10-07 16:08:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":984462,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4435442/v1/75c35be3-8d7c-42ab-b101-ab71fcc826f3.pdf"}],"financialInterests":"","formattedTitle":"Effect of Domestic Cooking on Total and Individual Carotenoid Profiles of Potato","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003ePotatoes, especially yellow flesh potato contain significant content of various carotenoids (Lachman, Hamouz, \u0026amp; Ors\u0026aacute;k, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Kot\u0026iacute;kov\u0026aacute; et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) found the total carotenoid content in 22 colour-fleshed potato varieties grown in the Czech Republic ranged from 35 to 722 \u0026micro;g/100 g FW. Van Dokkum, De Vos, \u0026amp; Schrijver (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1990\u003c/span\u003e) found an average total carotenoid value of 75 \u0026micro;g/100 g FW. Granado, Olmedilla, Blanco, \u0026amp; Rojas-Hidalgo (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1992\u003c/span\u003e) found in an early variety the major carotenoid to be lutein (12 \u0026micro;g/100 g FW), zeaxanthin (4 \u0026micro;g/100 g FW), and \u003cem\u003eβ\u003c/em\u003e-carotene (1 \u0026micro;g/100 g FW). Heinonen, Ollilainen, Linkola, Varo, \u0026amp; Koivistoinen (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1989\u003c/span\u003e) found the major carotenoids to be lutein and zeaxanthin (13\u0026ndash;60 \u0026micro;g/100 g FW) and \u003cem\u003eβ\u003c/em\u003e-carotene (3.2\u0026ndash;7.7 \u0026micro;g/100 g FW). M\u0026uuml;ller (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e1997\u003c/span\u003e) found a total carotenoid content in potato tubers of 450 \u0026micro;g/100 g FW, which was constituted by violaxanthin (180 \u0026micro;g/100 g FW), antheraxanthin (130 \u0026micro;g/100 g FW), lutein (100 \u0026micro;g/100 g FW), zeaxanthin (0.16 mg/kg), neoxanthin (14 \u0026micro;g/100 g FW), \u003cem\u003eβ\u003c/em\u003e-carotene (5 \u0026micro;g/100 g FW), and \u003cem\u003eβ\u003c/em\u003e-cryptoxanthin (3 \u0026micro;g/100 g FW).\u003c/p\u003e \u003cp\u003eCarotenoids are highly unsaturated structures, which makes them sensitive to light, oxygen and heat (Tian, Chen, Ye, \u0026amp; Chen, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Generally, cooking will cause a decrease in the carotenoid content in potatoes, but the previous reports on various fruits and vegetables have produced a mixed results. Craft, Wise \u0026amp; Soares (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1993\u003c/span\u003e) and Zhang, \u0026amp; Hamauzu (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2004\u003c/span\u003e) reported a measurable decrease in carotenoid content in cooked potatoes when compared to uncooked samples, while Dietz, Sri Kantha, \u0026amp; Erdman (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1988\u003c/span\u003e), Granado, Olmedilla, Blanco, \u0026amp; Rojas-Hidalgo (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1992\u003c/span\u003e), and Zafrilla, Ferreres, \u0026amp; Tom\u0026aacute;s-Barber\u0026aacute;n (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) reported that the carotenoid content increased after cooking. The increasing of carotenoid during heat processing can be explained by some carotenoids bonded with proteins, which are dissociated during heat cooking (Burmeister et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Blessington et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) found a total carotenoid content in 8 potato genotypes of 52\u0026ndash;170 \u0026micro;g lutein equivalents per 100 g FW, and domestic cooking will lead to a decreasing of total carotenoid content, however the changes of individual carotenoids were not mentioned. The results of literature analysis show that, there are few reports about the effect of thermal treatments on the individual carotenoid content in potato tubers (Kot\u0026iacute;kov\u0026aacute; et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eKexin No. 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody, and Favorita are the main potato cultivation varieties in shandong province, mainly used for fresh consumption. The objectives of this study were to measure the color of potato flesh by colorimetric method, to determine total and individual carotenoid content by spectrophotometry and HPLC in these six potato varieties and to investigate the effects of domestic thermal treatments, baking, boiling, frying and microwaving on total and individual carotenoid content in two potato varieties Xisen No. 6 and Favorita, these two varieties were selected because they have yellow carotenoid-rich flesh.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Materials\u003c/h2\u003e \u003cp\u003eSix potato varieties, Kexin 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody and Favorita were gifts from the Nation Engineering Research Center for Potato in Laoling, Shandong Province, China. The harvest time is June 15, 2017, the growth time for Kexin 1 is about 95 days, for Xisen No. 6 is about 90 days, for Atlantic is about 90 days, for Xisen No. 5 is about 90 days, for Shepody is about 100 days, and for the favorita is about 70 days. After harvest, these potato tubers were stored in ventilated clamps with electronically controlled environments, the storage temperature is 3\u0026ndash;5 \u003csup\u003eo\u003c/sup\u003eC, and the relative humidity is 85%-95%, after six months storage, these potatoes were used for analysis.\u003c/p\u003e \u003cp\u003eCarotenoid standards, \u003cem\u003etrans\u003c/em\u003e-violaxanthin, \u003cem\u003etrans\u003c/em\u003e-antheraxanthin, were purchased from ChromaDex (Irvine, CA, USA), \u003cem\u003etrans\u003c/em\u003e-lutein, and \u003cem\u003etrans\u003c/em\u003e-zeaxanthin, were purchased from Cayman Chemical Company (Ann Arbour, MI, USA). High-performance liquid chromatography (HPLC) grade methanol, tert-butyl methyl ether was obtained from Shanghai Aladdin Bio-chem Technology Co., Ltd (Shanghai, China). Butylated hydroxytoluene (BHT) was purchased from Tianjin Kaixin Chemical Industry Co. Ltd. (Tianjin, China). Analytical grade acetone, petroleum ether was obtained from Rionlon Bohua (Tianjin) Pharmaceutical \u0026amp; Chemical Co., Ltd. (Tianjin, China).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Color detection\u003c/h2\u003e \u003cp\u003eThe flesh color properties of six potato varieties were evaluated in terms of the Commission Internationale de l\u0026rsquo;Eclairage (CIE) 1976 \u003cem\u003eL\u003c/em\u003e*\u003cem\u003ea\u003c/em\u003e*\u003cem\u003eb\u003c/em\u003e* colorimetric method using a Color-Eye automatic differential colorimeter (X-Rite, Ci 7800). The CIE \u003cem\u003eL\u003c/em\u003e*\u003cem\u003ea\u003c/em\u003e*\u003cem\u003eb\u003c/em\u003e* system was used as an important index to evaluate the color properties of potato (Seijo-Rodr\u0026iacute;guez, Escuredo, Rodr\u0026iacute;guez-Flores, \u0026amp; Seijo-Coello, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). \u003cem\u003eL\u003c/em\u003e* represents color lightness ranges from 0 (black) to 100 (white), \u003cem\u003ea\u003c/em\u003e* is the green (\u0026minus;) /red (+) axis, and \u003cem\u003eb\u003c/em\u003e* is the blue (\u0026minus;) /yellow (+). Three to five undamaged tubers of each variety were cut in cross section, the color was detected immediately. A chromaticity diagram was generated according to the mean values of \u003cem\u003ex\u003c/em\u003e, \u003cem\u003ey\u003c/em\u003e by chromaticity coordinates calculation software (Version: 1.6.0.2), which contains CIE1931 2 degree field of view.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Thermal treatments\u003c/h2\u003e \u003cp\u003ePotato tubers were washed, dried, peeled and diced into ~\u0026thinsp;6 mm cubes with a knife. Samples were thoroughly mixed and randomized\u0026thinsp;~\u0026thinsp;50 g samples were taken for cooking. Processing times and temperatures for the four thermal treatments were based on the previous literature (Blessington et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) with some changes. After cooking, the carotenoids of the cooked samples were extracted immediately.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.3.1. Baking\u003c/h2\u003e \u003cp\u003eA box-type oven (model KSL1400X, Hefei Kejing Materials Technology CO., LTD, China) was used for baking the potato cubes, samples (~\u0026thinsp;50 g) were cooked for 15 min at 200\u0026deg;C. After cooking, the samples were removed from the oven and placed into a mortar and mashed with a pestle, the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.3.2. Boiling\u003c/h2\u003e \u003cp\u003eSamples (~\u0026thinsp;50 g) were cooked for 10 min in boiling water in a 500 mL beaker with 300 mL ultrapure water, a single-linkage universal resistance furnace (Beijing Kewei Yongxing Instrument Co., LTD, China) was used as a heater to keep the water boiling. After cooking, the samples were removed from the beaker and drain off the water, mashed with mortar and pestle, the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.3.3. Frying\u003c/h2\u003e \u003cp\u003eSoybean oil was brought to 190\u0026deg;C in an electric fryer (model HY-871, Foshan Nanhai Bofei Mechanical and Electrical Equipment Co., Ltd., China). Potato samples (~\u0026thinsp;50 g) were cooked for 1 min. After cooking, the samples were removed from the electric fryer, drain off the oil, mashed with mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.3.4 Microwaving\u003c/h2\u003e \u003cp\u003eSamples (~\u0026thinsp;50 g) were cooked in a domestic microwave (model P70D20P-TD (W0), Guangdong Galanz Microwave Oven and Electrical Appliances Manufacturing Co., Ltd., China) for 2.5 min at medium baking temperature. After cooking, the samples were removed from the microwave, mashed with mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube for carotenoid extraction.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Carotenoids extraction\u003c/h2\u003e \u003cp\u003eThe protocol for carotenoids extraction of raw and cooked potato tubers was according to Burgos et al., (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) with some changes. Approximately 15 g samples were mashed with a mortar and pestle, and then the homogenized tissue was transferred into a 50 mL plastic centrifuge tube, and extracted with 30 mL acetone by vortex blending for 2 min, centrifuge at 2200 rcf (Eppendorf 5810R, Hamburg, Germany) for 5 min, the pale yellow supernatant was collected. Extraction was repeated until the residue was devoid of color. Twenty mL petroleum ether was added to the mixed extracts to transfer the carotenoid by vortex blending for 5 min, the colored upper-phase (petroleum ether contains carotenoid) was separated from the acetone with a separatory funnel. An equivalent volume of 10% methanolic KOH was added to the petroleum ether phase to saponificate the carotenoid in the dark at room temperature overnight (16\u0026ndash;20 h). BHT 0.1%, was added to the petroleum ether extract before saponification to prevent degradation of carotenoids. After saponification, the pH of the mixture solution was adjusted to 7.0 with 0.5 mol/L HCl. After ~\u0026thinsp;30 min, the mixed solution divided into two layers, the bottom-phase was filtered through a 0.22 \u0026micro;m organic ultrafiltration membrane, 20 \u0026micro;L of the resulting saponified extracts was analyzed by HPLC. The recovery rate of the carotenoids was carried out following a previously reported method for vegetables (de S\u0026aacute; \u0026amp; Rodr\u0026iacute;guez-Amaya, 2004).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e2.5. HPLC analysis\u003c/h2\u003e \u003cp\u003eAfter filtration, 20 \u0026micro;L sample solution was directly injected into the HPLC, the method used was according to Burgos et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). The analysis was performed in an Agilent 1200 Series HPLC system (Agilent Technologies, USA), equipped with G1312A pump, and photodiode array detector (model G1315D) set at 450 nm, controlled by LC 3D ChemStation software. Separation was carried out on a YMC C30 polymeric column (3 \u0026micro;m, 4.6 mm\u0026times;250 mm), the mobile phase of the (A/B) gradient was (A) methanol and (B) tert-butyl methyl ether. The content of tert-butyl methyl ether in the solvent was increased as follows: 7% (0 min to 15 min), 10% (35 min), 40% (45 min) and maintaining this proportion for 15 min. The flow rate was 0.8 ml/min with a re-equilibration of 15 min. Identification of the carotenoids was based on the combined analysis of the retention times, co-chromatography with pure standards and the visible absorption spectra obtained by the photodiodide array detector. Quantification was done by external calibration, individual carotenoids were expressed as micrograms (\u0026micro;g) per 100 g fresh weight.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e2.6 Statistical analysis\u003c/h2\u003e \u003cp\u003eStatistical evaluation was performed using the SPSS computer programme (SPSS Inc., Chicago, Illinois, USA). The influence of variety and thermal processing on carotenoid content was evaluated by two-way ANOVA. The loss rates of total and individual carotenoids after heat treatment were calculated by translating the data into dry base concentration.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Potato flesh colour characteristics\u003c/h2\u003e \u003cp\u003eColor is an important quality parameter for raw potato tubers that is affected by certain pre- and postharvest factors and by the type of variety (Yang, Achaerandio, \u0026amp; Pujol\u0026agrave;, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the flesh color of the six tested potato varieties, Xisen No. 6 and Favorita had a deep yellow color, while Kexin 1, Atlantic, Xisen No. 5, and Shepody had a light yellow or cream color.\u003c/p\u003e \u003cp\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\u003eColor parameters of the six potato varieties\u003csup\u003e*\u003c/sup\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVavieties\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eL\u003c/em\u003e*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ea\u003c/em\u003e*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eb\u003c/em\u003e*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ex\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKexin No. 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.45\u0026thinsp;\u0026plusmn;\u0026thinsp;3.01ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.56\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3495\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0049a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3732\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0058a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eXisen No. 6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51.42\u0026thinsp;\u0026plusmn;\u0026thinsp;6.04a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-2.62\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40.12\u0026thinsp;\u0026plusmn;\u0026thinsp;3.20c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.4148\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0023c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4497\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0028c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtlantic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3512\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0012a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3762\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0009a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eXisen No. 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58.69\u0026thinsp;\u0026plusmn;\u0026thinsp;2.10ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3557\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0043a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3804\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0045a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShepody\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.74b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.38a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3554\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0032a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3813\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0032a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFavorita\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.61b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-3.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.08\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3970\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0047b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4313\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0060b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003e*\u003c/sup\u003e Data are means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3 for Kexin No. 1 and Xisen No. 6, \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5 for the other varieties), each sample comprised of 3\u0026ndash;5 tubers, the same letters within the column are not significantly different (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05), the CIE colour parameters are explained in the text.\u003c/p\u003e \u003cp\u003eAs it can be observed, the color difference of six potato varieties is mainly reflected in the \u003cem\u003eb\u003c/em\u003e* value (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Xisen No. 6 and Favorita with \u003cem\u003eb\u003c/em\u003e* values of 40.12\u0026thinsp;\u0026plusmn;\u0026thinsp;3.20 and 32.08\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69, are significant different (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) from the \u003cem\u003eb\u003c/em\u003e* values of Kexin 1, Atlantic, Xisen No. 5, and Shepody. Xisen No. 6 is the most yellow potato variety observed by naked eye (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), with the highest intensity \u003cem\u003eb\u003c/em\u003e* and the lightest \u003cem\u003eL\u003c/em\u003e* (51.42\u0026thinsp;\u0026plusmn;\u0026thinsp;6.04). Xisen No. 6 and Favorita also can be distinguished by the value of the coordinate \u003cem\u003ea\u003c/em\u003e*, with mean values of -2.62\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 and \u0026minus;\u0026thinsp;3.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37, are significantly different from the other four potato varieties (p\u0026lt;0.05). Seijo-Rodr\u0026iacute;guez, Escuredo, Rodr\u0026iacute;guez-Flores, \u0026amp; Seijo-Coello (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) measured the flesh color of 35 potato varieties with a Minolta colorimeter, and found that the yellow-fleshed potato showed significantly higher intensity \u003cem\u003eb\u003c/em\u003e* value (35.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.0) and the lightest \u003cem\u003eL\u003c/em\u003e*.\u003c/p\u003e \u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the color coordinates of the six potato tubers in the CIE tristimulus chromaticity diagram. The color of six potato tubers are located in the same coordinate diagram according the values of \u003cem\u003ex\u003c/em\u003e and \u003cem\u003ey\u003c/em\u003e listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. As can be seen, the locations of four potato tubers Kexin 1 (a), Atlantic (c), Xisen No. 5 (d), and Shepody (e) are close to the neutral, especially the samples Atlantic (c) and Xisen No. 5 (d) are overlapped in one point, thus, there is no big difference in the color amongst these four potato tubers. The color of the Favorita is relatively yellow than the four varieties mentioned above, Xisen No. 6 is the most yellow of the six varieties, the results were consistent with the total carotenoid content (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \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\u003eTotal and individual carotenoid concentrations by spectrophotometry and HPLC in six potato varieties\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVavieties\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eConcentration (\u0026micro;g 100 g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e fresh weight)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal carotenoid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eViolaxanthin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAntheraxanthin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLutein\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eZeaxanthin\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKexin No. 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e343.96\u0026thinsp;\u0026plusmn;\u0026thinsp;6.81 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27.17\u0026thinsp;\u0026plusmn;\u0026thinsp;2.56 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e246.57\u0026thinsp;\u0026plusmn;\u0026thinsp;5.41 e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eXisen No. 6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e875.08\u0026thinsp;\u0026plusmn;\u0026thinsp;11.71 e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e344.03\u0026thinsp;\u0026plusmn;\u0026thinsp;14.49 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e209.94\u0026thinsp;\u0026plusmn;\u0026thinsp;5.20 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e230.84\u0026thinsp;\u0026plusmn;\u0026thinsp;6.39 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e21.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtlantic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e230.35\u0026thinsp;\u0026plusmn;\u0026thinsp;6.50 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e153.82\u0026thinsp;\u0026plusmn;\u0026thinsp;1.78 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eXisen No. 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e96.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e75.38\u0026thinsp;\u0026plusmn;\u0026thinsp;2.36 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShepody\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e222.94\u0026thinsp;\u0026plusmn;\u0026thinsp;6.63 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.90 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e139.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.54 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFavorita\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e733.08\u0026thinsp;\u0026plusmn;\u0026thinsp;7.81 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e164.66\u0026thinsp;\u0026plusmn;\u0026thinsp;10.87 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e59.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.78 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e231.53\u0026thinsp;\u0026plusmn;\u0026thinsp;14.97 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003e*\u003c/sup\u003e Data are means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3), the same letters within the column are not significantly different (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05), Tr\u0026thinsp;=\u0026thinsp;traces; Nd\u0026thinsp;=\u0026thinsp;not detectable, total carotenoid was by spectrophotometry and the individual carotenoids by HPLC.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e\u003cb\u003e3.2. Total and individual carotenoid concentrations\u003c/b\u003e\u003c/h2\u003e \u003cp\u003eTotal and individual carotenoid concentrations determined in the six potato varieties were shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Xisen No. 6 had the highest total carotenoid concentration of 875.08\u0026thinsp;\u0026plusmn;\u0026thinsp;11.71 \u0026micro;g/100 g FW, followed by Favorita of 733.08\u0026thinsp;\u0026plusmn;\u0026thinsp;7.81 \u0026micro;g/100 g FW, these two potato varieties with lutein, violaxanthin, and antheraxanthin as the principal carotenoids (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Previous study (Burgos et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) also reported that the major carotenoids in 23 potato varieties are lutein, zeaxanthin, violaxanthin, and antheraxanthin, and that the specific composition of carotenoids depends on the variety.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eLutein was the predominant carotenoid in the six tested potato varieties in this study. Lutein ranging from 75.38\u0026thinsp;\u0026plusmn;\u0026thinsp;2.36 to 246.57\u0026thinsp;\u0026plusmn;\u0026thinsp;5.41 \u0026micro;g/100 g FW in Xisen No. 5 and Kexin No. 1, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), this value is lower than the highest lutein concentration found for yellow fleshed diploid clones from \u003cem\u003eS. phureja\u003c/em\u003e and \u003cem\u003eS. stenotonum\u003c/em\u003e (531\u0026micro;g /100 g FW) (Lu, Haynes, Wiley, \u0026amp; Clevidence, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) but higher than that found in yellow fleshed accession 703308 varieties (211 \u0026micro;g/100 g FW) (Burgos et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Nesterenko, \u0026amp; Sink (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2003\u003c/span\u003e) measured carotenoid profiles of 19 potato genotypes and found that the major carotenoid in Atlantic is lutein (21.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6 \u0026micro;g/100 g FW), violaxanthin and antheraxanthin are very low, of 4.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 \u0026micro;g/100 g FW and 3.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4 \u0026micro;g/100 g FW, respectively. Lutein as one of the main carotenoids in potato tubers has attracted interest, since people consuming potato varieties containing considerable lutein content may raise serum lutein concentrations which have been linked to a reduced risk for humans to be afflicted with age-related macular degeneration (AMD) (Olmedilla, Granado, Blanco, Vaquero, \u0026amp; Cajigal, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Landrum \u0026amp; Bone, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eExcept for Xisen No. 5, the other five potato varieties contain considerable violaxanthin, especially Xisen No. 6 and Favorita, of 344.03\u0026thinsp;\u0026plusmn;\u0026thinsp;14.49 \u0026micro;g/100g FW and 164.66\u0026thinsp;\u0026plusmn;\u0026thinsp;10.87 \u0026micro;g/100g FW respectively. Antheraxanthin was only detected in Xisen No. 6 and Favorita, with concentration of 209.94\u0026thinsp;\u0026plusmn;\u0026thinsp;5.02 \u0026micro;g/100g FW and 59.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.78 \u0026micro;g/100g FW respectively. These concentrations exceed those previously reported for yellow fleshed potato varieties grown in Germany (7.7\u0026ndash;66 \u0026micro;g/100 g FW) (Breithaupt \u0026amp; Bamedi, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2002\u003c/span\u003e), but lower than that found in yellow fleshed accession 703654 varieties (376 \u0026micro;g/100 g FW) (Burgos et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eZeaxanthin was only detected in Xisen No. 6, with a concentration of 21.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.02 \u0026micro;g/100 g FW, this value is lower than 600 \u0026micro;g/100 g FW in yellow or deep yellow flesh potato varieties reported by Burgos et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAnother important carotenoid β-carotene was not detected in all tested six potato varieties in this study, though some previous researchers reported that β-carotene is one of the major carotenoid in potato tuber (Granado, Olmedilla, Blanco, \u0026amp; Rojas-Hidalgo, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1992\u003c/span\u003e; Heinonen, Ollilainen, Linkola, Varo, \u0026amp; Koivistoinen, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1989\u003c/span\u003e). However, Burgos et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) determined 23 potato varieties and found that β-carotene was very low or not present. Breithaupt \u0026amp; Bamedi (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2002\u003c/span\u003e) also reported that white and yellow fleshed potatoes grown in Germany contain very low content of β-carotene. Some researchers even concluded that potatoes are among the most commonly consumed vegetables serve as a major source of vitamin C, not an important source of provitamin A, due to minor constituents of β-carotene (Iwanzik, Tevini, Stute, \u0026amp; Hilbert, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1983\u003c/span\u003e; Breithaupt \u0026amp; Bamedi, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). However, according to Van Eck (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), enhancement of β-carotene content in potato tubers can be achieved by reducing β-carotene hydroxylase activity.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Relationship between potato colour and total carotenoid content\u003c/h2\u003e \u003cp\u003eThe color CIE parameter \u003cem\u003eb\u003c/em\u003e* was positively and significantly correlated with total carotenoid content, \u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.52\u0026thinsp;+\u0026thinsp;0.033\u003cem\u003ex\u003c/em\u003e (\u003cem\u003eR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.929, p\u0026lt;0.001). Total carotenoid concentration was positively and significantly correlated with violaxanthin, and lutin concentrations (\u003cem\u003eR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.944 and 0.990, respectively, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), which is consistent with the results of Burgos et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Effect of heat treatment on the carotenoid content\u003c/h2\u003e \u003cp\u003eThe effect of heat treatment on the total and individual carotenoid content of two yellow potato varieties Xisen No. 6 and Favorita are listed in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. As can be seen, all four thermal treatments baking, boiling, frying and microwaving decreased the total carotenoid contents. Regardless of potato varieties, the differences of total carotenoid loss rate between the four thermal treatments are significant (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05).\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\u003eEffect of cooking methods on the total and individual carotenoid concentrations\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"12\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVavieties\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCooking methods\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"10\" nameend=\"c12\" namest=\"c3\"\u003e \u003cp\u003eConcentration (\u0026micro;g 100 g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e fresh weight)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal carotenoid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLoss rate (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eViolaxanthin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLoss rate (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eAntheraxanthin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eLoss rate (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eLutein\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLoss rate (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eZeaxanthin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eLoss rate (%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eXisen No. 6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBaking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e759.54\u0026thinsp;\u0026plusmn;\u0026thinsp;2.91g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e253.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e26.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e169.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.60g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e19.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e215.39\u0026thinsp;\u0026plusmn;\u0026thinsp;3.13e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e19.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e8.73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBoiling\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e848.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e303.44\u0026thinsp;\u0026plusmn;\u0026thinsp;6.14g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e189.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e229.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e20.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e2.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFrying\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e677.34\u0026thinsp;\u0026plusmn;\u0026thinsp;4.81e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e218.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.94e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e36.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e145.05\u0026thinsp;\u0026plusmn;\u0026thinsp;2.04f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e30.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e189.70\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e17.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e18.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e13.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMicrowaving\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e436.09\u0026thinsp;\u0026plusmn;\u0026thinsp;4.83b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e62.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e85.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.65e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e59.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e132.78\u0026thinsp;\u0026plusmn;\u0026thinsp;4.65b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e42.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e12.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e42.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eFavorita\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBaking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e624.27\u0026thinsp;\u0026plusmn;\u0026thinsp;2.86d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e128.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.38c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e21.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e48.68\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e18.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e205.33\u0026thinsp;\u0026plusmn;\u0026thinsp;3.01d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBoiling\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e706.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.92f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e138.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e52.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.12d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e224.84\u0026thinsp;\u0026plusmn;\u0026thinsp;2.58f\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFrying\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e557.12\u0026thinsp;\u0026plusmn;\u0026thinsp;6.58c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e105.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e35.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e42.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e28.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e185.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.20c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e20.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMicrowaving\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e347.00\u0026thinsp;\u0026plusmn;\u0026thinsp;3.25a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e56.46\u0026thinsp;\u0026plusmn;\u0026thinsp;3.45a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e65.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e24.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e59.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e119.20\u0026thinsp;\u0026plusmn;\u0026thinsp;4.67a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e48.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003e*\u003c/sup\u003e Data are means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3), means followed by the same letters within the column are not significantly different (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05), Nd\u0026thinsp;=\u0026thinsp;not detectable, the calculate method of loss rate is explained in the text.\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows, boiling had the smallest effect on decreasing of total and individual carotenoids, which resulted in lose rates of total carotenoid of 3.07% and 3.60% in Xisen No. 6 and Favorita, respectively. The effect of microwaving on total and individual carotenoids decreasing was the greatest, results in loss rates of 50.17% and 52.67% in Xisen No. 6 and Favorita, respectively. These results were reversed to previous study by Blessington et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), maybe the literature applied 25 min to boil potato is too long, we found that 10 min is enough for boiling potato cubes, long time will lead to a pot of mashed potatoes.\u003c/p\u003e \u003cp\u003eAccording to Blessington et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), it seems like boiling will result in the highest loss rate of total carotenoid when compared to the other three thermal treatments baking, frying and microwaving. However, the changes of individual carotenoids were not investigated in their study. Anyway,\u003c/p\u003e \u003cp\u003eAs for the individual carotenoids, violaxanthin followed by antheraxanthin are the most heavily affected by heat cooking. Microwaving leads to 62.39% and 65.71% loss rates of violaxanthin in Xisen No. 6 and Favorita, respectively, which are significantly higher than that of lutein, 42.48% and 48.52% in Xisen No. 6 and Favorita) (p\u0026lt;0.05). During the boiling, the loss rates of lutein were 0.77\u0026ndash;2.89% in Xisen No. 6 and Favorita, the loss rates of violaxanthin were 11.80% and 15.95% in Xisen No. 6 and Favorita, the loss rates of antheraxanthin were 9.77% and 11.85% in Xisen No. 6 and Favorita. The same data trends can be found by the other two thermal treatments (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Therefore, the decreasing of lutein by domestic cooking was less when compared to other two carotenoids violaxanthin and antheraxanthin, which is in agreement with the paper of Kot\u0026iacute;kov\u0026aacute; et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Zeaxanthin was not found in uncooked and cooked Favorita (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), but according to the results of Xisen No. 6, it is safe to infer that the zeaxanthin is less affected when compared with both violaxanthin and antheraxanthin. For different plant food, the contents of individual carotenoids vary greatly after heat treatment. Zhang \u0026amp; Hamauzu (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2004\u003c/span\u003e) investigated the effect of domestic cooking on the amount of individual carotenoids of broccoli, found that the content of lutein increased while the β-carotene, violaxanthin, and total carotenoids decreased after the conventional and microwave cooking.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eAmong six potato varieties tested in this study, Xisen No. 6 followed by Favorita have the highest total carotenoid concentration. The principal carotenoids determined are lutein, violaxanthin, and antheraxanthin. β-carotene was not detected in all tested six potato varieties. The color CIE parameter \u003cem\u003eb\u003c/em\u003e* was positively and significantly correlated with total carotenoid content. Boiling is a recommended heat treatment associated with a lower loss of nutrients. Violaxanthin followed by antheraxanthin is the most heavily affected by heat cooking.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Information:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorresponding Author\u003c/p\u003e\n\u003cp\u003e*E-mail:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFankui Zeng, [email protected], Phone: +86-931-4968250, Fax: +86-931-8277088.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the China Agriculture Research System (Grant No. CARS-9), the Central Government Guiding Local Science and Technology Development Project in 2023 (YDZX2023029), the Gansu Planning Projects on Science and Technology (Grant No. 23CXNJ0013), and the Lanzhou planning project of science and technology (Grant No. 2023-3-39).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInterest Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBlessington T, Nzaramba MN, Scheuring DC, Hale AL, Reddivari L (2010) Cooking methods and storage treatments of potato: effects on carotenoids, antioxidant activity, and phenolics. Am J Potato Res 87(6):479\u0026ndash;491Jr\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBreithaupt D, Bamedi A (2002) Carotenoids and carotenoid esters in potatoes (\u003cem\u003eSolanum tuberosum\u003c/em\u003e L.): New insight into an ancient vegetable. J Agric Food Chem 50(24):7175\u0026ndash;7181\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurgos G, Salas E, Amoros W, Auqui M, Mu\u0026ntilde;oa L, Kimura M, Bonierbale M (2009) Total and individual carotenoid profiles in \u003cem\u003eSolanum phureja\u003c/em\u003e of cultivated potatoes: I. Concentrations and relationships as determined by spectrophotometry and HPLC. J Food Compos Anal 22(6):503\u0026ndash;508\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurmeister A, Bondiek S, Apel L, K\u0026uuml;hne C, Hillebrand S, Fleischmann P (2011) Comparison of carotenoid and anthocyanin profiles of raw and boiled Solanum tuberosum and Solanum phureja tubers. J Food Compos Anal 24(6):865\u0026ndash;872\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCraft NE, Wise SA, Soares JH (1993) Individual carotenoid content of SRM1548 total diet and influence of storage temperature, lyophilization, and irradiation on dietary carotenoids. J Agric Food Chem 41(2):208\u0026ndash;213\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede S\u0026aacute; MC, Rodriguez-Amaya DB (2004) Optimization of HPLC quantification of carotenoids in cooked green vegetables\u0026mdash;Comparison of analytical and calculated data. J Food Compos Anal 17(1):37\u0026ndash;51\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDietz JM, Sri Kantha S, Erdman JW Jr (1988) Reversed phase HPLC analysis of α- and β-carotene from selected raw and cooked vegetables. Plant Foods Hum Nutr 38(4):333\u0026ndash;341\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGranado F, Olmedilla B, Blanco I, Rojas-Hidalgo E (1992) Carotenoid composition in raw and cooked Spanish vegetables. J Agric Food Chem 40(11):2135\u0026ndash;2140\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHeinonen MI, Ollilainen V, Linkola EK, Varo PT, Koivistoinen PE (1989) Carotenoids in Finnish foods: vegetables, fruits, and berries. J Agric Food Chem 37(3):655\u0026ndash;659\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIwanzik W, Tevini M, Stute R, Hilbert R (1983) Carotinoidgehalt und -zusammensetzung verschiedener deutscher Kartoffelsorten und deren Bedeutung f\u0026uuml;r die Fleischfarbe der Knolle. Potato Res 26(2):149\u0026ndash;162\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKot\u0026iacute;kov\u0026aacute; Z, Šulc M, Lachman J, Pivec V, Ors\u0026aacute;k M, Hamouz K (2016) Carotenoid profile and retention in yellow-, purple- and red-fleshed potatoes after thermal processing. Food Chem 197(Part A):992\u0026ndash;1001\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLachman J, Hamouz K, Ors\u0026aacute;k M (2016) Colored Potatoes. In: Singh J, Kaur L (eds) Advances in Potato Chemistry and Technology, 2nd edn. Academic, New York, pp 258\u0026ndash;259\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLandrum JT, Bone RA (2001) Lutein, zeaxanthin, and the macular pigment. Arch Biochem Biophys 385(1):28\u0026ndash;40\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu W, Haynes K, Wiley E, Clevidence B (2001) Carotenoid content and color in diploid potatoes. J Am Soc Hortic Sci 126(6):722\u0026ndash;726\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM\u0026uuml;ller H (1997) Determination of the carotenoid content in selected vegetables and fruits by HPLC and photodiode array detection. Food Res Technol 204(2):88\u0026ndash;94\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNesterenko S, Sink K (2003) Carotenoid profiles of potato breeding lines and selected cultivars. HortScience 38(6):1173\u0026ndash;1177\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOlmedilla B, Granado F, Blanco I, Vaquero M, Cajigal C (2001) Lutein in patients with cataracts and age-related macular degeneration: A long-term supplementation study. J Sci Food Agric 81(9):904\u0026ndash;909\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSeijo-Rodr\u0026iacute;guez A, Escuredo O, Rodr\u0026iacute;guez-Flores MS, Seijo-Coello MC (2018) Assessment of antioxidant potential of potato varieties and the relationship to chemical and colorimetric measurements. Am J Potato Res 95:71\u0026ndash;78\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTian J, Chen J, Ye X, Chen S (2016) Health benefits of the potato affected by domestic cooking: A review. Food Chem 202:165\u0026ndash;175\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Dokkum W, De Vos RH, Schrijver J (1990) Retinol, total carotenoids, beta-carotene, and tocopherols in total diets of male adolescents in the Netherlands. J Agric Food Chem 38(1):211\u0026ndash;216\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Eck J (2006) Enhancement of beta-carotene content in plants. WO 068946. Patent cooperation treaty 045640.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang Y, Achaerandio I, Pujol\u0026agrave; M (2016) Classification of potato cultivars to establish their processing aptitude. J Sci Food Agric 96(2):413\u0026ndash;421\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZafrilla P, Ferreres F, Tom\u0026aacute;s-Barber\u0026aacute;n FA (2001) Effect of processing and storage on the antioxidant ellagic acid derivatives and flavonoids of red raspberry (Rubus idaeus) jams. J Agric Food Chem 49(8):3651\u0026ndash;3655\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang D, Hamauzu Y (2004) Phenolics, ascorbic acid, carotenoids and antioxidant activity of broccoli and their changes during conventional and microwave cooking. Food Chem 88(4):503\u0026ndash;509\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":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"potato-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"potr","sideBox":"Learn more about [Potato Research](http://link.springer.com/journal/11540)","snPcode":"11540","submissionUrl":"https://www.editorialmanager.com/potr/default2.aspx","title":"Potato Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Potato, Carotenoids, Variety, HPLC, Thermal treatment","lastPublishedDoi":"10.21203/rs.3.rs-4435442/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4435442/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTotal and individual carotenoid concentrations were determined in raw potato tubers of 6 varieties including Kexin No. 1, Xisen No. 6, Atlantic, Xisen No. 5, Shepody, and Favorita. The relationship between color CIE \u003cem\u003eL*a*b*\u003c/em\u003e and total carotenoid concentration, and the effect of domestic thermal treatments on the total and individual carotenoid concentrations were also investigated. The total carotenoid content in the 6 potato varieties ranged from 96.48 to 875.08 \u0026micro;g/100 g FW. The main carotenoids were lutein, zeaxanthin, violaxanthin, and antheraxanthin. The specific composition depended on the variety, β-carotene was not detected in all tested six potato varieties. The color value of coordinate \u003cem\u003eb\u003c/em\u003e* was positively and significantly correlated with total carotenoid content. Boiling had the smallest effect on the decrease of total and individual carotenoids, while microwave treatment resulted with 52.67% in the highest loss of the total carotenoid in Favorita. As for the individual carotenoids, violaxanthin followed by antheraxanthin were the most heavily affected by cooking. All four thermal treatments, baking, boiling, frying and microwave decreased the carotenoid contents, boiling is recommended as a preferred method associated the lowest loss rate of total and individual carotenoids.\u003c/p\u003e","manuscriptTitle":"Effect of Domestic Cooking on Total and Individual Carotenoid Profiles of Potato","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-13 18:44:19","doi":"10.21203/rs.3.rs-4435442/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-06-17T13:34:14+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-05-30T06:31:20+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-05-30T04:19:55+00:00","index":"","fulltext":""},{"type":"submitted","content":"Potato Research","date":"2024-05-27T21:14:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"potato-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"potr","sideBox":"Learn more about [Potato Research](http://link.springer.com/journal/11540)","snPcode":"11540","submissionUrl":"https://www.editorialmanager.com/potr/default2.aspx","title":"Potato Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"0b24867b-edef-4cd7-9e0c-a8ccc391429d","owner":[],"postedDate":"June 13th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-07T15:59:46+00:00","versionOfRecord":{"articleIdentity":"rs-4435442","link":"https://doi.org/10.1007/s11540-024-09797-y","journal":{"identity":"potato-research","isVorOnly":false,"title":"Potato Research"},"publishedOn":"2024-10-01 15:57:04","publishedOnDateReadable":"October 1st, 2024"},"versionCreatedAt":"2024-06-13 18:44:19","video":"","vorDoi":"10.1007/s11540-024-09797-y","vorDoiUrl":"https://doi.org/10.1007/s11540-024-09797-y","workflowStages":[]},"version":"v1","identity":"rs-4435442","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4435442","identity":"rs-4435442","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}