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91.
鲜核桃仁因易于褐变而难以作为成品生产与销售。本实验以‘香玲’核桃湿鲜坚果为试材,分别对新鲜核桃仁、已褐变核桃仁进行不同工艺参数下4 种方法抑制褐变以及2 种方法脱色处理,根据20 ℃货架期下色值变化和感官观测结果,选取两组实验的最佳处理条件分别为1.0%(质量分数,后同)抗坏血酸(ascorbic acid,AsA)+0.05%柠檬酸(citric acid,CA)浸泡5 min(抑制褐变)以及1.0% AsA 20 ℃下浸泡1 h(脱色)。分别用两种方法单独处理或与1 kJ/m2短波紫外线(ultraviolet radiation C,UVC)复合处理,以同等条件下去离子水处理为对照组,统一用30 μm厚的聚乙烯袋包装,5 ℃货架保鲜。结果表明,两组实验中,单独处理和UVC复合处理均可持续抑制多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)活力升高,苯丙氨酸解氨酶(phenylalanine ammonia lyase,PAL)活力在货架14~21 d时较对照组显著提高(P<0.05),第56天时抑制褐变的单一和复合处理组及脱色的复合处理组酸价均显著低于对照组(P<0.05)。两组实验中复合处理可同时延缓细菌和霉菌的滋生,部分提高总抗氧化活性(ferric reducing/antioxidant power,FRAP);核桃仁过氧化值(peroxide value,POV)有所增加,含油率未受明显影响,1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力与对照组差异不明显。核桃仁种衣和去皮核桃仁的PPO活力均受AsA的竞争性抑制。5 ℃货架56 d时,脱色组复合处理核桃仁的亮度(L*值)达到与抑制褐变处理同等效果,且核桃仁无可见霉变。本研究结果可为鲜核桃仁的商品化生产提供理论与技术依据。 相似文献
92.
七种日韩梨果泥贮藏稳定性研究 总被引:1,自引:0,他引:1
以丰水、华山、南水、大果水晶、圆黄、黄金、新高梨为原料,通过检测梨泥的pH值、还原糖、氨基态氮、5-羟甲基糠醛(5-HMF)、可溶性酚和总色差的含量,对7种日韩梨果泥贮藏稳定性进行研究。结果表明:在贮藏过程中,7种梨泥贮藏稳定性由高到低依次为圆黄、华山、大果水晶、丰水、南水、新高和黄金。圆黄梨泥的还原糖(9.6%~7.2%)和氨基态氮(4.2~3.5mg/100mL)含量较高,5-HMF(0.6~1.1mg/100g)和可溶性酚(3.3~2.1mg/g)含量较少,pH值(3.3~3.4)和色差值(22.7~39.9)较低,贮藏稳定性优于其他品种。 相似文献
93.
The effectiveness of ozone and acidulant treatments in extending the refrigerated shelf life of fresh-cut potatoes 总被引:1,自引:0,他引:1
Calder BL Skonberg DI Davis-Dentici K Hughes BH Bolton JC 《Journal of food science》2011,76(8):S492-S498
Abstract: The objective of the study was to determine the effectiveness of acidulant dip treatments (with or without aqueous ozone) to reduce enzymatic browning and to extend the shelf life of fresh‐cut potato slices during refrigerated storage (4 °C) for 28 d. Potato slices subjected to aqueous ozone (2 ppm) had significantly (P≤ 0.05) higher L‐values and lower a‐values, but ozone did not appear to have any effect on aerobic plate counts (APCs) or polyphenol oxidase (PPO) activity. NatureSeal (NS) and sodium acid sulfate (SAS) were the most effective acidulant treatments in reducing browning (significantly [P≤ 0.05] higher L‐values, lower a‐values, and browning index values) regardless of ozone treatment. NS and SAS also had lower PPO activity compared to other treatments on days 0 and 28, and significantly (P≤ 0.05) lower APCs (≤2.00 log CFU/g) over refrigerated storage. Therefore, the SAS treatment was comparable to NS, a commercially available product, and showed promise as an effective antibrowning dip to reduce browning and spoilage in fresh‐cut potato products. Practical Application: A 1% SAS dip treatment which included 1% citric and 1% ascorbic acid was found to be an effective antibrowning dip for fresh‐cut potatoes along with NatureSeal®'s PS‐10, compared to other treatments. They were both effective in maintaining low microbial counts over refrigerated storage. Additionally, aqueous ozone washes (2 ppm) showed significant benefits to reduce browning; however, ozone did not affect microbial counts or PPO enzyme activity. Therefore, the SAS treatment could have potential use in the fruit and vegetable industry to reduce browning and spoilage in fresh‐cut potato products. 相似文献
94.
温度对软包装葡萄酒总酚和氧化褐变的影响 总被引:1,自引:0,他引:1
在不同温度条件下对红葡萄酒进行储存实验,运用福林-酚比色法测定不同温度条件下葡萄酒中总酚含量,同时检测葡萄酒褐变度的变化规律,研究分析温度对红葡萄酒氧化褐变及其氧化褐变速率的影响。研究发现,温度越高,葡萄酒总酚减少越快,氧化褐变度也越大。研究将为红葡萄酒储存和包装研究提供理论基础。 相似文献
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Jiao Zhang Junjie Li Ayesha Murtaza Aamir Iqbal Lijuan Zhu Shinawar Waseem Ali Muhammad Usman Roshan Yameen Siyi Pan Wanfeng Hu 《International Journal of Food Science & Technology》2022,57(2):963-973
This work evaluated the synergistic effects of combined high-intensity ultrasound (HIU) with β-cyclodextrin (β-CD) treatments on inhibiting browning of apple juice and explored the mechanism through simulation system. The combined treatment of 300 W HIU with 0.006 g mL−1 β-CD had a synergistic impact on maintaining juice colour, resulting in a 39.06% reduction in browning degree, only a 36.64% decrease in total phenolic content, and a 17.82% reduction in PPO activity. The inhibition of enzymatic browning in simulated system revealed that HIU suppressed the enzyme (Polyphenol oxidase, PPO) and β-CD inhibited enzyme (PPO) and embedded substrate (polyphenol). The results of spectroscopic analysis showed that the particle-size distribution of PPO narrowed, the content of α-helix in the secondary structure increased, the fluorescence intensity increased, and the maximum wavelength was red-shifted after HIU and β-CD treatment. Changes in structure could further result in PPO activity loss. Hence, the combined treatment could synthetically alleviate the browning of apple juice. 相似文献
98.
Sneh Punia Bangar Monica Trif Fatih Ozogul Manoj Kumar Vandana Chaudhary Milan Vukic Maharishi Tomar Sushil Changan 《Comprehensive Reviews in Food Science and Food Safety》2022,21(2):1958-1978
According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented. 相似文献
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