Yu Pengjuan, Yan Jiayan, Kong Lingru, Yu Juan, Zhao Xinxin, Peng Xinyan
College of Life Sciences, Yantai University, Yantai 264005, China.
College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Foods. 2023 Aug 21;12(16):3135. doi: 10.3390/foods12163135.
Whey protein hydrolysate (WPH) has made a breakthrough in inhibiting oxidative deterioration and improving the quality of meat products during storage. Based on our previous study of extracting the most antioxidant active fraction I (FI, the molecular weight < 1 kDa) from whey protein hydrolysates of different molecular weights, the present study continued to delve into the effects of WPH with fraction I on the structure and function of myofibrillar proteins (MP) in ground pork during the freeze-thaw (F-T) cycles. With the number of F-T cycles raised, the total sulfhydryl content, the relative contents of α-helix, Ca-ATPase activity, K-ATPase activity, solubility, emulsion activity index (EAI), and emulsion stability index (ESI) of MP gradually decreased. Conversely, the carbonyl content and the relative content of random curl showed an increasing trend. In particular, the damage to the structure and the function of MP became more pronounced after three F-T cycles. But, during F-T cycles, FI stabilized the structure of MP. Compared to the control group, the 10% FI group showed a remarkable improvement ( < 0.05) in the total sulfhydryl content, Ca-ATPase activity, K-ATPase activity, solubility, EAI and ESI after multiple F-T cycles, suggesting that 10% FI could effectively inhibit protein oxidation and had the influence of preserving MP function properties. In conclusion, WPH with fraction I can be used as a potential natural antioxidant peptide for maintaining the quality of frozen processed meat products.
乳清蛋白水解物（WPH）在抑制氧化变质和改善肉类产品储存期间的品质方面取得了突破。基于我们之前从不同分子量的乳清蛋白水解物中提取抗氧化活性最高的组分I（FI，分子量<1 kDa）的研究，本研究继续深入探讨含组分I的WPH对绞碎猪肉中肌原纤维蛋白（MP）在冻融（F-T）循环过程中的结构和功能的影响。随着F-T循环次数的增加，MP的总巯基含量、α-螺旋相对含量、Ca-ATP酶活性、K-ATP酶活性、溶解度、乳化活性指数（EAI）和乳化稳定性指数（ESI）逐渐降低。相反，羰基含量和无规卷曲相对含量呈上升趋势。特别是，经过三次F-T循环后，MP的结构和功能损伤变得更加明显。但是，在F-T循环过程中，FI稳定了MP的结构。与对照组相比，10% FI组在多次F-T循环后的总巯基含量、Ca-ATP酶活性、K-ATP酶活性、溶解度、EAI和ESI有显著改善（<0.05），表明10% FI能有效抑制蛋白质氧化并对保持MP功能特性有影响。总之，含组分I的WPH可作为一种潜在的天然抗氧化肽用于维持冷冻加工肉类产品的品质。
