Yang Yaqin, Jin Haobo, Chen Bao, Zhang Yuanyuan, Cai Zhaoxia, Sheng Long
National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518000, China.
National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Food Chem. 2025 Mar 15;468:142516. doi: 10.1016/j.foodchem.2024.142516. Epub 2024 Dec 16.
This study explored the impact of varying alkalinity levels in pH-shifting treatments on egg yolk protein (EYP) emulsification and investigated the underlying oil-water interface adsorption mechanism. Increasing alkaline pH-shifting treatment exposed more hydrophobic groups within EYP, altering its tertiary structure. Moreover, pH-shifting treatment reduced solution particle size (P < 0.05), possibly by disintegrating insoluble egg yolk granules (EYG) into smaller subunits. Under pH 12.0-shifting conditions, egg yolk (EY) solution reached minimum turbidity and maximum solubility (81.62 %). During initial adsorption, pH 9.0-shifting solution exhibited maximum diffusion rate (0.049 mN/m/s), correlated with minimum solution particle size (88.36 nm). Subsequently, alkaline pH-shifting induced protein rearrangement at the oil-water interface, leading to maximum interfacial pressure (21.01 mN/m) and viscoelastic modulus (44.55 mN/m) under pH 12.0-shifting conditions. This increased emulsion stability by 23.82 % with the lowest creaming index (21.82 %). These findings were crucial for enhancing EYP utilization and promoting EY as a food emulsifier.
本研究探讨了pH值转变处理中不同碱度水平对蛋黄蛋白（EYP）乳化作用的影响，并研究了其潜在的油水界面吸附机制。增加碱性pH值转变处理会使EYP中更多的疏水基团暴露出来，改变其三级结构。此外，pH值转变处理降低了溶液颗粒大小（P < 0.05），这可能是通过将不溶性蛋黄颗粒（EYG）分解成更小的亚基来实现的。在pH 12.0转变条件下，蛋黄（EY）溶液达到最低浊度和最大溶解度（81.62%）。在初始吸附过程中，pH 9.0转变溶液表现出最大扩散速率（0.049 mN/m/s），这与最小溶液颗粒大小（88.36 nm）相关。随后，碱性pH值转变在油水界面诱导蛋白质重排，在pH 12.0转变条件下导致最大界面压力（21.01 mN/m）和粘弹性模量（44.55 mN/m）。这使乳液稳定性提高了23.82%，且具有最低的乳析指数（21.82%）。这些发现对于提高EYP利用率和促进EY作为食品乳化剂具有重要意义。
