Xu Ruolin, Gao Qing, Li Junhua, Su Yujie, Gu Luping, Yang Yanjun, Chang Cuihua
School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Food Res Int. 2024 Dec;198:115325. doi: 10.1016/j.foodres.2024.115325. Epub 2024 Nov 13.
This study aims to clarify the difference between phospholipase A1 (PLA1) and phospholipase A2 (PLA2) in terms of hydrolyzing egg yolk (EY). The results indicated that the disintegration of the lipoprotein micelle structure after phospholipase hydrolysis induced an enhanced solubility of proteins. The solubility after PLA1 and PLA2 treatment (91.36 %/83.49 %) was significantly higher than that of the untreated egg yolk (27.89 %). Simultaneously, the disintegration of the lipoprotein micelle structure induced structural unfolding of proteins with hydrophobic chains buried inside the spatial structure, while charged amino acids and hydrophilic chains exposed on the surface. This structural deformation contributed to the increased thermal stability of EY, thereby increasing intermolecular electrostatic repulsion. In comparison, PLA1 hydrolyzed EY showed relatively better thermal stability than PLA2, due to the lower surface hydrophobicity. However, PLA2 hydrolyzed EY (up to 225 mL) had greatly higher emulsifying capacity than PLA1 (up to 159 mL), due to the better stability and emulsifying ability of the generated 1-lyso-phospholipase. Furthermore, we discovered that proteins and phospholipids jointly functioned at the interface to influence the particle size and stability of emulsions. Specifically, the emulsifying activity of phospholipids may play a more decisive role in determining the particle size, while the interfacial adsorption of proteins or protein particles may be more crucial in ensuring the stability of the emulsions. These findings had significant implications for the application and advancement of phospholipase-catalyzed egg yolk hydrolysis, providing practical guidance for the production of EY with high thermal stability or emulsifying capacity.
本研究旨在阐明磷脂酶A1（PLA1）和磷脂酶A2（PLA2）在水解蛋黄（EY）方面的差异。结果表明，磷脂酶水解后脂蛋白胶束结构的解体导致蛋白质溶解度增强。PLA1和PLA2处理后的溶解度（91.36%/83.49%）显著高于未处理的蛋黄（27.89%）。同时，脂蛋白胶束结构的解体导致蛋白质结构展开，疏水链埋在空间结构内部，而带电荷的氨基酸和亲水链暴露在表面。这种结构变形有助于提高蛋黄的热稳定性，从而增加分子间的静电排斥力。相比之下，由于表面疏水性较低，PLA1水解的蛋黄表现出比PLA2相对更好的热稳定性。然而，由于生成的1-溶血磷脂酶具有更好的稳定性和乳化能力，PLA2水解的蛋黄（高达225 mL）的乳化能力比PLA1（高达159 mL）高得多。此外，我们发现蛋白质和磷脂在界面处共同发挥作用，影响乳液的粒径和稳定性。具体而言，磷脂的乳化活性在决定粒径方面可能起更决定性的作用，而蛋白质或蛋白质颗粒的界面吸附在确保乳液稳定性方面可能更为关键。这些发现对磷脂酶催化蛋黄水解的应用和进展具有重要意义，为生产具有高热稳定性或乳化能力的蛋黄提供了实际指导。
