College of Food Science and Engineering , Nanjing University of Finance and Economics/Key Laboratory of Grains and Oils Quality Control and Processing, Collaborative Innovation Center for Modern Grain Circulation and Safety , Nanjing 210023 , China.
J Agric Food Chem. 2019 Apr 10;67(14):4023-4030. doi: 10.1021/acs.jafc.8b06898. Epub 2019 Apr 1.
Protein hydrolysates, as surfactants, can scavenge radicals, but their poor distributions at the oil-water interface limit their storage stability. Therefore, we studied covalent interaction between rice protein hydrolysates and chlorogenic acid under alkaline conditions to improve the physical and oxidative stability of oil-in-water emulsions. Turbidity and particle size measurements demonstrated the formation of hydrolysates-chlorogenic acid complexes, and their covalent interaction resulted in the decrease and redshift of the fluorescence intensity. The emulsifying activity of the hydrolysates could be effectively improved after the covalent interaction with 0.025% chlorogenic acid. The modified emulsions possessed a notable physical stability according to the least changes in size (0.08 μm) and ζ-potential (3.34 mV) of the emulsion ( P > 0.05). Moreover, the covalent interaction endowed modified emulsions with high oxidative stability to effectively inhibit lipid oxidative deterioration during storage. The adsorption of hydrolysates to the emulsion interface was increased by the adequate addition of chlorogenic acid, which resulted in the oil droplet being surrounded by a thicker interfacial film. The covalent interaction between the protein hydrolysates and chlorogenic acid could be used to construct natural emulsion systems with a higher physical and oxidative stability during storage.
蛋白质水解物作为表面活性剂可以清除自由基，但它们在油水界面的分布不佳限制了其储存稳定性。因此，我们研究了在碱性条件下米蛋白水解物与绿原酸之间的共价相互作用，以提高水包油乳液的物理和氧化稳定性。浊度和粒径测量表明形成了水解物-绿原酸复合物，其共价相互作用导致荧光强度降低和红移。与 0.025%绿原酸共价相互作用后，水解物的乳化活性可以得到有效提高。经修饰的乳液具有显著的物理稳定性，乳液的粒径（0.08μm）和ζ-电位（3.34mV）变化最小（P＞0.05）。此外，共价相互作用赋予修饰乳液高氧化稳定性，可有效抑制储存过程中脂质的氧化劣变。绿原酸的适量添加增加了水解物在乳液界面的吸附，导致油滴被更厚的界面膜包围。蛋白质水解物与绿原酸之间的共价相互作用可用于构建具有更高物理和氧化稳定性的天然乳液体系，在储存过程中。
