• 基础研究 •

制备方法对乳清分离蛋白-绿原酸共价接枝物结构和功能性质的影响

1. （1.成都大学食品与生物工程学院，四川 成都 610106；2.浙江大学生物系统工程与食品科学学院，浙江 杭州 310058）
• 出版日期:2021-07-15 发布日期:2021-07-27
• 基金资助:
四川省科技厅重点研发项目（2019YFN0174；2019YFN0172）；肉类加工四川省重点实验室开放基金项目（20-R-05）

Effect of Preparation Methods on the Structural and Functional Properties of Whey Protein Isolate-Chlorogenic Acid Conjugates

CHEN Weijun, LIU Donghong, LI Yuncheng, MENG Fanbing, LIU Dayu

1. (1. School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China;2. College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China）
• Online:2021-07-15 Published:2021-07-27

Abstract: Objective: To evaluate the effect of preparation methods on the structural and functional properties of whey protein isolate (WPI)-chlorogenic acid (CA) conjugates. Methods: The methods tested were an alkali method, a free radical method and an enzymatic method. The reactive group content, CA amount of covalent binding, molecular structure, surface hydrophobicity, thermal stability, antioxidant activity and emulsion properties of WPI-CA conjugates were analyzed. Results: Free amino groups, tryptophan and sulfhydryl groups all participated in the grafting reaction with free amino group being the major reactive group. The CA amounts of covalent binding of the conjugates prepared by the alkali, free radical and enzymatic methods were (52.70 ± 1.81), (42.57 ± 1.85), and (63.75 ± 2.50) μmol/g, respectively. The conjugates showed less α-helix relative content, higher random coil relative content and lower fluorescence intensity than WPI. Covalent bonding of CA induced by the alkali and enzymatic methods decreased the surface hydrophobicity and increased the thermal stability of WPI, while the free radical method led to the opposite results. The emulsion properties and antioxidant activity of the conjugates were higher than that of WPI, and the antioxidant activity was positively proportional to the amount of bonded CA. Conclusion: The highest grafting efficiency was obtained by the enzymatic method, and the prepared conjugates showed best thermal stability and antioxidant activity. This study can provide a reference for the preparation and application of protein-polyphenol conjugates as antioxidant carrier materials.