超声预处理对酪蛋白酸钠-EGCG相互作用及其复合物抗氧化活性的影响  

Effects of Ultrasound Pretreatment on Sodium Caseinate-EGCG Interactions and the Antioxidant Activity of Their Complexes

作　　者：陈卫军 朱巧岚 汪海洋 刘东红[2] CHEN Weijun;ZHU Qiaolan;WANG Haiyang;LIU Donghong(College of Food and Biological Engineering,Chengdu University,Chengdu 610106,China;School of Biosystems Engineering and Food Science,Zhejiang University,Hangzhou 310058,China)

机构地区：[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　　处：《食品工业科技》2024年第21期30-36,共7页Science and Technology of Food Industry

基　　金：四川省自然科学基金(2022NSFSC1617,2022NSFSC1764)。

摘　　要：采用荧光分光光度计、紫外分光光度计等研究了超声预处理对酪蛋白酸钠-表没食子儿茶素没食子酸酯((-)-epigallocatechin-3-gallate,EGCG)相互作用及其复合物抗氧化活性的影响,并从蛋白质结构变化上探究了其作用机理。结果表明:EGCG对酪蛋白酸钠内源荧光的淬灭形式为静态淬灭。超声预处理后酪蛋白酸钠同EGCG之间的结合常数由9.51×10^(3) L·(mol/L)^(-1)提高至7.48×10^(4) L·(mol/L)^(-1),结合位点数由0.871提高至1.067,分别提高了7.87倍和22.50%,说明二者结合能力增强。同酪蛋白酸钠相比,超声预处理酪蛋白酸钠无规卷曲含量增加,内源荧光强度和表面疏水性指数增强,结构的改变促进了其同EGCG的结合。酪蛋白酸钠-EGCG复合物的形成可以抑制EGCG的降解、提高其抗氧化稳定性,而超声预处理能增强复合物的这一作用。The interaction between sodium caseinate and(-)-epigallocatechin-3-gallate(EGCG)and the antioxidant activity of their complexes as influenced by ultrasound pretreatment were studied by a fluorescence spectrophotometer and an ultraviolet spectrophotometer,and its mechanism was also investigated base on the changes in protein structure.The results showed that the quenching of the endogenous fluorescence of sodium casein induced by EGCG was a static nature.With ultrasound pretreatment,the apparent binding constant between sodium caseinate and EGCG increased from 9.51×10^(3) L·(mol/L)-1 to 7.48×10^(4) L·(mol/L)-1 and the number of binding sites between sodium caseinate and EGCG increased from 0.871 to 1.067,indicating an increase of 7.87 times and 22.50%,respectively.The results revealed that ultrasound pretreatment could enhance the binding capacity of sodium caseinate for EGCG.Compared with sodium caseinate,ultrasound pretreated sodium caseinate showed higher random coil content,fluorescence intensity and surface hydrophobicity.These ultrasound-induced conformational changes promoted the binding between sodium casein and EGCG.Complexing with sodium caseinate could inhibit the degradation of EGCG and improve its antioxidant stability,and better protection was obtained by complexing EGCG with ultrasound pretreated sodium caseinate.

关 键 词：酪蛋白酸钠 表没食子儿茶素没食子酸酯 超声 相互作用 抗氧化活性 

分 类 号：TS201.2[轻工技术与工程—食品科学]