抗坏血酸/过氧化氢介导乳清分离蛋白与EGCG接枝聚合动力学  

Kinetics of Ascorbic Acid/Hydrogen Peroxide-mediated Graft Polymerization of Whey Protein Isolate with EGCG

作　　者：熊厚盛 陈立莹 解新安[1] 李雁[1] 李璐[1] XIONG Housheng;CHEN Liying;XIE Xin’an;LI Yan;LI Lu(College of Food Science,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学食品学院,广东广州510642

出　　处：《现代食品科技》2023年第6期53-60,共8页Modern Food Science and Technology

基　　金：国家自然科学基金项目(31501471)。

摘　　要：以抗坏血酸(Ascorbic Acid,Asc)和过氧化氢(Hydrogen Peroxide,H_(2)O_(2))为引发剂,研究乳清分离蛋白(Whey Isolate Protein,WPI)与表没食子儿茶素没食子酸酯((-)-Epigallocatechin Gallate,EGCG)接枝聚合动力学。系统研究活化时间、引发剂浓度、单体浓度和温度对接枝量的影响,通过测定反应级数和表观活化能,建立接枝反应动力学方程。结果表明,在Asc/H_(2)O_(2)体系中,由抗坏血酸自由基(Asc^(-)·)介导WPI与EGCG接枝反应。当反应条件为Asc浓度0.014mol/L,H_(2)O_(2)浓度0.10mol/L,溶液pH值6,温度308.15K以及活化时间120min时,接枝量为42.08mg/g。基于上述结果,我们可以得到在Asc浓度0.01~0.022mol/L,H_(2)O_(2)浓度0.09~0.12mol/L,EGCG浓度0.0012~0.0042mol/L,温度298.15~308.15K变化范围内,建立了WPI接枝EGCG的聚合速率方程,聚合反应的表观活化能E=12.96kJ/mol。研究结果为蛋白质的结构设计和可控制备提供理论指导,拓宽蛋白质在食品工业中的应用。Graft polymerization of(-)-epigallocatechin gallate(EGCG)onto whey protein isolate(WPI)was investigated using ascorbic acid(Asc)and hydrogen peroxide(H_(2)O_(2))as a redox system.The effects of different reaction parameters on the graft yield;activation time,initiator concentration,monomer concentration,and temperature were determined,and the kinetic equation for the graft polymerization reaction was established from the reaction level and apparent activation energy.The results demonstrated that,in an Asc/H_(2)O_(2) system,acid free radicals(Asc^(-)·)mediate the graft polymerization of WPI and EGCG,with the graft yield reaching 42.08 mg/g under an ascorbic acid concentration of 0.014 mol/L,H_(2)O_(2) concentration of 0.10 mol/L,pH value 6,temperature of 35,and activation time of 120 min.Based on the above results,a℃calculation equation describing the WPI-EGCG polymerization rate was obtained for reactions under an Asc concentration range of 0.01~0.022 mol/L,H_(2)O_(2) concentration range of 0.09~0.12 mol/L,EGCG concentration of 0.0012~0.0042 mol/L,and temperature of 298.15~308.15 K.An activation energy of 12.96 kJ/mol was obtained for polymerization.The results provide theoretical guidance for the structural design and controllable preparation of proteins,thus broadening the application of proteins in the food industry.

关 键 词：抗坏血酸 过氧化氢 乳清分离蛋白 表没食子儿茶素没食子酸酯 聚合动力学 

分 类 号：TS201.2[轻工技术与工程—食品科学]