醋蛋乳化液制备过程中蛋白质理化性质的变化

Changes in Physicochemical Properties of Protein in Vinegar-egg Emulsion Processing

该研究以鸡蛋为原料,分别以蛋醋质量比1:1、1:2、1:3、1:4的比例添加米醋,制备功能性醋蛋乳化液。为研究醋蛋乳化液中米醋对蛋液蛋白结构的作用,对鸡蛋蛋白水解程度、蛋白分子量分布、蛋白颗粒大小、蛋白质二级结构以及变性温度进行分析。当蛋醋比1:4,浸泡72h后,水解度达到最大为12.82%±0.51%(p<0.05)。其中溶菌酶、卵黄高磷蛋白、IgY、低密度脂蛋白在米醋中不易分解,卵转铁蛋白、卵白蛋白、卵粘蛋白及亚基、高密度脂蛋白降解更为明显。同时,米醋处理的鸡蛋蛋白α-螺旋、β-折叠减少,β-转角增多,蛋白二级结构趋于无序状态。并且蛋白粒径尺寸减小,由单峰变为双峰甚至三峰。而相较于蛋液,醋蛋乳化液热变性温度均有所升高,体系热稳定性升高。综上,米醋在水解鸡蛋蛋白的过程中可产生多种多肽和寡肽,改变蛋白质的结构与性质。该研究可为醋蛋乳化液的品质特性研究和应用产品开发提供参考。

Eggs were added to rice vinegar emulsion(egg vinegar quality ratio 1:1,1:2,1:3,1:4),to prepare functional vinegar-egg emulsion.The degree of egg protein hydrolysis,protein molecular weight distribution,protein particle size,protein secondary structure,and denaturation temperature were analyzed during the hydrolysis.Results showed that the ratio of egg to vinegar 1:4,the degree of hydrolysis reached a maximum of 12.82%±0.51%(p<0.05)after soaking for 72 h.Lysozyme,yolk high-phosphorus protein,IgY and low-density lipoprotein were not easy to decompose in rice vinegar.But the degradation of egg transferrin,ovalbumin,egg mucin and subunit,and high-density lipoprotein were very obvious.Treated by the rice vinegar,theα-helix andβ-sheet of the egg protein decreased,and theβ-turn increased,showing that the secondary structure of the protein was disordered.And the protein particle size of egg was lowered,the particle size distribution changed from a single peak to a double peak or even a triple peak.Compared to the egg liquid,the heat denaturation temperature of the vinegar-egg emulsion was increased,it meant that the thermal stability was increased.In summary,eggs hydrolyzed by rice vinegar produced a large number of peptides and small molecule oligopeptides,the structure and properties of proteins were changed.This study provides a reference for the study of quality characteristics and products of vinegar-egg emulsion.