离子强度对菜籽分离蛋白气液界面行为及泡沫特性的影响  

Effects of Ionic Strength on Gas-Liquid Interface Behavior and Foam Characteristics of Rapeseed Protein Isolate

作　　者：王梅 姚轶俊 刘昆仑[2] 熊文飞 王立峰 Wang Mei;Yao Yijun;Liu Kunlun;Xiong Wenfei;Wang Lifeng(Collaborative Innovation Center for Modern Grain Circulation and Safety,College of Food Science and Engineering,Nanjing University of Finance and Economics,Nanjing 210023;College of cereals,oils and foodstuffs,Henan University of Technology,Zhengzhou 450001)

机构地区：[1]南京财经大学食品科学与工程学院,江苏省现代粮食流通与安全协同创新中心,南京210023 [2]河南工业大学粮油食品学院,郑州450001

出　　处：《中国粮油学报》2021年第3期28-34,共7页Journal of the Chinese Cereals and Oils Association

基　　金：国家重点研发计划(2016YFD0401401);南京市科技计划(201716034);江苏省研究生科研与实践创新计划(KYCX18_1406)。

摘　　要：来源于菜籽油饼粕的蛋白质氨基酸平衡性好、生物效价高,具有较高的营养价值,是近年来受到普遍关注的优质蛋白资源。采用动态滴形分析和荧光光谱法,分析了在pH值为7时,不同的离子强度下,气液界面压力的变化情况以及蛋白质微环境的变化。实验表明:表面压力π小于10 mN/m时扩散控制吸附动力学,扩散速率随着离子强度的增大而加快;表面压力π大于10 mN/m时,展开和重排机制控制吸附动力学,展开和重排速率受到离子强度的影响,与离子强度成正比。随着离子强度的增大,菜籽分离蛋白的起泡性逐渐增大;在离子强度大于50 mmol/L时,会导致菜籽蛋白的分子结构柔性下降,导致了菜籽分离蛋白溶液的泡沫稳定性降低。荧光光谱分析表明随着离子强度的增加,菜籽蛋白分子先发生聚集,而后又逐渐展开。The protein derived from rapeseed oil meal has good amino acid balance,high biological titer and high nutritional value.It is a high-quality protein resource that has caused public concernin recent years.Therefore,dynamic droplet analysis and fluorescence spectroscopy were used to analyze the changes of gas-liquid interface pressure and protein microenvironment at the pH value of 7 under different ionic strengths.The results showed that diffusion controled adsorption kinetics when the surface pressureπwas less than 10 mN/m,and the diffusion rate was accelerated with the increase of ionic strength;the expansion and rearrangement mechanisms controled the adsorption kinetics,and the expansion and rearrangement rate was affected by the ionic strength,which was directly proportional to the ionic strength when the surface pressureπwas greater than 10 mN/m.With the increase of ionic strength,the foaming property of rapeseed protein gradually increased;when the ionic strength was greater than 50 mmol/L,the molecular structure of rapeseed protein would decrease,resulting in reduced foam stability of the rapeseed protein isolate solution.Fluorescence analysis showed that as the ionic strength increased,the conformation of rapeseed protein first agglomerated,and then gradually expanded.

关 键 词：菜籽分离蛋白 离子强度 气液界面吸附动力学 泡沫特性 

分 类 号：TS201.2[轻工技术与工程—食品科学]