预加热处理对甘薯蛋白乳化特性的影响  

Effects of Pre-heat Treatment on Emulsifying Properties of Sweet Potato Protein

作　　者：费扬 张吴昊 霍艳荣[1] 李永新 杨虎清[1] 陈刚[1] Fei Yang;Zhang Wuhao;Huo Yanrong;Li Yongxin;Yang Huqing;Chen Gang(School of Food and Health,Zhejiang A&F University,Lin an311300)

机构地区：[1]浙江农林大学食品与健康学院,临安311300

出　　处：《中国粮油学报》2023年第5期88-95,共8页Journal of the Chinese Cereals and Oils Association

基　　金：国家自然科学基金项目(31871857);国家现代农业产业技术体系资助项目(CARS-10)。

摘　　要：为探究预加热处理对甘薯蛋白乳化特性的影响,本研究以预加热处理(90℃)后的甘薯蛋白制备蛋白乳液,对蛋白乳化稳定性指数(ESI)、蛋白乳化活性指数(EAI)、乳液液滴粒径、Zeta电位和流变学特性进行测定。采用远紫外圆二色光谱法表征甘薯蛋白经预加热处理后的二级结构变化。随着预加热处理时间延长至10 min,ESI值提高约80%,Zeta电位绝对值增大约50%,EAI值降低约30%,乳液液滴粒径下降约20%;稳态流变学结果表明乳液表观黏度逐渐增大;动态流变学结果表明乳液结构强度逐步增强;远紫外圆二色光谱实验表明,预加热处理后甘薯蛋白的α-螺旋、β-折叠含量下降,而β-转角、无规则卷曲含量有所上升。研究结果表明,适度时间预加热处理(5~10 min,90℃)能改善甘薯蛋白的乳化稳定性,但会弱化乳化活性,归因于甘薯蛋白结构的改变以及蛋白表面净电荷的改变,为预加热处理调控蛋白乳液特性提供参考。In order to explore the effect of pre-heat treatment on emulsifying properties of sweet potato protein(SPP),in this study,the SPP after pre-heat treatment(90℃)was used to prepare emulsion.The emulsifying stability index(ESI),emulsifying activity index(EAI),droplet size,Zeta potential and rheological properties were measured.The change of secondary structure of SPP after pre-heat treatment was evaluated by far-UV circular dichroism(CD).With the prolongation of pre-heat treatment time to 10 min,the ESI value increased by about 80%,the absolute value of Zeta potential enhanced by about 50%.In contrast,the EAI value decreased by about 30%and the emulsion droplet size declined by about 20%.With the increase of pre-heat treatment time,the steady rheological results indicated that the apparent viscosity increased gradually,and the dynamic rheological results indicated that the strength of the network structure of the emulsions was enhanced.The results of far-UV CD revealed that the contents ofα-helix andβ-Sheet of SPP decreased,whileβ-turn and random coil increased after pre-heat treatment.The results revealed that moderate time pre-heat treatment(5~10 min,90℃)enabled to improve the emulsifying stability of SPP,but weaken the emulsifying activity,which might have contributed to the changes of secondary structure and the net surface charge of SPP.This study provided an available reference for pre-heat treatment in regulating the characteristics of protein emulsion.

关 键 词：甘薯蛋白 预加热处理 乳化稳定性 乳化活性 蛋白结构 

分 类 号：TS201.7[轻工技术与工程—食品科学]