摘要
通过测定大豆分离蛋白的粒径分布、溶解性、乳化性、三级结构及热稳定性等,分析探讨了低压均质处理(0～40 MPa)对大豆分离蛋白的溶解性及其结构的影响。结果显示,低压均质处理能够降低大豆分离蛋白的粒径,显著改善溶解性,并且溶解度与乳化活性指数、乳化稳定性指数呈正相关;得到了溶解度与乳化活性指数、乳化稳定性指数的线性拟合模型函数,其相关系数分别为0. 956 8和0. 962 5。荧光光谱分析表明,随着均质压力的增大,大豆分离蛋白结构展开,最大吸收波长红移,内部色氨酸基团暴露,荧光强度增大; 30 MPa时,荧光强度最大,均质压力进一步增大时,由于蛋白分子发生聚集,之前暴露的活性基团内卷,导致荧光强度略有降低。热稳定性的分析结果验证了上述结论。
High pressure homogenization is one of the most common physical modification methods in protein processing.However,the pressure of homogenization generally does not exceed 40 MPa in actual production due to the limitation of equipment.Therefore,it is of great importance to study the effect of low pressure homogenization(0~40 MPa)on the solubility and structure of soybean protein isolate.The effects of low-pressure homogenization(0~40 MPa)on the solubility and structure of soybean protein isolate(SPI)were studied by measuring particle size distribution,solubility,emulsification,tertiary structure and thermal stability.The results showed that low-pressure homogenization treatment could reduce the particle size of SPI,significantly improve the solubility,and the solubility was positively correlated with emulsifying ability and emulsifying stability.The linear fitting model functions were obtained,and the correlation coefficients were 0.956 8 and 0.962 5,respectively.Fluorescence spectrum analysis showed that the structure of SPI was expanded with the increase of homogeneous pressure,the maximum absorption wavelength was red-shifted,the internal tryptophan group was exposed,and the fluorescence intensity was increased with the increase of homogeneous pressure.At 30 MPa,the fluorescence intensity was the highest.When homogeneous pressure was further increased,the protein molecules were aggregated,and the former exposed active groups were hided in the inside of SPI with a slight decrease in fluorescence intensity due to inward crimping of active groups.The above results were verified by the analysis results of thermal stability.
作者
李杨
李明达
张毅方
江连洲
王中江
滕飞
LI Yang;LI Mingda;ZHANG Yifang;JIANG Lianzhou;WANG Zhongjiang;TENG Fei(College of Food Science, Northeast Agricultural University, Harbin 150030, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第3期345-351,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金面上项目(31671807)
关键词
大豆分离蛋白
低压均质
乳化性
溶解性
soybean protein isolate
low pressure homogenization
emulsification
solubility
