摘要
以脱脂火麻仁粉(defatted hemp seed meal,HPM)为原料,采用两种方法进行火麻仁蛋白(hemp seed protein isolate,HPI)的提取分离,碱提/酸沉法制备得到碱提蛋白(hemp seed protein isolate-alkaline extraction,HPI-AE),盐溶/盐析法制备得到盐提蛋白(hemp seed protein isolate-salt extraction,HPI-SE)。HPI-SE的蛋白含量(94.8%)高于HPI-AE的蛋白含量(85.9%);并且HPI-SE的外观色泽更加亮白。蛋白质凝胶电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)结果表明,两种方法提取的火麻仁蛋白主要成分均为火麻仁球蛋白,二者氨基酸组成相似,均含有丰富的精氨酸。不同pH值条件下,HPI的溶解性曲线均呈U型,但是在相同pH值条件下,二者的溶解性存在较大的差异。火麻仁蛋白的起泡性和蛋白质的溶解性呈现出正相关,当pH值远离等电点时,同种电荷的静电斥力提高了蛋白质的溶解性,从而改善了蛋白质的起泡性。荧光光谱显示,在不同pH值条件下,HPI的蛋白构象不随pH值变化发生明显改变,但HPI-SE的荧光强度高于HPI-AE的荧光强度,显示HPI-SE的蛋白质聚集程度高于HPI-AE。
Hemp seed protein isolate(HPI)from defatted hemp seed meal(HPM)were prepared using the methods of alkaline extraction/acid precipitation(HPI-AE)and salt extraction/salt precipitation(HPI-SE).The protein content of HPI-SE(94.8%)was higher than that of HPI-AE(85.9%).The sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)indicated that the main component of HPI was hemp seed globulin,both of which had similar amino acid composition and were rich in arginine.The solubility curves of HPI were U-shaped under different pH conditions,however,there was a difference in solubility of HPI under the same pH condition.The foaming ability of HPI was positively related to the solubility of the protein.When the pH value was away from the isoelectric point,the electrostatic repulsion increased the solubility of the HPI,thereby the foaming ability of the HPI was improved.The fluorescence spectrum indicated that the conformation of HPI did not change significantly with the change of pH,but the fluorescence intensity of HPI-SE was higher than that of HPI-AE,showing that the protein aggregation degree of HPI-SE was higher than that of HPI-AE.
作者
徐鹏伟
刘家宁
常森林
王晓东
常坦然
于朝晖
赵庆生
赵兵
XU Peng-wei;LIU Jia-ning;CHANG Sen-lin;WANG Xiao-dong;CHANG Tan-ran;YU Zhao-hui;ZHAO Qing-sheng;ZHAO Bing(National Key Laboratory of Biochemical Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Yunnan Hanmeng Pharmaceutical Co.,Ltd.,Kunming 650000,Yunnan,China)
出处
《食品研究与开发》
CAS
北大核心
2021年第3期97-104,共8页
Food Research and Development
关键词
火麻
火麻仁蛋白
提取
理化性质
功能性
hemp
hemp seed protein
extraction
physicochemical property
functional property
