马铃薯蛋白组分的分离提取和功能性质研究

Isolation and Characterization of Potato Protein Fractions

采用透析与等电点沉淀相结合的工艺方法提取分离马铃薯块茎蛋白组分;并对其理化性质和功能性质进行检测。结果显示:此提取工艺流程合理易行,马铃薯块茎酸性蛋白组分和碱性蛋白组分的得率分别为0.535%、0.741%;纯度分别为92.5%、89.2%;酸性蛋白组分沉降系数5S,分子质量82kD;碱性性蛋白组分沉降系数8S,分子质量140kD。SDS-PAGE电泳图谱表明5S蛋白组分有1条亚基带;8S蛋白组分有4条亚基带。5S蛋白组分的表面疏水性、吸油能力、乳化性显著高于8S蛋白组分;而8S蛋白组分的总巯基含量以及起泡性高于5S蛋白组分。马铃薯蛋白组分可以作为功能食品的蛋白添加原料。

Potato protein fractions was isolated by combing dialysis and isoelectric precipitation, and their partial physicochemical and functional properties were determined. The results showed that the isolation procedure was feasible, with the acid and alkaline protein fraction of potato tuber accounting for 0.535% and 0.741%, respectively, and their purity were 92.5% and 89.2%, respectively. The acid protein fraction＇ s sedimentation coefficient was 5S, consisting principally of one subunit band with apparent Mw 41 kD. The alkline protein fraction＇s sedimentation coefficient was 8S, with 4 subunit bands detected in the SDS- PAGE pattern, and apparent Mw 25, 23, 22 kD and 16 kD, respectively. The 5S fraction showed greater surface hydrophobicity, fat absorption, and emulsifying capacity, while lower sulfhydryl content, foaming capacity. The 8S fraction showed greater sulfhydryl content and foaming capacity than 5S fraction. The protein fractions of potato were the best choice for functional foods.