Abstract: 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 SDSPAGE 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.

Key words: potato protein, isolation, functional properties