Conformational study of kiwi fruit (Actinidia chinensis Planch.) seed protein isolates by fluorescence spectroscopy

Abstract

Kiwi fruit (Actinidia chinensis Planch.) seeds protein isolates (KSPI), a potential source of edible protein, are produced as solid wastes in food industry and remain underutilized yet. Kiwi fruit seed protein isolates had more proteins or peptides with low molecular weights, showing a better digestibility and the proportion of essential amino acids were better than that recommended by FAO/WHO. Fluorescence spectroscopy was used to investigate the conformational changes of KSPI with different environmental conditions including pH values, temperatures and denaturants. The conformation of KSPI changed significantly at pH 5 and the fluorescence intensity decreased greatly as the temperature increased. The denatured extent of the denaturants was sodium dodecyl sulfate (SDS) > urea > guanidine hydrochloride. These results provide theoretical basis for food manufacturing and indicate that KSPI as a potential ingredient could be used as a substitute for soy protein in food industries.