The foaming properties of sweet potato protein hydrolysates produced by Alcalase and Ficin

BACKGROUND: The processing of sweet potatoes generates a waste by-product rich in sweet potato protein (SPP). OBJECTIVE: In this study, the effects of the concentrations of Alcalase and Ficin, hydrolysis time and pH value on the foaming properties of SPP hydrolysates (SPPHs) determined via gas sparging method were investigated. RESULTS: The results showed that SPPH prepared by Alcalase exhibited a significantly higher foaming expansion (the highest of 576%) than that of the SPP (462%) but displayed a weaker liquid volume stability compared with SPPH hydrolyzed by Ficin. The molecular weight of SPPH prepared by Alcalase was distributed in 10-30 kDa. A good microbiological quality of the SPPH prepared by Alcalase in pH 13 has been confirmed, and it is suitable for food application with respect to its microbiological safety profile. CONCLUSIONS: SPPH (pH 13) could be further safely applied in food, especially as a food additive at low concentrations to create a better organic plant-based foaming agent for the food industry. (c) 2023 Society of Chemical Industry.