Comparative study of physicochemical and structural properties of plant proteins hydrolyzed by different

Abstract

This study used trypsin to hydrolyze soybean protein isolate (SPI), Cyperus esculentus protein (CEP), Wheat gluten protein (WGP), and flaxseed protein (FP) to varying extents, comparing the structure and physicochemical properties of four plant proteins as well as their enzymatic hydrolysates. Results indicate SPI's surface hydrophobicity rises with hydrolysis, whereas CEP's decreases. Additionally, all four plant proteins exhibit improved essential amino acid content and oil-holding capacity as hydrolysis progresses. The CEP with a 20% degree of hydrolysis achieved the optimal oil holding capacity, reaching 10.2 g/g. SPI demonstrated superior foam capacity. As the degree of hydrolysis increased, foam stability varied among the four proteins. The CEP hydrolyzed to 10% exhibited the highest emulsifying activity index, achiving a value of 60 m²/g. Additionally, the emulsifying stability index of CEP hydrolysates significantly improved as the degree of hydrolysis increased. According to the DPPH• assay, both CEP and their enzymatic hydrolysate had the highest free radical scavenging rate. These findings provided a theoretical basis and empirical evidence for the use and adaptation of plant protein hydrolysates as a promising and environmentally sustainable source of plant-derived peptides in food processing reaprocessing.