Effects of Enzyme Species on Physicochemical,Structural and Emulsifying Properties of Soybean Meal Hydrolysates

Li Haiyan; Liu Zhuo

doi:10.14083/j.issn.1001-4942.2025.11.011

Abstract：To study the influence of enzyme species on physicochemical,structural and emulsifying prop-erties of soybean meal hydrolysates(SMH),the alkaline protease,neutral protease,papain and flavor prote-ase were selected for the enzymatic hydrolysis of soybean meal in this study.The physicochemical properties of SMH were explored by determining moisture,protein,fat,reducing sugar content and solubility;the structure properties of SMH was characterized by determining the hydrolysis degree,surface hydrophobicity,Fourier transform infrared spectroscopy(FT-IR),and intrinsic fluorescence spectroscopy;finally,the emulsifying properties of SMH were characterized by using emulsifying activity index and emulsifying stability index.The results showed that compared with soybean meal,SMH showed significantly higher protein,fat,reducing sugar content and solubility,and the SMH obtained with alkaline protease had the highest solubility(97.73%)and higher protein content(61.50%).In addition,the β-sheet and β-turn contents of the soybean meal decreased significantly after enzymatic hydrolysis,while the content of the random coil increased.The intrinsic fluores-cence spectra showed that the maximum absorption wavelength of SMH was red-shifted and the fluorescence in-tensity reduced obviously,and the hydrophobicity of the surface increased significantly.The above results indi-cated that the structure of soybean meal changed after enzymatic hydrolysis,which consequently promoted the changes of physicochemical and emulsifying properties.The hydrolysis degree of alkaline protease was the highest with the lowest α-helix content(17.54%)and the highest random coil content(20.31%)of its SMH.The flavor protease enhanced the surface hydrophobicity of soybean meal to the greatest extent,and the emulsi-fying properties of its SMH were the best.In conclusion,the structure and properties of soybean meal were sig-nificantly improved by enzymatic hydrolysis,which could provide some theoretical references for the applica-tion of soybean meal in food processing.