Effects of limited enzymolysis and glycosylation on emulsifying properties of soybean protein isolates

Abstract

Objective: This study aimed to develop novel soybean protein isolate （SPI）-based emulsifiers. Methods: The structure of SPI was modified by limited enzymolysis combined with glycosylation and the effects of this synergistic modification on the emulsification characteristics of SPI was studied. Results: Among the different components obtained from the SPI hydrolysate （SPIH）, the high molecular mass component （F30） exhibited the best emulsifying property. The emulsifying stability of F30-dextran conjugates obtained for 4 h was the best. Compared with SPI, SPIH and F30, the F30-dextran conjugates stabilized emulsions showed the lowest initial average particle size and the best storage stability. When the pH was close to the isoelectric point of SPI or the system was at a high salt concentration, all emulsions were unstable to cause aggregation. Compared with SPI, both SPIH and F30 stabilized emulsions had a higher aggregation degree. However, F30-dextran conjugates provided additional steric hindrance and hydrophilicity due to covalently bound dextran, which exhibited a higher resistance under adverse environmental conditions. Conclusion: Limited enzymolysis combined with glycosylation is a potential and reliable way to develop SPI-based emulsifying ingredients.

Keywords

• soybean protein isolate
• enzymolysis
• glycosylation
• emulsifying properties
• stability