SEMI-DRY METHOD FOR IMPROVING EMULSIFICATION OF SOYBEAN PROTEIN ISOLATE

To increase the emulsifying activity and emulsion stability of soybean protein isolate (SPI), the semi-dry method was used to modify SPI via cross-linking with malt dextrin (MD). The central composite design based on the response surface methodology was applied to study the effects of MD content added, water content added, reaction temperature and time on the emulsifying properties of SPI, and the regression models were established between the emulsifying properties and different factors. The results showed that the emulsifying activity of the modified SPI was 71.9m(2)/g, and its emulsion stability was 91.2% under the optimum conditions of 39% MD added, 18% water content and modified at 65C for 8.4h. Practical ApplicationsEmulsification of soybean protein isolate (SPI) can improve the food's structure and flavor. However, its emulsibility is low, which restricts its application in the food industry. In this study, the semi-dry method is first used to improve the emulsibility of SPI, which has the advantages as those of the wet and dry methods, i.e., it has a high productivity and reduces environmental pollution and production costs.