Relationship between surface functional properties and flexibility of soy protein isolate-glucose conjugates

Abstract

Flexibility had been determined to be an important indicator governing the surface properties of proteins and it was identified using the protease digestion method. In this study, the Maillard reaction between glucose and soy protein isolate was reacted under wet reaction conditions to obtain different flexible protein molecules. The effects of different reaction times (0, 2, 3, 4, 5, 6 h) on the flexibility, emulsifying and foaming properties of conjugates compared with soy protein isolate were studied and the correlation between them was analyzed by SPSS 20 Statistical Software. At the same time, the other structural indexes were also measured. These indexes changes responsible for the variation of flexibility were given detailed analysis. The results showed that emulsifying activity and emulsion stability were positively correlated with flexibility, the correlation coefficients were 0.976 (P < 0.01) and 0.968 (P < 0.01), respectively. Meanwhile, good correlations were obtained between foaming capability, foam stability and flexibility with correlation coefficients of 0.954 (P < 0.01), 0.754 (P < 0.05), respectively. In this study, the concept of flexibility was introduced into the effect of the Maillard reaction on the functional properties of soy protein isolate, which was of great significance.