Functional and structural properties of soy 11S globulin: Influence of reverse micelle extraction

The effect of the reverse micelle extraction method (RMEM) on the physicochemical properties of soy 11S globulin was studied and compared with that of the traditional alkali solution-acid precipitation method (ASAPM). The results showed that the β-sheet structure content of soy 11S globulin obtained by RMEM was lower, while the β-turn structure content was higher compared with that obtained by ASAPM. Furthermore, the protein unfolding degree and surface hydrophobicity were lower than those observed using ASAPM. Therefore, RMEM better maintained the natural molecular structure of soy 11S globulin. The thermodynamic and rheological properties of soy 11S globulin obtained by these two methods were further compared, showing that the highest denaturation temperature and transition heat of soy 11S globulin extracted using ASAPM were different from those obtained using RMEM. Furthermore, soy 11S globulin extracted by RMEM showed stronger heat resistance and a higher denaturation temperature than that extracted by ASAPM. The final storage modulus and frequency sweep results showed that the gel formed by soy 11S globulin obtained using RMEM had high storage modulus and loss modulus. PRACTICAL APPLICATION: In this study, the effects of two different extraction methods on structural and functional properties of soy 11S globulin, such as thermodynamics and rheology, were investigated. We can know the 11S globulin extracted using the reverse micelle environment was more heat-resistant and heat-induced gel quality of 11S globulin was improved by the reverse micelle environment. These results will provide theoretical basis that would help determine the potential applications of soy 11S globulin in the food system.