Glycinin-carbohydrate conjugates: Preparation, characterization, and application in processing of whole soybean curd

Glycinin-carbohydrate conjugate prepared with glucose, fructose, or dextran using a dry-heating method was applied to improve the processing quality and textural properties of whole soybean curd (WSC). The optimal parameters for preparing glycinin-carbohydrate conjugates were obtained using single factor experiment and response surface optimization. Compared to native glycinin, all glycinin-carbohydrate conjugates prepared under the optimized parameters exhibited improved solubility and emulsifying properties, especially the glycin-indextran conjugate. Yield, hardness, and gel strength of WSC were significantly elevated when glycin-incarbohydrate conjugates were applied as a part of raw material. For instance, when 15% glycinin-dextran conjugate was added, the yield, hardness, and gel strength of WSC were increased by 32.70%, 52.46%, and 32.72% compared to those of the WSC made only from soybean flour, respectively. Meanwhile, glycinin-carbohydrate conjugates modified the microstructure of WSC to be denser and more homogeneous, which was more significant in the glycinin-dextran conjugate-added WSC. In conclusion, glycinin-carbohydrate conjugates exhibited improved functionalities which were beneficial to facilitating the formation of homogenous microstructure and thus, enhancing the processing quality of WSC. Therefore, the addition of glycinin-carbohydrate conjugates could be considered a feasible alternative to elevate the processing quality and textural properties of whole soybean product.

Automated summary

The study successfully improved the processing quality and textural properties of whole soybean curd by preparing glycinin-carbohydrate conjugates, which exhibited enhanced functionality under optimized parameters. The addition of glycinin-carbohydrate conjugates significantly increased the yield, hardness, and gel strength of WSC, while also improving the uniformity and density of the microstructure.