Glycemic Response to White Kidney Beans as Part of a Rice Meal: A Thermal Processing Method

In this study, the heat treatment of white kidney beans was optimized by a single-factor experiment and an orthogonal experiment. Taking in vitro digestibility as an index, the optimum technological parameters for heating white kidney beans were determined as follows: water addition of 225%, medium pressure heating for 30 min, and a temperature of 110 °C. The results of scanning electron microscopy showed that the layered structure in white kidney beans disappeared, and the original particle morphology was lost. The protein network was broken, forming an irregular agglomerate or flocculent structure, and the porous structure formed by heat-induced crosslinking effectively delayed the contact of amylase. Heat-treated white kidney beans were added to rice, and their nutritional components were determined, and the glycemic index was estimated in vitro to determine the best addition amount. The results of the in vitro digestion rate showed that the rice treated with 40% white kidney beans significantly reduced the glycemic index (eGI = 41.48), and the texture analysis showed that the viscoelasticity of rice could be improved by compounding 40% white kidney beans. It also effectively improves the taste of 100% white rice. This study can provide interdisciplinary solutions for the development of staple food for diabetes and provide a scientific basis for the development of staple food with a low glycemic index and the improvement of traditional diets.