Preparation, digestibility, and glucose response in mice of rice coated with resistant starch type 4 using locust bean gum and agar

This study investigated the technical feasibility of coating type 4 resistant starch (RS4) onto rice with the edible polymers locust bean gum (LBG) and agar. The coating solutions were prepared using LBG, agar, and a mixture of LBG and agar at three concentrations (0.01%, 0.1% and 1%). The raw milled rice was soaked in the prepared coating solutions, rolled in RS4 powder and dried. Microscopic observation revealed that the RS4 coating on the rice surface with 0.1% and 1% LBG-agar mixture had a resistance to washing and cooking and covered the whole surface of the rice with good adherence. The thickness of the RS4 coating on the rice surface with 0.1% and 1% LBG-agar mixture was approximately 74 and 233 μm, respectively. Compared with uncoated rice and rice mixed with RS4, the RS4-coated rice showed lower starch digestibility, a decreased glucose response and a slower rate of blood glucose decrease.