Starch digestibility of various Japanese commercial noodles made from different starch sources

To examine the effect of starch variety and structure-related attributes on noodle starch digestibility, cooked Japanese commercial noodles, such as Harusame (mung bean starch), Malony (potato starch) and Udon (wheat flour), were kinetically analyzed during simulated in vitro digestion. The kinetic constant of the homogenized noodle slurry (10.8 × 10^-2-22.9 × 10^-2) was 10-20 times higher than that of the intact one (0.9 × 10^-2-1.5 × 10^-2), whereas the equilibrium starch hydrolysis (%) was equivalent. Therefore, the noodle microstructure, which is influenced by the present of binding agent and enhancer, should relate to the starch digestibility. Also, the starch digestibility at the early small intestine phase was associated with the cohesiveness and water retention ability of the cooked noodles. These results indicate that the internal microstructures of cooked noodles and the binding agent properties play an important role in the starch digestibility of noodles.