Abstract:

Differences in some physico-chemical properties of kidney bean and mung bean starches, including shape, size, solubility, swelling power, transparency, pasting and retrogradation properties, were compared. The results showed that most of the granules of kidney bean starch were oval in shape, with a diameter ranging between 17.89 μm and 28.80 μm, and the granules of mung bean starch were round or oval in shape, with a diameter ranging between 10.50 μm and27.59 μm. Compared with kidney bean starch, both the swelling power and solubility of mung bean starch began to increase obviously at a lower temperature, and were slightly higher at the same concentrations. The transparency of kidney bean starch paste was higher than that of mung bean starch paste, but became lower and lower than that of mung bean starch paste after a certain period of storage. It was easier to paste mung bean starch than to paste kidney bean starch. Furthermore, kidney bean starch had higher retrogradation speed than mung bean starch.

Key words: mung bean, kidney bean, starch, physico-chemical properties