In Vitro Interactions on Glucose by Different Fiber Materials Prepared from Mung Bean Hulls, Rice Bran and Lemon Pomace

Abstract

Fiber was prepared from mung bean hulls, rice bran and lemon pomace by the chemical precipitation method and then characterized. The characteristics investigated included bulk density, water-holding capacity, oil-holding capacity, swelling properties, water solubility and glucose adsorption and diffusion in vitro experiments. The results showed that the smaller the fiber particles were, the higher the bulk density was and the lower the ability of the fiber was to absorb water and oil. Mung bean hull fiber had a significantly higher bulk density and water-holding capacity than cellulose. The swelling property of mung bean hull fiber was also significantly higher than that of cellulose. The water-holding capacity, oil-holding capacity and swelling property of rice bran fiber were all significantly higher than those values for cellulose. The water-holding capacity, oil-holding capacity, swelling property and water solubility of lemon pomace fibers were also significantly higher than those for the other experimental groups. The glucose effects in the in vitro experiments indicated that mung bean hull fiber had a higher level of adsorption when the glucose level was low. Fiber made from rice bran and lemon pomace had much better adsorption when exposed to high levels of glucose. In a mixed system including fiber, amylase and substrate, the level of glucose produced in the mixture containing lemon pomace fiber with a size <50 mesh was the lowest, and it was the best inhibitor of amylase activity. After 180 min of glucose adsorption, mung bean hull fiber with a size of 30-50 mesh was able to lower glucose diffusion. All of these mechanisms might contribute the rate reduction of glucose adsorption in the intestines, as a result, decrease the postprandial serum glucose concentration.