In this study, mung bean was subjected to instant high-temperature fluidization treatment at 160, 180, or 200 ℃. The effects on the starch digestibility of mung bean were investigated by analyzing alterations in microstructure, protein, and starch properties before and after the treatment. The results showed that the starch granules remained intact after the treatment. flocs appeared on the starch surface and their volume rose as the temperature increased. The protein network in mung bean gradually contracted, causing starch granules to aggregate into clusters and forming a compact protein barrier layer encapsulating the starch aggregates. High-temperature fluidization had no significant effect on the secondary structure of proteins (P < 0.05), while the disulfide bond content initially decreased and then increased with increasing temperature. The total starch content and crystal type (A-type) of mung bean remained unchanged after the treatment. However, the amylose content increased from 30.09% to 40.17%, the crystallinity decreased from 22.38% to 15.86%, and the short-range order of starch significantly reduced. Meanwhile, the gelatinization temperature, gelatinization enthalpy, and pasting parameters decreased significantly, indicating markedly improved cooking properties. The resistant starch content increased by 13.52%, and the estimated glycemic index decreased from 51.75 to 44.54. In conclusion, high-temperaturefluidization is a mild processing method that can generate a protein barrier layer around starch to slow down starch digestion and significantly increase amylose content, thereby achieving effective regulation of starch digestibility. This study provides technical support for the development of functional foods based on mung bean.

In this study, sequential hydrolysis with pepsin followed by trypsin was conducted on total protein and protein fractions from mung bean. The difference in α-amylase inhibitory activity among the resulting hydrolysates was compared and the underlying reason was analyzed in terms of degree of hydrolysis, amino acid composition and molecular mass. The results showed that the total protein hydrolysate had the highest α-amylase inhibitory activity (16.51%). Compared with its fractions, the total protein showed the highest content of hydrophobic amino acids (32.68%) and degree of hydrolysis (6.28%), and the molecular mass of its hydrolysate was the lowest (< 20 kDa). Therefore, the total protein was selected to prepare α-amylase inhibitory peptides. Finally, 17 peptides with potential α-amylase inhibitory activity were discovered by the isolation and identification of peptides from mung bean protein. This study suggests that mung bean protein is a better food source of α-amylase inhibitory peptides than its protein fractions, which can be used in blood glucose-lowering functional foods or drugs.