Physicochemical properties and digestibility of starches isolated from ungerminated and germinated mung bean flour under heat-moisture treatment at different conditions

• Native and germinated mung bean flours were directly heat-moisture treated • Property and digestibility of starches isolated from treated flours were investigated • HMT significantly increased the thermal stability and solubility of treated starches • Heating temperature and moisture level greatly affected SDS and RS formation • Germinated flour (30% moisture) under HMT at 100°C for 6 h gave highest SDS and RS In this study, native or germinated mung bean flours were directly heat-moisture treated to modify their physicochemical properties and digestibility. Physicochemical properties and digestibility of starches derived from mung bean flours under heat-moisture treatment (HMT) or a combination of germination and HMT (G-HMT) were investigated. HMT was conducted with moisture content of 20%, 25%, or 30% at 100°C or 120°C. The results showed that neither HMT nor G-HMT affected the crystalline structure or morphological features of mung bean starches. Nevertheless, both treatments significantly increased the thermal stability and solubility of treated starches, while their swelling power and viscosities were noticeably lower as compared to the native mung bean starch. HMT of both native and germinated mung bean flours with higher moisture contents resulted in increased slowly digested starch (SDS) and resistant starch (RS) levels. As a result, the highest both SDS and RS contents were achieved when germinated mung bean flour with 30% moisture content was subjected to HMT at 100 °C for 6h. These findings suggest that G-HMT is a highly applicable approach for improving the amounts of SDS and RS of mung beans flour, thereby offering potential value for the development of functional foods.