Steam explosion enhances phenolic profiles and antioxidant activity in mung beans

Steam explosion (SE), as a physicochemical pretreatment process, has the dual effect of high temperature and high pressure. In this study, SE was applied to pretreat mung beans to increase phenolic extraction and their antioxidant activity. It can make the material loose and porous, which is beneficial to the release of phenolic compounds from mung beans. Insoluble-bound phenolics (IBPs) were the dominating fraction, followed by glycosidic phenolics (GPs) and esterified phenolics (EPs), and free phenolics (FPs) were the lowest in mung beans. After SE, the maximum contents of FPs, EPs, GPs, IBPs, and total phenolics were detected at 0.75 MPa for 30 s, which were 1.47-, 1.87-, 1.73-, 1.48-, and 1.58-fold compared with the untreated samples, respectively. On the whole, the effect of SE on phenolics in mung beans first increased and then decreased. SE increased the contents of protocatechuic acid