HOT AIR DRYING INDUCES BROWNING AND ENHANCES PHENOLIC CONTENT AND ANTIOXIDANT CAPACITY IN MUNG BEAN (VIGNA RADIATA L.) SPROUTS

摘要

Hot air drying has been widely used for the processing and preservation of freshrnfruits and vegetables. In this study, we investigated the browning of hot air driedrnmung bean (Vigna radiata L.) sprouts, as well as the antioxidant capacity andrnphenolic contents in their soluble and insoluble fractions. Hot air drying at 70rnand 80C for 24 h increased the browning of mung bean sprouts, and hot air driedrnsamples generally had higher total phenolic content and antioxidant capacityrncompared to the freeze-dried sample. Rutin, caffeic acid and p-coumaric acidrnwere identified in mung bean sprouts by LC–MS, and hot air drying at higherrntemperature (70 and 80C) reduced rutin and p-coumaric acid contents, whilernincreasing the content of caffeic acid. Browning pigments and polyphenols mayrnbe the main contributors of antioxidant capacity in hot air dried mung beanrnsprouts.