Effect of microwave and hot air drying on the quality of quick-cooking mung bean

Abstract

Recently, consumers prefer ready-to-eat foods due to their advantageous minimal input of time and effort. Soaking-cooking-drying is a typical procedure for preparing quick-cooking beans, where drying is the last but not least step. Therefore, this study aimed to compare the effect of microwave and hot air drying on the quality of quick-cooking mung bean. Mung bean was soaked, pre-cooked and then dried by microwave (60, 300, and 600 W) and hot air (50, 70, and 90 ºC). All dried beans exhibited a larger volume, a cracked surface, a browning color, a shortened cooking time, and an increased in vitro digestibility. However, microwave treatment decreased the drying time from ~120 to 25−30 min, and reduced the energy consumption by 0.04−0.15 kW·h. The quick dehydration process during microwave drying restricted the reassemble of gelatinized starch and the formation of weak V-type crystalline, thus further improving the digestibility of mung bean. Overall, this study suggested that microwave could be an alternative drying technique for preparing quick-cooking beans with high digestibility.

Keywords

• rehydration
• ready-to-eat food
• starch
• digestibility