Hot Air-Microwave Combination Drying of chili

Abstract

This research was investigated the way to apply microwave power for hot air drying system.  The household microwave oven was modified to be a hot air-microwave combination dryer.  The dryer was tested to evaluate the drying performance by using chili.  chili samples were dried by hot air namely,  Hot air-microwave continuous drying, hot air-microwave preheating drying, hot air-microwave finish drying, and hot air-microwave pulse drying in teh experimental dryer.  Drying rate and energy consumption in term of specific moisture evaporation rate (SMER) were compared.  All of hot air-microwave combination methods resulted in increased SMER and shortening of the drying time when compred with hot air drying at the same drying air temperature.  The hot air-microwave pulse drying was the suitable method to apply microwave energy in conventional hot air drying of chili because it had the shortest drying time and highes tof SMER and product was not damaged by microwave heating.