Study on hot-air, vacuum-microwave drying of processing jujube and red bean puree

Jujube and red bean dehydrated by vacuum-microwave drying was compared with the hot air drying of the drying affects. Results showed that the moisture content gradually decreased during vacuum-microwave drying, while rapidly dropped during earlier period of hot-air drying. And vacuum-microwave drying took less time than hot-air drying. Water absorption, solubility characteristics, L value and VCcontent of hot air drying product were 3.3, 42%, 18.8 and 0.98mg/g, respectively. The above value of vacuum-microwave drying were3.5, 51%, 29.1, 9.02mg/g. The product qualities of vacuum-microwave drying are better than that of hot-air drying. The product of vacuum-microwave drying was esier to absorb moisture than of hot-air drying.