Microwave-vacuum drying characteristics and process optimization of Agaricus bisporus slices

Microwave-vacuum drying (MVD) was used to dry Agaricus bisporus slices, and its drying characteristics were studied. MVD was compared with hot air drying, vacuum drying and freeze-drying. The results showed that the effect of microwave power on drying rate was greater than that of vacuum degree during MVD process for Agaricus bisporus slices. The optimum drying parameters were microwave power intensity 17.4 W/g, vacuum 70 kPa and drying time 20 minutes, and moisture content of product was 6.9% under this condition. Comparing drying time, rehydration, color and vitamin C content, the qualities of slices dried by MVD was quite close to freeze-drying and obviously better than hot air drying and vacuum drying. Furthermore, MVD was much faster than freeze-drying. Therefore, MVD is a potential technology for drying Agaricus bisporus slices.