Effect of Drying Methods on the Quality Characteristics of Boletus albus Peck and Termitomyces albuminosus

The effects of three drying methods, including microwave hot air combined drying (MHD), hot air drying (HAD) and vacuum freeze-drying (VFD) on the color quality, rehydration rate, texture properties and microstructure of Boletus albus Peck and Termitomyces albuminosus were investigated in this study. The results showed that, in terms of color quality, vacuum freeze-drying and microwave hot air combined drying owned better color quality than that of hot air drying. In the aspect of rehydration, vacuum freeze-drying method was much better than that of the other two methods, and the rehydration of Termitomyces albuminosus was superior to that of Boletus albus Peck. In terms of texture properties, the hardness, springiness and cohesiveness of the two kinds of fungi showed the same change under different drying methods:hot air drying>microwave hot air combined drying>vacuum freeze-drying. In terms of microstructure, the cross section of the two kinds of fungi with microwave hot air drying and vacuum freeze-drying presented a porous structure, while the porous net structure with hot air drying was not obvious. In general, vacuum freeze-drying was the first choice for the drying methods of Boletus albus Peck and Termitomyces albuminosus, followed by microwave hot air combined drying, hot air drying was not suitable.