Effects of Three Drying Processes on Volatile Substances and Sensory Characteristics in Lentinus edodes

In order to study the effects of three-stage microwave vacuum freeze-drying(TS-MVFD),freeze-drying(FD)and hot air drying(HAD)on the volatile substances and sensory characteristics of Lentinus edodes,fresh whole shiitake mushrooms were used as raw materials,and analyzed by electronic nose,HS-SPME-GC-MS and scale sensory evaluation techniques. The results showed that the drying time of TS-MVFD,FD and HD were 5,14 and 7.5 h,respectively,when mushrooms wet basis moisture contents were dehydrated to 13%(w.b.)or less. The E-nose could distinguish the volatile components of three kinds of dried mushrooms. A total of 56,44,40 volatile compounds were detected under three different dying treatment. The dried mushroom products produced by TS-MVFD drying technology were mainly alkane and sulfur compounds such as 1-octene-3-ol,undecane,and lentin. The FD samples were mainly alcohols and hydrocarbons,such as 1-octene-3-ol,undecane,and acetaldehyde. HAD samples contained high levels of sulfur compounds,mainly dimethyl disulfide,dimethyl trisulfide,lentin. The color and shape of dried mushroom products of FD remained the best. After rehydration,the flavor properties of mushroom flavor,umami taste,and returning sweetness,as well as the taste properties such as elasticity,tenderness,smoothness and juiciness of TS-MVFD samples were significantly higher than those of HAD and FD samples. Conclusively,TS-MVFD was a kind of drying method for mushrooms with promotion value.