Volatile Compounds in Fresh and Processed Shiitake Mushrooms (Lentinus edodes Sing.)

Abstract

Volatile compounds of shiitake mushroom (Lentinus edodes Sing.) samples were extracted by solid phase microextraction (SPME) and then analyzed by GC and GC-MS. Fresh shiitake contained very low level volatile compounds, the major volatile compounds being: 1-octen-3-ol, 3-octanone, dimethyl disulfide and dimethyl trisulfide. During aging, all volatile cornpounds decreased rapidly. Fresh and crushed shiitake contained 6-4000 times more C₈ compounds than the uncrushed, the 3-octanone, 1,2,4-trithiolane, and 1-(methylthio)dimethyl disulfide contents increased and/or then decreased during aging. Drying of shiitake mushrooms caused loss of C₈ compounds and straight chain sulfur compounds such as dimethyl disulfide, however, it increased the cyclic sulfur compounds 1,2,4-trithiolane and 1,2,4,5-tetrathiane. Contents of 1,2,4-trithiolane and lenthionine in 40°C or 70°C water-soaked dried shiitake increased significantly during soaking. Changes of volatile compounds in fresh or 70°C water-soaked dried shiitake during heating in boiling water were also reported. Contents of lenthionine decreased significantly after heating in boiling water.