VOLATILE COMPOUNDS PRODUCED BY THE FUNGUS ASPERGILLUS-ORYZAE IN RICE KOJI AND THEIR CHANGES DURING CULTIVATION

The volatile compounds produced by growing the fungus Aspergillus oryzae on steamed rice, during koji making, were collected with a Tenax-TA column and analyzed by GC and GC-MS. Eight kinds of alcohols, three kinds of aldehydes, five kinds of ketones, and an ester were identified. The production of volatile compounds was affected by the oxygen concentration. Alcohols and aldehydes were especially increased by a deficiency of oxygen. The production of volatile compounds was maximum at the middle stage of growth and decreased thereafter. The results of semicontinuous analysis of mycelial growth and the production of volatile compounds showed that the tendency of the almost volatile compounds corresponded better with the mycelial growth rate than the mycelial weight. The tendency of 1-octen-3-ol was different from other volatile compounds; it increased with the cultivation time and didn't decrease. © 1989.