The production of aroma by Aspergillus oryzae during the preparation of soy sauce koji

The rôle of koji in the preparation of soy sauce has been a subject of controversy. A study of the volatiles produced during koji preparation and a comparison with uninoculated bean-flour mixture shows that the growth and sporulation of Aspergillus oryzae is related to the production of volatiles. The volatiles present at the mycelial stage are different from the volatiles of sporulated koji. The ether extracts of the acidic homogenates were different from those of the neutral and alkaline homogenates.