Studies on the Aroma of Miso

Part IV. Role of miso components in volatile carbonyl production by heating

Abstract

The adsorbed fraction(Aa) and nomadsorbed fraction(Ab) from the Sendai-miso extract have been isolated by ultrafiltration and ion-exckange resin. Subsequently, 3-deoxyglucosone-free fraction(Ab')was separated from Ab. Changes occurred during the process of heating, mainly in voiatile carbonyl preuction, have been studied.
The ratio of volatile carbonyl amounts obtained from Aa and Ab by heating was about 3:2. Aldehyde and furfural were formed from the adsorbed fraction and the nonadsorbed fractions, respectively.
Ab differed from Ab' in the amount of volatile carbonyl production, and in the development of the characteristic heated flavor. In the sample of(Aa+Ab'), the change of 3-deoxyglucosone from accumulation to degradation was followed by the furfural formation.
These results showed the important contribution of 3-deoxyglucosone-containing fraction(Ac) as the intermediates related to the volatile carbonyl compound and the maltol-1ike flavor componnd in miso.