Perubahan komponen volatil selama fermentasi kecap

Abstract

A study has been conducted to investigate changes of volatile components during soy sauce fermentation During the fermentation, many volatile components produced may contribute to soy sauce flavor. The volatile components identified by GC-MS were classified into hydrocarbon (15), alcohol (15), aldehyde (14), ester (14), ketone (9J, benzene derivative (11), fetfy acid (9!, furan (5), terpenoid (18), pyrazine (3), thiazole (1), pyridine (1) and sulfur containing compound (2). Concentration of compounds found in almost all fenrmntation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in rait soybean and their concentration did not cfiange during fermentation Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linobic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4- decadienai decreased or undetected during fermentation. The absence of some volatile compounds, e.g. (E}-nerolidol and (E,B)-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling, Some volatile compounds such as, methyl heptadecanoate 3ncf few aromatic alcohols arc.- likely derived from Aspergillus sojac, since these compounds were identified only in 0 day koji.