Shoyu (Soy Sauce) Flavor Components: Neutral Fraction

Abstract

Fromthe vacuumdistilled volatiles of shoyu, a neutral fraction was obtained. Shoyu was also directly extracted with dichloromethane and then the extract was separated into ten (AJ) fractions. The J fraction was a neutral one. The J fraction was further separated into twelve fractions by liquid column chromatography. All fractions obtained were analyzed by gas chromatography and combined gas chromatography-mass spectrometry. Consequently, 142 components were identified, 82 of which have not been reported previously as volatile constituents of shoyu. The identified compounds were 37 hydrocarbons, 22 alcohols, 22 carbonyls, 22 esters, 12 furans, 6 sulfurous compounds, 1 pyrone, 5 phenols, 1 furanone, 1 acid, 1 lactone and 12 other compounds.Fromthe results of quantitative analysis and organoleptic evaluation, phenylacetaldehyde is considered to be most important in the neutral fraction.