Abstract
Nineteen main volatile esters were detected from the headspace of strawberry fruit cv. Toyonoka, twelve of which were aliphatic esters which included abundant amounts of methyl butanoate and methyl hexanoate. Likewise, small amounts of thioesters, methylthiol acetate and methylthiol butanoate were also identified in strawberry fruit. A large amount of methylthiol acetate and ethylthiol acetate was produced when methanethiol and ethanethiol were added onto slices of strawberry, respectively. Thioester production was competitively inhibited by aliphatic alcohol, indicating that strawberry alcohol acetyltransferase (AAT) reacted with not only aliphatic alcohol but also thioalcohol which was converted to thioester. Strawberry-AAT had a weaker affinity with thioalcohols than corresponding aliphatic alcohols with the same carbon-chain structures. The thioalcohol specificity of strawberry-AAT had a similar pattern to the aliphatic alcohols, showing that the 1-hexanethiol and 1-pentanethiol were preferable substrates for strawberry-AAT than methanethiol and ethanethiol.
