Biosynthesis of 2-Methylbutyl, 2-Methyl-2-butenyl, and 2-Methylbutanoate Esters in Red Delicious and Granny Smith Apples Using Deuterium-Labeled Substrates
Daryl D. Rowan, Heather Lane, John M. Allen, Simon Fielder, Martin Hunt
Journal of Agricultural and Food Chemistry
Abstract
2-Methylbutanoate esters, especially ethyl 2-methylbutanoate, are key contributors to fruit aroma. The biosynthetic origins and interconversions of 2-methylbutyl and 2-methylbutanoate esters in Red Delicious and Granny Smith apples were determined by feeding deuterium-labeled substrates with GC−MS identification of the deuterated aroma volatiles produced. Deuterium-labeled isoleucine was fed to apple peel, and 2-methylbutanoic-d3 acid, 2-methylbutanol-d3, and ethyl 2-methylbutanoate-d3 were fed as vapor to whole apples. An array of labeled 2-methylbutyl and 2-methylbutanoate esters was produced from each substrate with significant differences in products and product distributions between the two apple cultivars. Novel 2-methyl-(2E)-butenyl esters were identified as biosynthetic products in the aroma of Red Delicious but not Granny Smith apples. Keywords: Biosynthesis; apple; aroma volatiles; 2-methylbutyl; 2-methylbutanoate; 2-methyl-2-butenyl; deuterium
Extracted Claims
3 claims extracted from this paper into the knowledge graph
2-methyl-(2E)-butenyl esters identified as biosynthetic products in the aroma of Red Delicious apples
“Novel 2-methyl-(2E)-butenyl esters were identified as biosynthetic products in the aroma of Red Delicious but not Granny Smith apples.”
2-methylbutanoate esters contribute to fruit aroma
“2-Methylbutanoate esters, especially ethyl 2-methylbutanoate, are key contributors to fruit aroma.”
deuterium-labeled isoleucine fed to apple peel
“Deuterium-labeled isoleucine was fed to apple peel, and 2-methylbutanoic-d3 acid, 2-methylbutanol-d3, and ethyl 2-methylbutanoate-d3 were fed as vapor to whole apples.”