Strategy for the identification of key odorants: application to shrimp aroma.

S Rochat, J Egger, A Chaintreau

Index: J. Chromatogr. A. 1216(36) , 6424-32, (2009)

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Abstract

The GC-SNIF technique was used to obtain the olfactograms of shrimps, and their impact odorants were identified by MS hyphenated to the GC/olfactometric system and by comprehensive two-dimensional GC hyphenated to a time-of-flight MS. Confirming these identifications by their linear retention indices required application of a new strategy to compare retention indices between both instruments and with the in-house database. The aldehydes were confirmed by using their pentafluorophenylhydrazone derivatives, and 2-ethyl-3,5-dimethyl pyrazine had to be resolved from co-eluting compounds and then identified by multidimensional GC hyphenated to an MS and a sniff port. In both shrimp products, the most important odorants were trimethylamine, 2-acetyl-1-pyrroline, and 2-ethyl-3,5-dimethyl pyrazine, together with common carbonyl compounds.