Identification of distinctive volatile compounds in fish sauce.

To make clear the distinctive odorants of fish sauce, addition tests were carried out with respect to deodorized fish sauce samples. Volatiles from the headspace gas of nontreated fish sauce and deodorized fish sauce were characterized by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Four compounds contributing to the distinctive odor of fish sauce were 2-methylpropanal, 2-methylbutanal, 2-ethylpyridine, and dimethyl trisulfide. Addition tests (quantitative descriptive analysis) with respect to the four odorants showed that contributors to the fishy aroma were 2-ethylpyridine and dimethyl trisulfide and that all four odorants contributed to the sweaty aroma. Furthermore, the fecal note of fish sauce was essential with 2-ethylpyridine and dimethyl trisulfide, and the rancid note was essential with all four odorants.