Analysis of Volatile Flavor Compounds of Sardine (Sardinops melanostica) by Solid Phase Microextraction

Abstract

Generally the main component of fishy flavor is considered to be trimethylamine. On the other hand, carbonyl compounds, produced from oxidation of polyunsaturated fatty acid by lipoxygenase or by autoxidation, might have some contribution to the fishy flavor. Since sardine skin contains high levels of polyunsaturated fatty acids and lipoxygenase, carbonyl compounds may be generated more easily than trimethylamine. In this study, volatile flavor compounds of sardine were analyzed by gas chromatograph-mass spectrometry and gas chromatograph-olfactometry combined with solid phase microextraction. Then, the flavor components that contribute to fishy flavor were identified. At normal pH (6.2), trimethylamine was not detected or sensed from the fresh sardines. When the pH was raised, the amount of trimethylamine became higher. Trimethylamine flavor was weak at pH 9 and strongly sensed at pH 11 or higher. On the other hand, 33 other compounds were positively or tentatively identified, including 8 hydrocarbons, 5 ketones, 1 furan, 1 sulfur compound, 12 aldehydes, and 6 alcohols in fresh sardines. Among them, 2,3-pentanedione, hexanal, and 1-penten-3-ol were the main components. Forty-seven flavors were detected by gas chromatograph-olfactometry. Among them, paint-like (1-penten-3-one), caramel-like (2,3-pentanedione), green-like (hexanal), shore-like ((Z)-4-heptenal), citrus note (octanal), mushroom-like (1-octen-3-one), potato-like (methional), insect-like ((E,Z)-2,6-nonadienal), and bloody note (not identified) were strongly sensed. From the aforementioned results, it can be concluded that these compounds rather than trimethylamine contributed to fresh sardine flavor.

Volatile compounds of some popular Mediterranean seafood species

“…These alcohols have been confirmed previously in sardines of various origins (Prost et al, 2004;Ganeko et al, 2008). With respect to the other pilchard volatiles, the profound presence of various carbonyls (2,3-pentanedione, pentanal, 2-butanone, cis-2-pentenal, hexanal, trans,trans-2,4-heptadienal and http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 11/05/2018 10:34:51 | trans-4-heptenal) and 2-ethylfuran in sardines have been reported previously and have been considered to contribute to a characteristic sardine-fishy odour (Triqui & Bouchriti, 2003;Prost et al, 2004;Ganeko et al, 2008).…”

Isolation and identification of two strains of pathogenic bacteria and their effects on the volatile metabolites of Gracilariopsis lemaneiformis (Rhodophyta)

“…Among the flavor compounds detected in sardine, seven compounds including 1-octen-3-one are strongly sensed. It is these compounds, rather than trimethylamine, that contribute to the fresh sardine flavor (Ganeko et al 2008). Powdery mildew due to the fungus Uncinula necator is a serious disease for vineyards.…”

Detection of flavor compounds in longissimus muscle from four hybrid pig breeds of Sus scrofa, Bamei pig, and Large White

“…No 13) but also in sardine (Sardinops melanostica) 14) and wild-cooked turbot (Scophthalamus maximus L.).…”