THE INFLUENCE OF SEASON ON LIPID CONTENT AND FATTY ACIDS PROFILE OF EUTHYNNUS ALLETTERATUS FILLETS AND BY‐PRODUCTS

Abstract

The seasonal lipid variation and fatty acids compositions were assessed in white and red muscles, head, viscera, liver and gonads of little tuna Euthynnus alletteratus. Lipid contents showed a significant variation (P < 0.05) throughout the year, the maximum level was found in the liver during winter season (27.28 g/100 g). The lowest fat contents were found in gonads during the winter and spring seasons, with levels of 1.56 and 1.49 g/100 g, respectively. White and red muscle fat levels increased significantly from winter to summer; viscera lipids, however, showed a significant decrease during the same period. Generally, the increase of the polyunsaturated fatty acids percentage in most organs was usually accompanied with a decrease of saturated fatty acids. It was shown that lipid content was higher in the head and liver compared to other compartments, and the fatty acid composition in the different organs of little tuna was significantly influenced by spawning and season. All lipids extracted contained significant amounts of docosahexaenoic acid and eicosapentaeneoic acid, which have various physiological functions. PRACTICAL APPLICATIONS Most of the available literature showed little information about biochemical composition of fillets and by‐products of some fish species and are, therefore, not complete for industrial purposes as application in food or feed nutriment. The practical application of this study was performed by the determination of fatty acids levels of little tuna fillets (white and red muscles) and by‐products (head, viscera, liver and gonads) to further explain the evolution of lipid and fatty acids throughout the year. Finally, this manuscript may provide some valuable information for other scientists working in the field of food technology.

Quality Enhancement of Canned Little Tunny Fish (Euthynnus alletteratus) by Whitening Solutions, Pre-Cooking Time and Filling Medium

“…The most abundant fatty acids found in raw, precooked and whitened tunny fillets were Docosahexaenoic acid (C22: 6n-3), Palmitic acid (C16: 0), Oleic acid (C18: 1n-9), Stearic acid (C18: 0), and Eicosapentaenoic acid (C20: 5n-3). These findings are in agreement with those obtained by Selmi and Sadok [29], Connell [35]. Raw tunny also showed considerable amounts of Vaccenic acid (C18: 1n-7), Palmitoleic acid (C16: 1n-7), Myristic acid (C14: 0), and Linoleic acid (C18: 2n-6).…”

“…There was no significant difference (P>0.05) in the fat content among the pre-cooked tunny at different retention times. Generally, the light meat of little tunny has a low fat content this is an advantage, especially in product development, because the problem of rancidity can be reduced [29]. A significant increase (P<0.05) was noticed in protein and ash contents for various pre-cooked samples.…”

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“…However, proximate composition of fish may vary with species, size, sex, season and geographic harvest area (Selmi & Sadok, 2010). The yield of extracted oil may vary between traditional solvent extraction methods and SE.…”

Storage stability and quality of polyunsaturated fatty acid rich oil fraction from Longtail tuna (Thunnus tonggol) head using supercritical extraction

“…Longtail tuna head was rich in omega-3 fish oil, especially high amount of docosahexaenoic acid (DHA) (19.7%) (Sahena et al, 2013). Head of little tuna Euthynnus alletteratus represents an important source of polyunsaturated fatty acids (PUFA) (41.43-47.71%), especially omega-3 DHA (29.34-34.02%) (Selmi & Sadok, 2010). There are great differences in lipid storage between different fish species and various parts of the fish organ due to their size and age, location and season of catch, gender and food habit, reproductive cycle, salinity, and temperature (Boran, Karaçam, & Boran, 2006;Huss, 1988;Sahena et al, 2010).…”