Seasonal variations in the fatty acid composition of phospholipids and triacylglycerols of brown trout

Abstract

Seasonal variations on phospholipid (PL) and triacylglycerol (TG) fatty acid (FA) compositions in muscles of Salmo trutta macrostigma were investigated by gas chromatography (GC) using the method described by Folch. The total lipid of the muscle was extracted using chloroform/methanol (2:1, v/v) and was separated into TG and PL using thin layer chromatography (TLC). A total of nineteen and sixteen different fatty acids were determined in TG and PL, respectively. The distributions of SSFAs (saturated fatty acids), SMUFAs (monounsaturated fatty acids) and SPUFAs (polyunsaturated fatty acids) proportions were found to be different among PL and TG fractions in all seasons. TG contained a lower proportion of SPUFA, but a higher proportion of SMUFA and SSFA than PL. The major components were palmitic acid (16:0), oleic acid (18:1 n-9), eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) in PL, 16:0, palmitoleic acid (16:1 n-7), 18:1 n-9, linoleic acid (LA, 18:2 n-6), linolenic acid (ALA, 18:3 n-3), 20:5 n-3 and 22:6 n-3 in TG extracted from muscle of S. trutta macrostigma in all seasons. The total lipid content varied seasonally from 1.44% to 1.90% in female muscle of wet weight for S. trutta macrostigma. N-3/n-6 ratios of PL and TG were found to be 5.19-12.0 and 1.09-2.62, respectively. Practical applications:The information in this study will be of practical value from a health perspective for populations who consume S. trutta macrostigma and for food producers.

Comparison of Fatty Acid Contents in Major Lipid Classes of Seven Salmonid Species from Siberian Arctic Lakes

“…Fish polar lipids are commonly considered as a physiologically crucial lipid class that are rich in LC-PUFA, mostly in DHA and, to a lesser extent, in EPA [19,37,39]. Indeed, percentages of DHA and EPA in PL of various wild marine and freshwater species ranged as 11.5-55.7% and 2.6-14.6%, with average values of 31.4% and 7.4%, respectively [40][41][42][43][44][45][46]. The average levels of EPA and DHA in the fish species from our study coincided with the above ranges, except the EPA value of whitefish, 16.6%, which was a bit higher than the known values.…”

“…Triacylglycerols are considered to be relatively poor in LC-PUFA and preferably accumulate monoenoic C16-22 FA [18,19,37]. According to the available data, levels of DHA and EPA in fish TAG varied in intervals of 2.3%-23.3% and 1.1%-14.1%, with average values of 8.8% and 5.3%, respectively [40][41][42][43][44][45][46]. The percentages of both EPA and DHA of TAG in the fish species from our study well coincided with the above ranges (Table 5).…”

Effect of seasonal variation on lipid and fatty acid profile in muscle tissue of male and female Silurus triostegus

“…Furthermore, the seasonal variations of the factors mentioned could be effective in changing the FA composition of fish (Kayhan et al 2015;Kaçar and Başhan 2015).…”

Effect of season on the fatty acid profile of total lipids, phospholipids and triacylglycerols in <em>Mastacembelus mastacembelus</em> (Atatürk Dam Lake, Turkey)

“…The lipid and FA compositions of fish can differ depending on seasonal changes, along with food, age, sex and spawning period (Christiansen et al, 1989). The latest studies have reported that lipid composition was affected by seasonal variations (Kayhan et al, 2015;Kaçar et al, 2016). In the same fish species, the total lipid contents of the gonad and liver changed from 1.32 to 4.90% and from 1.32 to 3.94%, respectively (Kaçar and Başhan, 2016).…”