Seasonal Changes in the Standing Stock of Essential Polyunsaturated Fatty Acids in the Biomass of Phyto- and Zoobenthos on a Littoral Station of the Yenisei River

A comparative study of the composition of fatty acids in muscles, liver and internal fat in rainbow trout Parasalmo mykiss (Walbaum, 1792) grown on various diets in the period from April to July was effected. Differences in content of dietary fatty acids in diet 1 and diet 2 were found. A significantly lower level of long-chain polyunsaturated fatty acids (including physiologically significant eicosapentaenoic 20: 5(n-3) and docosapentaenoic 22: 6(n-3) acids) was detected in diet № 2, compared to diet № 1. As a result, deficiency of dietary eicosapentaenoic and docosapentaenoic acids leads to a slow rate of fishes growth. A significant influence of the trophic factor on the distribution of fatty acids in muscles and internal fat of fish is shown, because lipids in rainbow trout accumulate in these tissues. The degree of accumulation of different dietary fatty acids in muscles and internal fat of trout was depended on fatty acids that prevailed in the diet on which the rainbow trout was grown. A high degree of influence of the trophic factor on the level of polyunsaturated fatty acids of families n-9 and n-4 was found, the content of which in trout tissues was about 1%. Composition of fatty acids in trout liver, as the most metabolically active organ, is less conditioned by the influence of the factors studied. The degree of assimilation of docosahexaenoic 22: 6 (n-3) acid in rainbow trout probably depended on the level of eicosapentaenoic 20: 5 (n-3) acid in the diet. It has been stated that changing the level of fatty acids in muscles and internal fat of trout during seasonal changes is associated with an increase in the frequency of feeding of fishes in the summer.

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Determination of Seasonal Changes on Lipid Content and Fatty Acids of Nemipterus randalli (Russell, 1986) from Mersin Bay

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v8i8.1623-1629.3311 ◽

2020 ◽

Vol 8 (8) ◽

pp. 1623-1629

Author(s):

Mısra Bakan ◽

Nahit Soner Börekçi ◽

Deniz Ayas

Keyword(s):

Fatty Acids ◽

Oleic Acid ◽

Fatty Acid ◽

Polyunsaturated Fatty Acids ◽

Stearic Acid ◽

Palmitic Acid ◽

Lipid Content ◽

Seasonal Changes ◽

Monounsaturated Fatty Acids ◽

Spring Season

In this study, the seasonal changes on lipid content and fatty acid levels of Nemipterus randalli from the Mersin Bay have been determined. Total lipid levels were found as 3.17%, 2.12%, 0.63%, and 0.72% in spring, summer, autumn and winter seasons, respectively. The fatty acid composition of this species is composed of 30 fatty acids. Major fatty acids are palmitic acid (C16:0) and stearic acid (C18:0) from saturated fatty acids (SFAs) oleic acid (C18:1n9c) and 11-docosenoic acid (ceteloic; C22:1n11) from monounsaturated fatty acids (MUFAs) and eicosapentaenoic acid (EPA; C20: 5n3), and docosahexaenoic acid (DHA; C22: 6n3) from polyunsaturated fatty acids (PUFAs). The highest level of palmitic acid was detected in the winter season, and the palmitic acid level varied between 15.41% and 20.72% (77.79-433.30 mg/100g). The highest level of stearic acid was determined in the spring season, and its levels varied between 14.75% and 19.14%, and its levels were also determined as 77.95-483.91 mg/100g. Oleic acid from the monounsaturated fatty acids varied between 5.46% and 7.98%, and its levels were found to be 31.98-224.38 mg/100g. Ceteloic acid varied between 5.73% and 7.80%, and its levels were determined to be 33.01-161.11 mg/100g. The EPA levels from the polyunsaturated fatty acids ranged from 4.34 to 5.34%, and its levels were found to be 19.30-137.50 mg/100g. The highest levels of DHA were detected in autumn, its levels varied between 21.09% and 23.00%, and its levels have also been detected as 102.30-604.25 mg/100g. The highest levels of Σn3, Σn6 and Σn9 were found in the spring season. The levels of Σn3, Σn6 and Σn9 varied between 26.73-27.19% (122.89-751.59 mg/100g), 4.19-4.79% (18.63-134.68 mg/100g) and 5.95-9.79% (35.22-247.15 mg/100g), respectively. AI and TI values in N. randalli were found at 0.28-0.36% and 0.33-0.36%, respectively.

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