Effect of Refrigerated Storage on Fillet Lipid Quality of Rainbow Trout (Oncorhynchus mykiss W.) Fed a Diet Containing Different Levels of DL a-Tocopherol Acetate

Authors : Mustafa YILDIZ, Erdal Şener & Hüseyin GÜN

Pages : 143-150

View : 15 | Download : 4

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The effect of refrigerated storage at 1 ± 0.3 ºC on vitamin E level, fatty acid composition and lipid oxidation of fillets was studied in 3 groups of rainbow trout fed diets supplemented with increasing levels insert ignore into journalissuearticles values(100, 300 and 500 mg kg-1 diet, respectively); of a-tocopherol acetate as antioxidant. Fish insert ignore into journalissuearticles values(initial mean weight 131 ± 1.0 g); were fed experimental diets for 58 days and reached a mean final weight of 299 ± 6.1 g, with growth differences among the 3 experimental groups being insignificant insert ignore into journalissuearticles values(P > 0.05);. Fillet samples of fish were analyzed fresh insert ignore into journalissuearticles values(on day 0); or after storage at 1 ± 0.3 ºC for 9 days. Lipid oxidation was measured using the thiobarbituric acid reactive substances insert ignore into journalissuearticles values(TBARS); test. Dietary vitamin E levels had a significant effect on fillet a-tocopherol levels and TBARS values of fish by the end of 58 days of feeding. At the end of the feeding trial the fillet a-tocopherol levels of fish fed E100, E300 and E500 diets were 30.1 ± 0.2, 34.3 ± 0.1 and 40.1 ± 0.1 mg kg-1, respectively, and the fillet a-tocopherol levels were gradually decreased during the 9 days of storage at 1 ± 0.3 ºC insert ignore into journalissuearticles values(P < 0.05);. However, at the end of the feeding trial the fillet TBARS values of fish fed diets were 4.4 ± 0.1, 4.2 ± 0.0 and 2.2 ± 0.0 mg malondialdehyde insert ignore into journalissuearticles values(MDA); kg-1, respectively, and the fillet TBARS values gradually increased during the 9 days of storage at 1 ± 0.3 ºC insert ignore into journalissuearticles values(P < 0.05);. Dietary vitamin E levels did not influence the fatty acid composition of the fish fillets insert ignore into journalissuearticles values(P > 0.05);. However, during the refrigerated storage period, total saturated fatty acid insert ignore into journalissuearticles values(SFA); concentration slowly increased and total polyunsaturated fatty acid insert ignore into journalissuearticles values(PUFA); concentration slowly decreased insert ignore into journalissuearticles values(P < 0.05);. Finally, increasing the levels of a-tocopherol acetate in the diets from 130 to 580 mg kg-1 can slow down the level of lipid oxidation in fish fillets during refrigerated storage for 9 days at 1 ± 0.3 ºC.
Keywords : Rainbow trout, nutrition, a tocopherol acetate, fillet, refrigerated storage, lipid oxidation