Influence of dietary vitamin e and copper on fatty acid profile and cholesterol content of raw and cooked broiler meat

Abstract

We examined the influence of a diet containing 4% of rapeseed oil, 35 mg or 126 mg copper and supplement of 100 mg vitamin E per 1 kg on fatty acid profile and cholesterol content in raw and cooked broiler leg meat. Copper was added to feed mixtures as CuSO<sub>4</sub>.5H<sub>2</sub>O. The fatty acid profile and cholesterol content were also determined in raw, stewed and roasted meat of broilers receiving the same diet but with a supplement of 20 mg vitamin E. The results showed that 126 and 35 mg Cu/kg significantly increased oleic acid content. Monounsaturated fatty acids accounted for 51% and 52% of all fatty acids. The relatively low copper concentration of 35 mg/kg feed with a major portion of soybean, wheat and maize and vitamin E supplementation of 100 mg/kg reduced (P < 0.01) EPA by 17%, DPA by 16% and DHA by 11 and 15% (P < 0.05). All tested copper doses reduced cholesterol: 126 mg Cu by 22%, 35 mg by 6% and 126 mg in combination with 35 mg copper in relation to broiler age by 7% (P < 0.05); none of the cooking procedures influenced cholesterol. Meat cooking in experiment 1 did not influence the content of any fatty acid. Copper × cooking interactions were insignificant for all fatty acids and cholesterol. In experiment 2 more changes in the numerical values of fatty acids were caused by stewing compared to roasting. Among the valuable fatty acids n-3 long chain acids were influenced by both cooking procedures to the largest extent. Docosahexaenoic acid was reduced to about 60% of the original value (P < 0.05). On the other hand, a decrease in myristic acid by 14% in stewed meat and 12% in roasted meat (P < 0.05) was positive.