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

摘要

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 I kg on fatty acid profile and cholesterol content in raw and cooked broiler leg meat. Copper was added to feed mixtures as CuSO4.5H(2)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 x 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.