Influence of feed enriched with natural antioxidants on the oxidative stability of broiler meat

The effect of feed supplementation with natural α-tocopherol, rosemary, green tea, grape seed and tomato extracts on the oxidative stability of broiler meat was investigated by measuring lipid oxidation, protein oxidation and α-tocopherol content of breast muscle. Supplementation with α-tocopheryl acetate at a dietary concentration of 200 ppm was used as a control. The broilers were fed a diet containing 4% linseed oil for 6 weeks. The antioxidant extracts were supplemented in single and in combinations at total concentrations of 100 and 200 ppm. For lipid oxidation, the 200 ppm αtocopheryl acetate treatment yielded the lowest TBARS values. Dose effects were observed for αtocopherol, grape seed and tomato, while no dose effect was observed for rosemary. In contrast, green tea showed a pro-oxidative effect at 200 ppm. Combinations of α-tocopherol, rosemary and green tea did not reveal synergistic effects between the different extracts and strengthened the hypothesis of the pro-oxidative effect of green tea at higher doses. No differences between the different antioxidant treatments were detected for protein oxidation. The muscle α-tocopherol content linearly responded to the feed α-tocopherol content. No differences in α-tocopherol deposition was observed between the natural or the synthetic form.