INFLUENCE OF THE OXIDATIVE QUALITY OF DIETARY OIL ON BROILER MEAT STORAGE STABILITY

Broilers were fed a high fat diet containing 11% oil (9% rapeseed oil, 2% soya bean oil) and the oil was given either as fresh (peroxide val ue of 1 meqv. O(2)kg(-1) oil) or as highly oxidised (peroxide value of 156 meqv. O(2)kg(-1) oil). Diets were supplemented with 46 mg all-rac -alpha-tocopheryl acetate kg(-1) diet, resulting in a tocopherol conte nt of 80.8 mg alpha-tocopherol and 58.6 mg gamma-tocopherol per kg die t in the fresh oil diet and of 44.0 mg alpha-tocopherol and 18.3 mg al pha-tocopherol per kg diet in the oxidised oil diet, respectively, ref lecting the degradation of the natural occurring tocopherols in the ox idised diet. Only minor differences were seen with respect to fatty ac id composition in muscles from birds fed the two diets. The oxidation of the dietary oil lowered lipid stability significantly (p < 0.01) in both raw and precooked meats during chill storage, whereas only minor effects on the stability of frozen meat were seen. Tocopherol levels were significantly lower (p < 0.01) in muscles from birds fed the oxid ised oil diet, explaining the decreased lipid stability of meat from t hese birds. Thigh meat was more susceptible to lipid oxidation during storage than breast meat, regardless of dietary treatment, although th igh meat had markedly higher tocopherol levels than breast meat. The m olar ratio of PUFA > 18:2 (polyunsaturated fatty acids with three or m ove double bonds) to alpha-tocopherol was significantly (p < 0.01) hig her in thigh meat compared with br east meat, explaining the lower sta bility of the former during storage. (C) 1997 Elsevier Science Ltd. Al l rights reserved.