Chemical composition, fatty acid profile and colour of broiler meat as affected by organic and conventional rearing systems
The major quality characteristics of breast and thigh meat, including chemical composition, fatty acid composition, cholesterol content and colour of slow-growing broilers (Hubbard Red-JA), reared under either organic or conventional rearing systems, and fast-growing broilers (Ross-308) grown under the conventional procedure, were investigated in this comparative study. Slaughter age was 81 days and 42 days for slow- and fast-growing birds, respectively. A lower protein, but higher fat content was measured in the thigh meat of slow-growing broilers reared both in the organic and conventional systems, compared with conventionally reared fast growers. In both systems the breast meat of fast-growing birds had a higher moisture content than those of the slow-growing birds. The organic system promoted ash retention in breast meat compared with conventional rearing procedures. The fatty acid profile of thigh and breast meat showed different responses to broiler rearing systems. Both thigh and breast meat of conventionally reared slow-growing birds contained higher cholestorel levels. Breast and thigh meat yielded from conventionally reared fast-growing birds had a markedly higher red appearance, but a lower yellow colour, than those of slow growers. The organic system increased the yellowness of the meat. In conclusion, the organic rearing procedure provided no added benefit to chicken meat quality than current conventional applications, except in yellowness. Meat produced from birds in the organic system did not meet consumer expectations of presenting a lower n-3 but a higher n-6/n-3 ratio in thigh meat.
Keywords: Fast-growing broilers, slow-growing broilers, organic production, meat quality