Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

Abstract

We evaluated the effect of broiler age and aging process on the meat characteristics of breast fillets from female free-range broilers slaughtered at 12 weeks of age (Wk12) and 70 weeks of age (Wk70). We used breast meat from female ISA Label (n = 60) broilers. Ten samples of each broiler age were aged in an incubator (2°C ± 0.5°C) for 3 and 7 days. Ten samples for each broiler age were analysed 4 h post-slaughter (Control group). Compared with breast meat from Wk12, breast meat from Wk70 showed higher shear force (30.52 N vs 27.19∼ P = 0.0322) and total collagen (4.33 g/kg vs 3.77 g/kg∼ P = 0.0149), which were reduced during aging to 15.49 N and 3.92 mg/100 g, respectively. The aging process did not affect the lipid oxidation of breast meat from Wk70. After aging for 3 days, breast meat from Wk70 had similar protein and fat contents to those of meat from Wk12 (21.29% and 1.04%, on average, respectively). Breast meat from Wk70 also showed lower concentrations of docosahexaenoic (0.32% vs 0.65%∼ P < 0.0001) and eicosapentaenoic (0.01% vs 0.12%∼ P < 0.0001) fatty acids than meat from Wk12. The use of free-range hen meat is beneficial to the industry because of the lower storage and cooking losses, which may influence the final yield, besides its lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to promote the tenderisation of meat from free-range broiler hens.