Effects of Storage Time on the Quality of Local Chicken Meat
An experiment was carried out to investigate the proximate composition and effects of aging time on local chicken meat quality. For proximate analysis, 24 male and 24 female breast, thigh and drumstick samples from one half of the carcass were skinned, de-boned and frozen at -20oC. The samples were minced through a 5mm plate meat-grinding machine and vacuum packed prior to analyses. Proximate composition analysis of minced meat samples were performed on wet basis. The other half carcasses samples were chilled for 4, 6, 12 and 24 hours post mortem (PM) at 4oC. pH values were measured for each sample followed by storage at -20oC to arrest further changes in meat. Cooking loss and meat tenderness were determined for these samples. The proximate analysis showed that females had higher (P<0.05) overall dry matter and ether contents than males, while CP% and ash content were similar in the two sexes. Breast meat had higher (P<0.05) CP and ash content than meat cuts from the leg. Generally, breast meat had lower (P<0.05) pH (5.89) compared to meat from the thigh (6.14) and drumstick (6.15). pH of breast meat at 24 hours PM (5.82) was lower than that recorded at 4, 6 and 12 hours PM. Tenderness of meat as measured by shear force values significantly improved with storage time and decline in shear force values was more accentuated in the first six hours of aging. After this period, the values were less than 13.3N for drumstick and 18.9 N for both breast and thigh. The effect of storage time on cooking loss was more pronounced in leg meat than breast meat and cooking loss was much less when meat parts stored for 24 h. For production of acceptable tender meat from local chicken, the ideal cold storage time can be set at between 4 to 6 hours.
Key Words: Local chicken, Aging, Cooking loss, Meat pH, Tenderness, Proximate composition
FACULTY OF AGRICULTURE SOKOINE UNIVERSITY OF AGRICULTURE, MOROGORO, TANZANIA