Changes in quality of minced meat from goat due to gamma irradiation

Thigh muscles from aged (3-4 years) goat were minced, packed in polyethylene bags (250 g each), gamma irradiated with a dosage of 4 kGy and the packets held at 3 +/- 1C for 8 days. Nonirradiated muscle mince packed and stored similarly were treated as control. Both irradiated and nonirradiated muscle mince were sampled on 0, 5 and 8 days of storage and analyzed for physicochemical, microbiological and sensory quality attributes. Irradiation resulted in lower (P <= 0.05) muscle pH (3.5-5.1%), water holding capacity (4.5-6.7%), thiobarbituric acid values (19.4-34.9%) and higher (P <= 0.05) free fatty acid (26.9-61.0%) and Hunter a* (3.3-17.3%) values compared with nonirradiated control muscle samples. A reduction (P <= 0.05) of 2 log cfu/g in total aerobic bacteria and psychrotrophs, and 1 log cfu/g in total staphylococci, yeast and molds were also observed in irradiated samples while enterococci, Escherichia coli and Staphylococcus aureus could not be detected ill irradiated and stored muscles. Sensory quality scores on a 9-point hedonic scale decreased from 7.5-8.3 to 7.1-7.9 during storage at 3 +/- 1C for 8 days and were marginally influenced by irradiation. The results establish that a 4-kGy dosage is appropriate for irradiation to maintain fresh meat quality under chilled condition.