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

摘要

Thigh muscles from aged (3-4 yrs) goat were minced, packed in polyethylene bags (250 g each), gamma-irradiated with a dosage of 4 kGy and the packets held at 3 +or- 1 degrees C for 8 days. Nonirradiated mince samples packed and stored similarly were treated as control. Both irradiated and nonirradiated mince were sampled on 0, 5 and 8 days of storage and analysed 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%), TBA 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. Reductions (P <= 0.05) of 2 log cfu/g in total aerobic bacteria and psychrotrophs, and 1 log cfu/g in total staphylococci, yeast and moulds were also observed in irradiated samples while enterococci, Escherichia coli and Staphylococcus aureus could not be detected in irradiated and stored mince. Sensory quality scores on a 9-point hedonic scale decreased from 7.5-8.3 to 7.1-7.9 during storage at 3 +or- 1 degrees C for 8 days, and were marginally influenced by irradiation. These results indicate that a 4-kGy dose of gamma-irradiation maintains fresh meat quality under chilled conditions.