Efeito da desossa a quente e da temperatura de condicionamento na qualidade microbiologica da carne bovina embalada a vacuo. / Effects of hot boning and temperature conditioning on the microbiological quality of vacuum-packed beef.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The purpose of this study was to determine the effects of hot boning and temperature conditioning on the microbiological quality of vacuum-packed beef cuts using conventionally chilled meat as a comparison. Four experiments were conducted involving a total of 24 Nelore (Bos indicus), aged 30 to 36 months and approximately 450 kg in weight. They were slaughtered at the Meat Technology Centre of Institute of the Food Technology. Immediately after exsanguination, the carcasses were electrically stimulated with a potential difference of 21V (rms), 0.25 A, at a frequency of 60 Hz, 5s on, 1s off, for 90s. The L. dorsi (eye round) and Semitendinosus (striploin) were the muscles studied. The hot boned muscles were vacuum-packed and stored for 10h at 15°C (EQ15) or 25°C (EQ25). Temperature conditioning was performed in temperature-controlled rooms at 7°C and 3°C after temperature in the center of the muscles reached 10°C and 5°C, respectively. In the final stage, the cuts were left for aging in a storage room at 0 ± 2°C for 14 days (eye round) and 35 days (striploin). Microbiological counts were performed on the eye round and striploin cuts before the vacuum packing (0-time) and later, on the matured cuts at 2, 7, and 14 days. On the hot boned Striploin cuts, counts were also conducted 10 hours post mortem and on the matured cuts at 21, 28, and 35 days. The microbiological counts performed counted the total psychrotrophic aerobic; lactic acid bacteria; coliforms; Escherichia coli; sulfite-reducing clostridia, enterobacteric, and Pseudomonas sp. The total psychrotrophic population and lactic acid bacteria counts found in hot-boned samples were not significantly different (p>0.05) when compared with those of conventionally-boned cuts during the first 14 days. However, hot processing had a significant effect on the growth of these bacteria from the 21st day onwards. The coliforms were found only after 21 days of storage on the L. dorsi hot boned samples. The growth of coliforms was not detected during the whole aging period for the conventionally boned cuts. E. coli and sulfite-reducing clostridia were not found on the cuts eye round matured for 14 days or on the cuts striploin matured for 35 days. Pseudomonas sp., and enterobacteric showed a slight growth in eye round cuts after 14 days of aging and were not significantly different (p>0.05) among treatments . However, the best results were obtained for the hot boned cuts temperature conditioned for 10 hours at 15°C (EQ15). The microbiological quality of the processes evaluated was considered adequate. Up to 14 days at 0°C, hot boned beef had the same microbiological counts than conventionally boned beef. After the 21th day, bacteria counts tended to be larger in hot boned beef. However, those counts were still within recommended levels. There results indicate that meat obtained by hot boning conducted under strict hygiene condition does hot present microbiological characteristics significances different from conventionally boned meat.

ASSUNTO(S)

microbiology armazenamento embalagens temperatura storage packings temperature microbiologia

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