Sagoo S K, Little C L, Allen G, Williamson K, Grant K A
Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, London NW9 5EQ, United Kingdom.
J Food Prot. 2007 Apr;70(4):943-51. doi: 10.4315/0362-028x-70.4.943.
A study of retail modified-atmosphere-packed and vacuum-packed cooked ready-to-eat meats was undertaken from September through mid-November 2003 to determine the microbiological quality at the end of shelf life and to establish any risk factors in the production, storage, and display of this product. Examination of 2,981 samples using Microbiological Guidelines criteria revealed that 66% were of satisfactory or acceptable microbiology quality, 33% were of unsatisfactory quality mainly due to high aerobic colony counts and Enterobacteriaceae concentrations, and 1% were of unacceptable quality due to the presence of Listeria monocytogenes at 100 CFU/g or higher (27 samples; range of 10(2) to 106 CFU/g) and Campylobacter jejuni (1 sample), indicating a risk to health. All samples at the end of the shelf life had satisfactory (<20 CFU/g) and/or acceptable (<102 CFU/g) levels of Staphylococcus aureus and Clostridium perfringens, four samples (<1%) had unsatisfactory levels of Escherichia coli (range of 102 to 106 CFU/g) and 5.5% of the samples contained L. monocytogenes at <20 CFU/g (4.8%) or between 20 and 100 CFU/g (0.7%). More samples of chicken (45%; 224 of 495 samples), beef (43%; 160 of 371 samples), and turkey (41%; 219 of 523 samples) were of unsatisfactory or unacceptable quality compared with ham (23%; 317 of 1,351 samples) or pork (32%; 67 of 206 samples). Twelve different L. monocytogenes typing characters (serotype-amplified fragment length polymorphism type-phage type) were evaluated for isolates recovered from samples of unacceptable quality, and the 1/2-IX-NT type was recovered from almost half (48%) of these samples. Salmonella was not detected in any samples examined. Risk factors identified for cooked meats that were microbiologically contaminated more frequently included vacuum packaging, packaging on retail premises, slicing, temperature not monitored in display units, and no hazard analysis system in place. Results from this study also suggest that the shelf life assigned to some modified-atmosphere-packed and vacuum-packed meats may not be appropriate.
2003年9月至11月中旬对零售的气调包装和真空包装即食熟肉进行了一项研究，以确定保质期结束时的微生物质量，并确定该产品生产、储存和展示过程中的任何风险因素。根据微生物准则标准对2981份样本进行检测，结果显示66%的样本微生物质量令人满意或可接受，33%的样本质量不令人满意，主要原因是需氧菌落数和肠杆菌科浓度较高，1%的样本质量不可接受，因为存在每克100 CFU或更高数量的单核细胞增生李斯特菌（27份样本；范围为10²至10⁶ CFU/g）和空肠弯曲菌（1份样本），表明存在健康风险。保质期结束时所有样本的金黄色葡萄球菌和产气荚膜梭菌水平均令人满意（<20 CFU/g）和/或可接受（<10² CFU/g），4份样本（<1%）的大肠杆菌水平不令人满意（范围为10²至10⁶ CFU/g），5.5%的样本含有每克<20 CFU（4.8%）或20至100 CFU/g（0.7%）的单核细胞增生李斯特菌。与火腿（23%；1351份样本中的317份）或猪肉（32%；206份样本中的67份）相比，鸡肉（45%；495份样本中的224份）、牛肉（43%；371份样本中的160份）和火鸡（41%；523份样本中的219份）的不合格或不可接受质量的样本更多。对从质量不合格样本中分离出的单核细胞增生李斯特菌的12种不同分型特征（血清型-扩增片段长度多态性类型-噬菌体类型）进行了评估，其中1/2-IX-NT型从几乎一半（48%）的此类样本中分离得到。在所检测的任何样本中均未检测到沙门氏菌。确定的熟肉微生物污染更频繁的风险因素包括真空包装、零售场所包装、切片、展示柜温度未监测以及未建立危害分析系统。该研究结果还表明，分配给一些气调包装和真空包装肉类的保质期可能不合适。
