Samelis J, Kakouri A, Georgiadou K G, Metaxopoulos J
Agricultural University of Athens, Department of Food Science and Technology, Greece.
J Appl Microbiol. 1998 Apr;84(4):649-60. doi: 10.1046/j.1365-2672.1998.00392.x.
In an attempt to determine the composition and origin of the spoilage flora of refrigerated vacuum-packed cooked ham, the changes in microbial numbers and types were followed along the processing line. Results revealed Lactobacillus sake and Leuconostoc mesenteroides ssp. mesenteroides as the major causative agents of spoilage of sliced ham stored at 4 degrees C and 12 degrees C, due to recontamination in the cutting room. On the contrary, the progressive deterioration of whole ham under the same storage conditions was associated with a non-identifiable group of leuconostoc-like bacteria. Except for lactic acid bacteria, no other organism grew in vacuum packs of either sliced or whole ham. Although atypical leuconostocs could not be detected among isolates recovered from freshly produced whole ham, they appeared to survive cooking and proliferate during storage. Neither these organisms however, nor Lact. sake and Leuc. mesenteroides were important in curing and tumbling as carnobacteria, mainly Carnobacterium divergens, and Brochothrix thermosphacta dominated at this stage. A progressive inversion of the ham microflora from mostly Gram-negative at the beginning of processing to highly Gram-positive prior to cooking was noted. Listeria monocytogenes cross-contaminated ham during tumbling. However, the pathogen was always absent from the vacuum-packed product provided that heating to a core temperature of 70 degrees C occurred and recontamination during slicing and packing was prevented. The percentage distribution of different species of lactic acid bacteria as well as the uncommon phenotypic characteristics of some strains were discussed.
为了确定冷藏真空包装熟火腿腐败菌群的组成和来源，对加工线上微生物数量和种类的变化进行了跟踪。结果显示，由于在切割室受到再污染，清酒乳杆菌和肠膜明串珠菌肠膜明串珠亚种是在4℃和12℃下储存的切片火腿腐败的主要致病菌。相反，在相同储存条件下，整只火腿的逐渐变质与一组无法鉴定的类明串珠菌有关。除乳酸菌外，切片火腿或整只火腿的真空包装中没有其他微生物生长。虽然从新鲜生产的整只火腿中分离出的菌株中未检测到非典型明串珠菌，但它们似乎在烹饪后存活并在储存期间增殖。然而，这些微生物以及清酒乳杆菌和肠膜明串珠菌在腌制和翻滚过程中并不重要，因为肉食杆菌，主要是分歧肉食杆菌和热杀索丝菌在这个阶段占主导地位。注意到火腿微生物群从加工开始时主要为革兰氏阴性菌逐渐转变为烹饪前高度革兰氏阳性菌。单核细胞增生李斯特菌在翻滚过程中交叉污染火腿。然而，只要加热至核心温度70℃并防止切片和包装过程中的再污染，真空包装产品中就始终不存在这种病原体。讨论了不同乳酸菌种类的百分比分布以及一些菌株不常见的表型特征。
