Hellström Sanna, Kervinen Riitta, Lyly Marika, Ahvenainen-Rantala Raija, Korkeala Hannu
Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Finland.
J Food Prot. 2006 Jul;69(7):1565-70. doi: 10.4315/0362-028x-69.7.1565.
The efficacy of water, chlorinated water (100 ppm), peracetic acid solution (0.05%), and commercial citric acid-based produce wash (0.25%) to reduce the population of Listeria monocytogenes on precut lettuce was tested. Samples were inoculated with a mixture of equal amounts of five L. monocytogenes strains at a level of 4.7 log CFU/g, and analyzed on the day of washing and after 3 and 6 days of storage at 6 degrees C. Sanitizer reduced the number of L. monocytogenes at maximum 1.7 log CFU/g and number of L. monocytogenes reached the inoculation level during 6 days of storage. Thus, disinfectants do not eliminate L. monocytogenes on precut lettuce and cannot be solely relied on in producing precut lettuce safely. The inoculated L. monocytogenes strains were recovered at different rates after 6 days of storage; one of these strains was not recovered at all. Thus, strain-specific differences exist in the ability of L. monocytogenes to survive the washing treatments of the lettuce.
测试了水、加氯水（100 ppm）、过氧乙酸溶液（0.05%）和市售柠檬酸基农产品清洗剂（0.25%）对减少预切生菜中单核细胞增生李斯特菌数量的效果。样品接种了等量的五种单核细胞增生李斯特菌菌株的混合物，接种水平为4.7 log CFU/g，并在清洗当天以及在6℃下储存3天和6天后进行分析。消毒剂最多可将单核细胞增生李斯特菌数量减少1.7 log CFU/g，且在储存6天期间单核细胞增生李斯特菌数量达到接种水平。因此，消毒剂不能消除预切生菜上的单核细胞增生李斯特菌，在安全生产预切生菜时不能仅依靠消毒剂。接种的单核细胞增生李斯特菌菌株在储存6天后回收率不同；其中一种菌株完全未被回收。因此，单核细胞增生李斯特菌在生菜清洗处理后的存活能力存在菌株特异性差异。
