家庭冰箱冷藏猪肉的微生物变化

Variation of Microorganisms in Refrigerated Pork During Household Consumption

了解居民家庭冰箱冷藏猪肉的微生物变化,为居民安全冷藏食品提供参考,以购自北京市海淀区大型超市和农贸市场的50份鲜猪肉为样品,采用微生物测试片法检测家庭冰箱冷藏18~24h猪肉的菌落总数、大肠菌群及金黄色葡萄球菌、沙门氏菌和单增李斯特氏菌变化。结果表明:猪肉经家庭冰箱冷藏后的菌落总数和大肠菌群数量均增加。冷藏前和冷藏后的平均菌落总数分别为(19.95±4.08)10~3cfu/g和(68.57±14.23)10~3cfu/g,大肠菌群数量分别为(1.34±0.14)10~2cfu/g和(6.87±1.15)10~2cfu/g,冷藏前和冷藏后菌落总数和大肠菌群数量的差异均达显著水平(P<0.05)。猪肉在家庭冰箱冷藏前后的金黄色葡萄球菌阳性样品数分别为2份和9份,单增李斯特氏菌阳性样品数分别为1份和3份,差异达显著水平(P<0.05);沙门氏菌阳性样品数分别为0和1份。家庭冰箱冷藏猪肉存在微生物污染隐患。

In order to understand the contamination status of the refrigerated pork from home via microbial indicators,and to provide basis view for understanding whether the use of refrigerator is safe at home.A total of 50 samples of raw pork meat were collected in supermarkets and farmers＇ markets in Haidian District,Beijing.All samples were equally separated into two portions.One was brought back and detected in laboratory directly,and the other one was kept in domestic refrigeration for 18～24hand detected later.Microbial testing method was used to detect the changes of aerobic plate count,coliform count,Staphylococcus aureus,Salmonella spp and Listeria of the pork before and after refrigerated storage.Results：Compared the pork stored in the refrigerators in the families with the pork from markets,the number of aerobic plate count and coliforms bacteria significantly increased,the mean number of aerobic plate count increased from（19.95±4.08）10^3cfu/g to（68.57±14.23）10^3cfu/g,and coliforms bacteria increased from（1.34±0.14）10^2cfu/g to（6.87±1.15）10^2cfu/g.Before and after refrigerated storage,the number of positive S.aureus samples significantly increased from two to nine,and that of positive Listeriasamples significantly increased from one to three too;The number of positive Salmonella spp samples before and after refrigerated storage was respectively zero and one.Microbial contamination is existent in domestic refrigerators.