Abstract:
Hazard analyses were conducted at several cooked food vending operations in a large city in Zambia, near a downtown bus park and at a large market. Samples of raw, processed, and cooked foods sold on streets or by small food shops were collected and tested for common foodborne pathogens and indicator organisms. Results showed that some raw foods (ground meat, chicken, chicken intestine) or processed foods (dried minnows; kapenta) were contaminated by salmonellae or contained high populations of Staphylococcus aureus (pasteurized milk) or Bacillus cereus (caterpillars). Cooking usually gave time-temperature exposures that would have been lethal for vegetative forms of foodborne pathogens. Holding of foods other than nshima often provided time-temperature exposures conducive to microbial growth, particularly in foods held overnight. Large populations of aerobic mesophilic organisms, thermotolerant coliform bacteria, and sometimes Escherichia coli were recovered from these foods. Ten million Clostridium peifringens per gram were isolated from a sample of leftover beef stew. Large populations (> 105) of S. aureus were recovered from a sample of leftover chicken, and large populations of B. cereus (> 107) were isolated from leftover rice. Time-temperature exposures during reheating had variable effects in terms of killing the microorganisms that germinated from surviving spores or that reached the foods after cooking, but heat-stable toxins would not have been inactivated.
摘要:
在赞比亚一个大城市的几个熟食自动售货机进行了危害分析,在市中心的公共汽车公园和一个大市场附近。原始样品,已处理,收集街头或小型食品店出售的熟食,并测试常见食源性病原体和指示生物。结果表明,一些生食(碎肉,鸡肉,鸡肠)或加工食品(干of鱼;kapenta)被沙门氏菌污染或含有大量金黄色葡萄球菌(巴氏杀菌乳)或蜡状芽孢杆菌(毛虫)。烹饪通常会产生时间-温度暴露,这对营养形式的食源性病原体是致命的。持有nshima以外的食物通常会提供有利于微生物生长的时间-温度暴露,特别是在食物中过夜。大量的需氧中温生物,耐热大肠杆菌,有时从这些食物中回收大肠杆菌。每克从剩余的炖牛肉样品中分离出一千万个贝弗林梭菌。从剩余的鸡肉样品中回收大量金黄色葡萄球菌(>105),从剩余的水稻中分离出大量的蜡状芽孢杆菌(>107)。再加热过程中的时间-温度暴露在杀死从存活孢子发芽或烹饪后到达食物的微生物方面具有可变的影响,但是热稳定的毒素不会被灭活。