Røssvoll Elin, Rønning Helene Thorsen, Granum Per Einar, Møretrø Trond, Hjerpekjøn Marianne Røine, Langsrud Solveig
Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway.
Norwegian University of Life Sciences, School of Veterinary Science, P.O. Box 5003, NO-1432 Ås, Norway.
Int J Food Microbiol. 2014 Aug 18;185:82-92. doi: 10.1016/j.ijfoodmicro.2014.05.020. Epub 2014 Jun 2.
It is crucial for the quality and safety of ready-to-eat (RTE) foods to maintain the cold chain from production to consumption. The effect of temperature abuse related to daily meals and elevated refrigerator temperatures on the growth and toxin production of Bacillus cereus, Bacillus weihenstephanensis and Staphylococcus aureus and the growth of Listeria monocytogenes and Yersinia enterocolitica was studied. A case study with temperature loggings in the domestic environment during Easter and Christmas holidays was performed to select relevant time and temperature courses. A model for bacterial surface growth on food using nutrient agar plates exposed to variations in temperatures was used to simulate food stored at different temperatures and exposed to room temperature for short periods of time. The results were compared with predicted growth using the modeling tool ComBase Predictor. The consumers exposed their cold cuts to room temperatures as high as 26.5°C with an average duration of meals was 47 min daily for breakfast/brunch during the vacations. Short (≤ 2 h) daily intervals at 25°C nearly halved the time the different pathogens needed to reach levels corresponding to the levels associated with human infection or intoxication, compared with the controls continuously stored at refrigerator temperature. Although the temperature fluctuations affected growth of both B. weihenstephanensis and S. aureus, toxin production was only detected at much higher cell concentrations than what has been associated with human intoxications. Therefore, growth of L. monocytogenes and Y. enterocolitica was found to be the limiting factor for safety. In combination with data on temperature abuse in the domestic environment, modeling programs such as ComBase Predictor can be efficient tools to predict growth of some pathogens but will not predict toxin production.
从生产到消费维持冷链对于即食（RTE）食品的质量和安全至关重要。研究了与日常膳食相关的温度滥用以及冰箱温度升高对蜡样芽孢杆菌、魏氏芽孢杆菌和金黄色葡萄球菌生长及毒素产生，以及单核细胞增生李斯特菌和小肠结肠炎耶尔森菌生长的影响。进行了一项案例研究，记录复活节和圣诞节假期期间家庭环境中的温度，以选择相关的时间和温度变化过程。使用暴露于温度变化的营养琼脂平板建立食品表面细菌生长模型，以模拟在不同温度下储存并短时间暴露于室温的食品。将结果与使用建模工具ComBase Predictor预测的生长情况进行比较。消费者在假期早餐/早午餐时将冷切肉暴露在高达26.5°C的室温下，每日用餐平均时长为47分钟。与持续储存在冰箱温度下的对照组相比，每天在25°C下短时间（≤2小时）间隔，不同病原体达到与人类感染或中毒相关水平所需的时间几乎减半。尽管温度波动影响了魏氏芽孢杆菌和金黄色葡萄球菌的生长，但仅在比与人类中毒相关的细胞浓度高得多时才检测到毒素产生。因此，发现单核细胞增生李斯特菌和小肠结肠炎耶尔森菌的生长是安全的限制因素。结合家庭环境中温度滥用的数据，ComBase Predictor等建模程序可以成为预测某些病原体生长的有效工具，但无法预测毒素产生。
