Probabilistic Model for Listeria monocytogenes Growth during Distribution, Retail Storage, and Domestic Storage of Pasteurized Milk
Probabilistic Model for Listeria monocytogenes Growth during Distribution, Retail Storage, and Domestic Storage of Pasteurized Milk
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DOI：
10.1128/aem.02430-09
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发表时间：
2010-04-01
影响因子：
4.4
通讯作者：
Xanthiakos, Konstantinos
中科院分区：
文献类型：
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作者：
Koutsoumanis, Konstantinos;Pavlis, Athanasios;Xanthiakos, Konstantinos
对希腊巴氏杀菌奶在运输到零售、零售储存和国内储存和处理过程中的时间-温度条件进行了调查。来自调查的数据进行了描述与适当的概率分布，并引入到巴氏杀菌奶中的单核细胞增生李斯特菌的生长模型，考虑到应变的变异性进行了适当的修改。基于上述组成部分，应用概率模型来评估L。在巴氏杀菌奶的冷却链中使用蒙特卡罗模拟单核细胞增生。该模型预测，在市场上发布的44.8%的牛奶盒中，病原体将生长到消费时。对于这些产品，L的估计平均总生长量。在运输、零售储存和家庭储存期间，单核细胞增多症的第95次和第99次对数分别为0.93 log CFU和2.68 log CFU和4.01 log CFU。虽然根据欧盟法规2073/2005，希腊生产的巴氏杀菌奶属于不允许L。单核细胞增生李斯特氏菌由于保质期（法律规定）为5天，上述结果表明，这一保质期限制不能防止李斯特氏菌。单核细胞增多症在目前的冷链条件下生长。预测百分比的牛奶纸箱，最初污染1细胞/1升纸箱，其中病原体超过100细胞/毫升的安全标准，在消费时为0.14%。概率模型被用于冷冻链因素的重要性分析，使用等级顺序相关性，而选定的干预和保质期延长的情况进行了评估。结果表明，简单的干预措施，如从巴氏杀菌奶的家庭存储排除门架，可以有效地减少病原体的生长。门架是家用冰箱中最温暖的位置，也是消费者最常使用的巴氏杀菌奶的家用储存位置。此外，该模型预测，将这种干预与家用冰箱平均温度降低2 ℃相结合，可以将巴氏杀菌奶的保质期从5天延长到7天，而不会影响当前消费者对L.单核细胞增多症
A survey on the time-temperature conditions of pasteurized milk in Greece during transportation to retail, retail storage, and domestic storage and handling was performed. The data derived from the survey were described with appropriate probability distributions and introduced into a growth model of Listeria monocytogenes in pasteurized milk which was appropriately modified for taking into account strain variability. Based on the above components, a probabilistic model was applied to evaluate the growth of L. monocytogenes during the chill chain of pasteurized milk using a Monte Carlo simulation. The model predicted that, in 44.8% of the milk cartons released in the market, the pathogen will grow until the time of consumption. For these products the estimated mean total growth of L. monocytogenes during transportation, retail storage, and domestic storage was 0.93 log CFU, with 95th and 99th percentiles of 2.68 and 4.01 log CFU, respectively. Although based on EU regulation 2073/2005 pasteurized milk produced in Greece belongs to the category of products that do not allow the growth of L. monocytogenes due to a shelf life (defined by law) of 5 days, the above results show that this shelf life limit cannot prevent L. monocytogenes from growing under the current chill chain conditions. The predicted percentage of milk cartons-initially contaminated with 1 cell/1-liter carton-in which the pathogen exceeds the safety criterion of 100 cells/ml at the time of consumption was 0.14%. The probabilistic model was used for an importance analysis of the chill chain factors, using rank order correlation, while selected intervention and shelf life increase scenarios were evaluated. The results showed that simple interventions, such as excluding the door shelf from the domestic storage of pasteurized milk, can effectively reduce the growth of the pathogen. The door shelf was found to be the warmest position in domestic refrigerators, and it was most frequently used by the consumers for domestic storage of pasteurized milk. Furthermore, the model predicted that a combination of this intervention with a decrease of the mean temperature of domestic refrigerators by 2 C may allow an extension of pasteurized milk shelf life from 5 to 7 days without affecting the current consumer exposure to L. monocytogenes.