Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
Food Res Int. 2018 Sep;111:104-110. doi: 10.1016/j.foodres.2018.05.002. Epub 2018 May 7.
A predictive model for the effect of storage temperature on the growth of Geobacillus stearothermophilus was applied in order to assess the risk of evaporated milk spoilage in the markets of the Mediterranean region. The growth of G. stearothermophilus in evaporated milk was evaluated during a shelf life of one year based on historical temperature profiles (hourly) covering 23 Mediterranean capitals for five years over the period 2012-2016 obtained from the Weather Underground database (http://www.wunderground.com/). In total, 115 scenarios were tested simulating the distribution and storage conditions of evaporated milk in the Mediterranean region. The highest growth of G. stearothermophilus was predicted for Marrakech, Damascus and Cairo over the period 2012-2016 with mean values of 7.2, 7.4 and 5.5 log CFU/ml, respectively, followed by Tunis, Podgorica and Tripoli with mean growth of 2.8, 2.4 and 2.3 log CFU/ml, respectively. For the rest 17 capitals the mean growth of the spoiler was <1.5 log CFU/ml. The capitals Podgorica, Cairo, Tunis and Ankara showed the highest variability in the growth during the 5 years examined with standard deviation values for growth of 2.01, 1.79, 1.77 and 1.25 log CFU/ml, respectively. The predicted extent and the variability of growth during the shelf life were used to assess the risk of spoilage which was visualised in a geographical risk map. The growth model of G. stearothermophilus was also used to evaluate adjustments of the evaporated milk expiration date which can reduce the risk of spoilage. The quantitative data provided in the present study can assist the food industry to effectively evaluate the microbiological stability of these products throughout distribution and storage at a reduced cost (by reducing sampling quality control) and assess whether and under which conditions (e.g. expiration date) will be able to export a product to a country without spoilage problems. This decision support may lead to a significant benefit for both the competitiveness of the food industry and the consumer.
为了评估地中海地区市场中蒸发奶变质的风险，应用了一种预测储存温度对嗜热脂肪地芽孢杆菌生长影响的模型。根据 2012-2016 年期间从 Weather Underground 数据库（http://www.wunderground.com/）获得的 23 个地中海首都五年的历史温度曲线（每小时），评估了蒸发奶中嗜热脂肪地芽孢杆菌在一年保质期内的生长情况。总共测试了 115 种情景，模拟了地中海地区蒸发奶的分布和储存条件。在 2012-2016 年期间，马拉喀什、大马士革和开罗的嗜热脂肪地芽孢杆菌生长预测值最高，分别为 7.2、7.4 和 5.5 log CFU/ml，其次是突尼斯、波德戈里察和的黎波里，分别为 2.8、2.4 和 2.3 log CFU/ml。其余 17 个首都的变质菌平均生长值<1.5 log CFU/ml。在过去 5 年的研究中，波德戈里察、开罗、突尼斯和安卡拉的生长变异最大，增长率的标准差分别为 2.01、1.79、1.77 和 1.25 log CFU/ml。保质期内生长的预测范围和可变性用于评估变质风险，并以地理风险图的形式可视化。还使用嗜热脂肪地芽孢杆菌生长模型评估了调整蒸发奶保质期的方法，以降低变质风险。本研究提供的定量数据可以帮助食品行业在降低成本（通过减少抽样质量控制）的情况下，有效地评估这些产品在整个分销和储存过程中的微生物稳定性，并评估产品是否以及在哪些条件（例如保质期）下能够出口到一个没有变质问题的国家。这种决策支持可能会为食品行业的竞争力和消费者带来显著的利益。
