Department of Food Science and Technology, Faculty of Agriculture, Aristotle University of Thessaloniki 54124 Thessaloniki, Greece.
Oniris, INRAE, Secalim, Site de la Chantrerie, CS 40706, 44307 Nantes Cédex 3, France.
Food Res Int. 2023 Apr;166:112638. doi: 10.1016/j.foodres.2023.112638. Epub 2023 Feb 24.
Geobacillus stearothermophilus is one of the predominant spoilers of UHT-treated food products, due to its extremely heat-resistant spores. However, the surviving spores should be exposed to temperature higher than their minimum growth temperature for a certain time to germinate and grow to spoilage levels. Considering the projected temperature increase due to climate change, the events of non-sterility during distribution and transportation are expected to escalate. Hence, the aim of this study was to build a quantitative microbial spoilage risk assessment (QMRSA) model to quantify the risk of spoilage of plant-based milk alternatives within Europe. The model consists of four main steps: 1. Initial contamination of raw materials 2. Heat inactivation of spores during UHT treatment 3. Partitioning 4. Germination and outgrowth of spores during distribution and storage. The risk of spoilage was defined as the probability of G. stearothermophilus to reach its maximum concentration (N = 10 CFU/mL) at the time of consumption. The assessment was performed for North (Poland) and South (Greece) Europe, and the risk of spoilage was estimated for the current climatic conditions and a climate change scenario. Based on the results, the risk of spoilage was negligible for the North European region, while the risk of spoilage in South Europe was 6.2 × 10 95% CI (2.3 × 10;1.1 × 10) under the current climatic conditions. The risk of spoilage was increased for both tested countries under climate change scenario; from zero to 1.0 × 10 in North Europe, risk multiplied 2 or 3 in South Europe depending on air conditioning implementation at consumer's place. Therefore, the heat treatment intensity and the use of insulated trucks during distribution were investigated as mitigation strategies and led to significant reduction of the risk. Overall, the QMRSA model developed in this study can support risk management decisions of these products by quantify the potential risk under current climatic conditions and climate change scenarios.
嗜热脂肪地芽孢杆菌是超高温处理食品产品的主要腐败菌之一，因为它的孢子具有极强的耐热性。然而，存活的孢子应该暴露在高于其最低生长温度的温度下一定时间，才能发芽并生长到腐败水平。考虑到气候变化导致的预计温度升高，在分销和运输过程中出现无菌性事件的情况预计将会加剧。因此，本研究的目的是建立一个定量微生物腐败风险评估（QMRSA）模型，以量化欧洲植物性牛奶替代品的腐败风险。该模型由四个主要步骤组成：1. 原材料的初始污染 2. UHT 处理过程中孢子的热失活 3. 分配 4. 分销和储存过程中孢子的发芽和生长。腐败风险定义为在消费时达到最高浓度（N = 10 CFU/mL）的嗜热脂肪地芽孢杆菌的概率。评估分别针对北欧（波兰）和南欧（希腊）进行，根据当前气候条件和气候变化情景估计了腐败风险。基于结果，北欧地区的腐败风险可以忽略不计，而在当前气候条件下，南欧地区的腐败风险为 6.2×10 95%置信区间（2.3×10；1.1×10）。在气候变化情景下，两个测试国家的腐败风险都增加了；在北欧，从 0 增加到 1.0×10，在南欧，根据消费者所在地是否采用空调，风险增加了 2 倍或 3 倍。因此，研究中调查了热处理强度和在分销过程中使用隔热卡车作为减轻策略，这导致风险显著降低。总体而言，本研究中开发的 QMRSA 模型可以通过量化当前气候条件和气候变化情景下的潜在风险，为这些产品的风险管理决策提供支持。
