在对草莓的病源微生物污染调查中发现蜡样芽孢杆菌具有高的检出率。为比较不同温度和不同包装方式的草莓表面蜡样芽孢杆菌数量的变化情况，测定了7 ℃、15 ℃、25 ℃、30 ℃的温度条件下，采用保鲜盒包装和保鲜膜包装方式的草莓表面蜡样芽孢杆菌生长数据；选用Baranyi Roberts模型为初级模型，拟合不同温度和不同包装方式的草莓中蜡样芽孢杆菌生长曲线，并对模型进行验证。结果显示，7 ℃冷藏的蜡样芽孢杆菌均增长缓慢而与包装方式无关；15 ℃低温贮藏过程中，膜装与盒装延滞期基本相同，但膜装比盒装降低了0.7 lg cfu/g的生长势，说明保鲜膜在此温度下有一定的抑菌作用；在25 ℃、30 ℃储藏下两种包装方式的比生长速率和延滞期基本相同，蜡样芽孢杆菌在42 h后分别增长了2.9 lg cfu/g、3.2 lg cfu/g，表明贮藏温度是影响蜡样芽孢杆菌的主要因素。因此在高温条件下蜡样芽孢杆菌会带来潜在的食用安全风险。本研究结果为微生物定量风险评估提供重要信息。

The investigation of the pathogenic microbial contamination of strawberry revealed that Bacillus cereus had a high detection rate. To study the changes in the number of Bacillus cereus on the surface of strawberry at different temperatures and packaged using different methods, the growth of Bacillus cereus on the surface of the strawberries packaged in a crisper or wrapped with plastic wrap was measured at 7 ℃, 15 ℃, 25 ℃ and 30 ℃. The Baranyi Roberts model was used as the primary model to fit the growth curve of the Bacillus cereus in strawberries at different temperatures and with different packaging methods, followed by model verification. The results showed that the growth of the Bacillus cereus refrigerated at 7 ℃ was slow and independent on the packaging method. During the low temperature storage at 15 ℃, the lag periods for both packaging methods were essentially the same, but the growth decreased by 0.7 lg cfu/g in the case of membrane package compared with the case of using crispers, suggesting that the plastic wrap might exert a certain degree of antibacterial effect at this temperature. During the storage at 25 ℃ and 30 ℃, the specific growth rate and lag period were essentially the same for the two packaging methods, with an increase of 2.9 and 3.2 lg cfu/g, respectively, in the growth of Bacillus cereus after 42 h, indicating that storage temperature was the main factor affecting Bacillus cereus. Therefore, Bacillus cereus will bring potential safety risk of strawberry consumption under high temperature conditions. The results of this study provide important information for quantitative microbial risk assessment.

农业部农产品质量安全监管项目（风险评估（GJFP2019013））