波动温度条件下生鲜三文鱼中单增李斯特菌生长预测模拟

Predictive Modeling of the Growth of Listeria monocytogenes in Fresh Salmon under Dynamic Temperature Conditions

本研究旨在构建波动温度条件下三文鱼中单增李斯特菌的生长预测模型。将3株从三文鱼中分离的单增李斯特菌混合接种至无菌三文鱼样品,开展连续波动温度(1~35℃)条件下的生长试验。采用动态一步法对其中3组生长数据进行分析,构建包含初级模型(Huang模型、Baranyi和Two-compartment模型)与二级模型(HSR模型)的联合模型。结果表明:Huang-HSR模型、Baranyi-HSR模型和Two-compartment-HSR模型具有同等的拟合效果,由其预测的单增李斯特菌最低生长温度分别为0.51,1.21,1.20℃,最大生长浓度分别为9.41,9.35,9.36 lg(CFU/g)。基于模型对迟滞期的定义以及模型表达式的简洁程度,建议选择Huang-HSR模型来描述三文鱼中单增李斯特菌的生长。通过另设的波动温度生长试验及文献报道的恒定温度生长数据对Huang-HSR模型进行验证,波动温度和恒定温度生长数据的均方根误差(RMSE)分别在0.29~0.59 lg(CFU/g)和0.28~0.85 lg(CFU/g)范围,表明该模型适用于描述三文鱼中单增李斯特菌的生长行为。将构建的模型用于正弦波动温度条件下单增李斯特菌的生长模拟,以展示其潜在应用价值。本研究构建的数学模型可用于三文鱼中单增李斯特菌的动态生长预测。

The objective of this study was to develop growth prediction models of Listeria monocytogenes in salmon under fluctuating temperatures. A three-strain cocktail of Listeria monocytogenes isolated from salmon was inoculated to sterile salmon to perform dynamic(1-35 ℃) studies. The growth data collected from 3 independent temperature profiles were used to determine the kinetic parameters and construct a growth model combining the primary model(Huang Baranyi and Two-compartment model) and secondary model(HSR model) using a one-step kinetic analysis method. The results showed that Huang-HSR model, Baranyi-HSR model and Two-compartment-HSR model had an equal goodness of fit.The minimum growth temperature of Listeria monocytogenes estimated by the above three models were 0.51, 1.21 ℃ and1.20 ℃, respectively, and the maximum growth concentration were 9.41, 9.35, 9.36 lg(CFU/g). Based on the definition of the lag time in models and the conciseness of models expression, Huang-HSR model was suggested to describe the growth of Listeria monocytogenes in salmon. Huang-HSR model was then validated by the newly designed dynamic growth experiments and isothermal growth data from literature. The RMSE calculated by Huang-HSR model was both between0.29-0.59 lg(CFU/g) under dynamic conditions;while the RMSE was between 0.28-0.85 lg(CFU/g) for the model under constant temperatures, indicating Huang-HSR model can be used to describe the growth behavior of Listeria monocytogenes in salmon. The models were then used to simulate the growth of Listeria monocytogenes under a variety of continuous sine-wave temperature profiles to demonstrate its potential application. The mathematical models developed in this study can be used to predict the dynamic growth of Listeria monocytogenes in salmon under fluctuating temperatures.