烤鸭中金黄色葡萄球菌生长动力学比较与动态模拟

Kinetic Comparison and Dynamic Simulation of the Growth of Staphylococcus aureus in Roasted Duck

金黄色葡萄球菌是危害烤鸭等熟肉制品食用安全的常见病原菌之一。本研究旨在考察不同贮藏温度条件下烤鸭中金黄色葡萄球菌的生长特性,构建并比较相关动态生长预测模型。将含有两株金黄色葡萄球菌的混合菌液接种至烤鸭样品,然后分别置于12,16,20,25,30和35℃条件下培养,测定其生长曲线。通过一步法对金黄色葡萄球菌的生长数据进行拟合分析,构建同时包含初级模型(Huang模型或Baranyi模型或Two Compartment模型)与二级模型(Huang Square Root,HSR模型)的组合生长模型。结果表明:Huang-HSR模型、Baranyi-HSR模型、Two Compartment-HSR模型具有同等的拟合效果,由3个组合模型估计的金黄色葡萄球菌的最低生长温度和最大生长浓度分别为8.29,8.74,8.74℃和9.31,9.32,9.32 lg(CFU/g)。通过另设的4组波动温度状态下烤鸭中金黄色葡萄球菌的生长试验,对Huang-HSR模型及参数进行验证,其RMSE介于(0.28~0.40)lg(CFU/g)范围,表明所构建的预测模型具有较高的准确度。结合实际采集的烤鸭店环境温度和人为设置的波动温度,通过Huang-HSR模型模拟金黄色葡萄球菌的动态生长,以证明其潜在的应用性。本研究构建的模型可用于烤鸭中金黄色葡萄球菌的生长预测。

Staphylococcus aureus is one of the common pathogens that threaten the food safety of roasted duck and other cooked meat products.The objective of this study was to investigate the growth characteristics of Staphylococcus aureus in roasted duck under different storage temperatures,then to develop and evaluate relevant dynamic models.The roasted duck samples inoculated with a 2-strain cocktail of Staphylococcus aureus were stored at 12,16,20,25,30 and 35℃,respectively,to observe the growth during storage.The one-step approach was used analyze the growth data of Staphylococcus aureus,and then to construct a combined growth model including the primary model(Huang model,Baranyi model,or Two Compartment model)and the secondary model(Huang Square Root(HSR)model).The results showed that Huang-HSR model,Baranyi-HSR model and Two Compartment-HSR model had an equal fitting effect.The minimum growth temperature and maximum cell density of Staphylococcus aureus estimated by the three combined models were 8.29,8.74,8.74℃,and 9.31,9.32,and 9.32 lg(CFU/g),respectively.The Huang-HSR model and its parameters were verified by the growth experiment of Staphylococcus aureus in roasted duck under another 4 groups of dynamic temperature profiles.The RMSE of the predicted value was between 0.28 and 0.40 lg(CFU/g),indicating that the prediction model constructed has high accuracy.The model was then used to simulate the dynamic growth of Staphylococcus aureus under real environmental temperature of roast duck restaurant and artificially set fluctuating temperatures to demonstrate its potential application.The models developed in this study can be used to predict the growth of Staphylococcus aureus in roasted duck.