Department of Nutrition and Dietetics, Istanbul Gedik University, 34876 Kartal, Istanbul, Turkey.
Department of Chemical Engineering, Gebze Technical University, 41400 Gebze, Kocaeli, Turkey.
Food Res Int. 2020 Apr;130:108912. doi: 10.1016/j.foodres.2019.108912. Epub 2019 Dec 18.
Baranyi model was fitted to experimental growth data of Pseudomonas spp. on the button mushrooms (Agaricus bisporus) stored at different isothermal conditions (4, 12, 20 and 28 °C), and the kinetic growth parameters of Pseudomonas spp. on the button mushrooms were obtained. The goodness of fit of the Baranyi model was evaluated by considering the root mean squared error (RMSE) and the adjusted coefficient of determination (adjusted-R). The Baranyi model gave RMSE values lower than 0.193 and adjusted-R values higher than 0.975 for all isothermal storage temperatures. The maximum specific growth rate (µ) was described as a function of temperature using secondary models namely, Ratkowsky and Arrhenius models. The Ratkowsky model described the temperature dependence of µ better than the Arrhenius model. Therefore, the differential form of the Baranyi model was merged with the Ratkowsky model, and solved numerically using the fourth-order Runge-Kutta method to predict the concentration of Pseudomonas spp. populations on button mushrooms under non-isothermal conditions in which they are frequently subjected to during storage, delivery and retail marketing. The validation performance of the dynamic model used was assessed by considering bias (B) and accuracy (A) factors which were found to be 0.998 and 1.016, respectively. The dynamic model developed also exhibited quite small mean deviation (MD) and mean absolute deviation (MAD) values being -0.013 and 0.126 log CFU/g, respectively. The modelling approach used in this work could be an alternative to traditional enumeration techniques to determine the number of Pseudomonas spp. on mushrooms as a function of temperature and time.
巴氏模型被拟合到在不同等温条件（4、12、20 和 28°C）下储存的双孢蘑菇（Agaricus bisporus）上的假单胞菌的实验生长数据，并且获得了假单胞菌在双孢蘑菇上的动力学生长参数。通过考虑均方根误差（RMSE）和调整后的决定系数（adjusted-R）来评估巴氏模型的拟合优度。对于所有等温储存温度，巴氏模型的 RMSE 值低于 0.193，adjusted-R 值高于 0.975。最大比生长速率（µ）被描述为二次模型，即 Ratkowsky 和 Arrhenius 模型，温度的函数。Ratkowsky 模型比 Arrhenius 模型更好地描述了µ的温度依赖性。因此，将巴氏模型的微分形式与 Ratkowsky 模型合并，并使用四阶龙格-库塔法数值求解，以预测在非等温条件下假单胞菌在双孢蘑菇上的种群浓度，因为它们在储存、运输和零售过程中经常会受到这种条件的影响。通过考虑偏差（B）和准确性（A）因素来评估所使用的动态模型的验证性能，发现它们分别为 0.998 和 1.016。所开发的动态模型还表现出相当小的平均偏差（MD）和平均绝对偏差（MAD）值，分别为-0.013 和 0.126 log CFU/g。本工作中使用的建模方法可以替代传统的计数技术，以确定温度和时间对双孢蘑菇上假单胞菌数量的影响。
