Mathematical Models to Describe the Kinetic Behavior of Staphylococcus aureus in Jerky
Mathematical Models to Describe the Kinetic Behavior of Staphylococcus aureus in Jerky
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DOI：
10.5851/kosfa.2019.e28
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发表时间：
2019-01-01
影响因子：
3
通讯作者：
Yoon, Yohan
中科院分区：
文献类型：
--
作者：
Ha, Jimyeong;Lee, Jeeyeon;Yoon, Yohan
本研究的目的是建立数学模型来描述金黄色葡萄球菌（S。金黄色葡萄球菌）。将调味的牛肉干切成10 g的块。接下来，加入0.1 mL S.将金黄色葡萄球菌ATCC 13565接种到样品中以获得3LogCFU/g，并将样品在10 ℃、20 ℃、25 ℃、30 ℃和35 ℃下有氧储存600小时。S.在储存期间在Baird帕克琼脂上计数金黄色葡萄球菌细胞。为了开发一级模型，将Weibull模型拟合至细胞计数数据，以计算Delta（第一次小数减少所需的时间）和rho（曲线形状）。对于二次建模，将多项式模型拟合至作为储存温度函数的Delta值。为了评估模型预测的准确性，通过将预测数据与观测数据进行比较来计算均方根误差（RMSE）。幸存的S。金黄色葡萄球菌细胞计数在所有储存温度下均降低。Delta值在10 ℃、20 ℃和25 ℃下比在30 ℃和35 ℃下长。二级模型很好地描述了温度对Delta的影响，R-2值为0.920。在验证分析中，RMSE值为0.325，表明模型性能适当。S.牛肉干中金黄色葡萄球菌在低温下能存活很长时间，本研究建立的模型可用于描述金黄色葡萄球菌的动力学行为。调味牛肉干中的金黄色葡萄球菌。
The objective of this study was to develop mathematical models for describing the kinetic behavior of Staphylococcus aureus (S. aureus) in seasoned beef jerky. Seasoned beef jerky was cut into 10-g pieces. Next, 0.1 mL of S. aureus ATCC13565 was inoculated into the samples to obtain 3 Log CFU/g, and the samples were stored aerobically at 10 degrees C, 20 degrees C, 25 degrees C, 30 degrees C, and 35 degrees C for 600 h. S. aureus cell counts were enumerated on Baird Parker agar during storage. To develop a primary model, the Weibull model was fitted to the cell count data to calculate Delta (required time for the first decimal reduction) and rho (shape of curves). For secondary modeling, a polynomial model was fitted to the Delta values as a function of storage temperature. To evaluate the accuracy of the model prediction, the root mean square error (RMSE) was calculated by comparing the predicted data with the observed data. The surviving S. aureus cell counts were decreased at all storage temperatures. The Delta values were longer at 10 degrees C, 20 degrees C, and 25 degrees C than at 30 degrees C and 35 degrees C. The secondary model well-described the temperature effect on Delta with an R-2 value of 0.920. In validation analysis, RMSE values of 0.325 suggested that the model performance was appropriate. S. aureus in beef jerky survives for a long period at low storage temperatures and that the model developed in this study is useful for describing the kinetic behavior of S. aureus in seasoned beef jerky.