牛肉中单增李斯特菌的热失活模型

Thermal inactivation model of Listeria monocytogenes in ground beef

摘要:

摘要: 【目的】建立牛肉中单增李斯特菌的热失活动力学模型。【方法】将接种了3种不同血清型的单增李斯特菌混合菌液的牛肉分别在55℃、57.5℃、60℃、63℃、66℃和70℃进行热处理，在不同温度条件下单增李斯特菌数从109CFU?g-1下降至103CFU?g-1，其热失活曲线用修正的Gompertz模型进行了拟合；利用线性模型对单增李斯特菌的相对失活率（μ）和所持续时间（M）的自然对数值与温度（55－70℃）进行拟合；通过在59℃和64℃对牛肉中单增李斯特菌热处理，对所建的模型进行了验证。【结果】建立了牛肉中单增李斯特菌热失活动力学的一级模型和二级模型，经验证其准确因子和偏差因子均在可接受范围内。【结论】本研究所建立的模型能较好的模拟不同温度（55－70℃）对牛肉中单增李斯特菌热失活的影响。

Abstract:

Abstract: [Objective] To set up suitable kinetic models for the evaluation of heat inactivation rate of Listeria monocytogenes in ground beef. [Methods] Ground beef, inoculated with 3 strains of L. monocytogenes, was subjected to heating at 55℃, 57.5℃, 60℃, 63℃, 66℃ or 70℃ to develop the isothermal kinetic models. The survival curves were fitted with modified Gompertz model after the bacterial counts were decreased from 109CFU×g-1 to 103CFU×g-1. Natural logarithm of μ (the relative inactivation rate) and M (time constant) were fitted with linear regression model. The kinetic models were validated at 59℃ and 64℃. [Results] We established one first-level model and one secondary-level model to predict the inactivation rate. In addition, we validated the accuracy and deviation of the models to guarantee their feasibility. [Conclusion] The models should be suitable for describing the survival of L. monocytogenes in ground beef at different temperatures, which are helpful for the control of the pathogens.