Listeria monocytogenes在经高氧化还原电位酸性水处理的鲜食莴苣上预测模型的建立

Study on predictive model of the growth of Listeria monocytogenes in ready-to-eat lettuce treated with electrolyzed oxidizing water

采用高氧化还原电位酸性水(EOW)对接种过单核细胞增生李斯特菌的鲜食莴苣进行处理,研究残留菌在不同温度下的保存期限。建立Gompertz,Logistic和Baranyi初级模型,描述单增李斯特菌在不同温度下的生长情况,对比结果表明,Gompertz模型的判定系数R2=0.9913,能够更好地拟合李斯特菌在各个温度下的生长状况,并得到李斯特菌生长的Gompertz模型生长参数(SGR,LT,MPD)。利用平方根模型对其的最大比生长速率的平方根-温度进行拟合,得到莴苣上单核细胞增生李斯特菌生长的二级模型:SGR=0.015T+0.069。使用判定系数(R2)、均方误差(MSE)、偏差因子(BF)和准确因子(AF)对模型进行验证,结果表明,本研究得出的二级模型能够很好地预测单核细胞增生李斯特菌在相应环境下的生长状况。

The objective of this study was to observe the antimicrobial effect of electrolyzed oxidizing water （EOW） against Listeria monocytogenes in ready-to-eat lettuce, and develop predictive models of the growth kinetic of L.monocytogenes lettuce treated with EOW.Shelf life tests were done at seven different storage temperatures, and primary models （Gompertz,Logistic and Baranyi） were developed in order to find the best-fit model to describe the growth kinetic of L.monocytogenes.The comparison result indicated that Gompertz model could fit the growth kinetics of L .monocytogenes best at different temperatures with a high correlation coefficient value （R^2 = 0.9913）. The growth parameters （SGR, LT, MPD） were obtained using Gompertz model. Then SPSS was employed to develop the secondary model expressing the relations between square root of SGR and temperature：√SGR= 0.015T ＋0.069.Using the indices such as Mean Square Error （MSE）, Bias factor （BF）, Accuracy factor （AF） to validate the current model, the results demonstrated that the model developed was qualified enough to predict the growth of L.monocytogenes in practice in the future.