A Predictive Model of Different Temperature Growth of Escherichia Coli in Freshcut Lettuce Based on Matlab 7.0

摘要

Contamination of Escherichia coli in fresh-cut lettuce poses potential risk to the public. In order to study the growth characteristics of Escherichia coli 1.1187, we established a prediction model of different temperature growth of Escherichia coli in fresh-cut lettuce based on Matlab 7.0. In this study, the prediction model can well forecast the dynamic growth of Escherichia coli 1.1187 in fresh-cut lettuce, and it provides a rapid and effective method for safety assessment of fresh-cut lettuce during storage. The growth state of Escherichia coli 1.1187 was analyzed at different temperatures (4°C, 11°C, 19°C, 27°C and 35°C). The primary prediction model was established by modified the Gompertz equation. The secondary prediction model was established by square root equation. Then the model was verified at different temperatures (22°C and 30°C). Experimental results showed that the primary prediction model fitting correlation coefficient is above 0.99, the bias factor and accuracy factor of secondary model are in the range of 0.90 and 1.05. At 4°C, Escherichia coli 1.1187 growth was restrained dramatically, so it is impossible for fitting by modified the Gompertz equation. In this study, we obtained the low growth temperature and the optimum growth temperature of E.coli 1.1187 were 7.03°C and 17.52°C respectively.