气调保鲜冷却猪肉中假单胞菌最小检出生长时间模型的构建

Establishment of Time-to-detection Model of Pseudomonas spp. in Atmosphere Modified Packaged Chilled Pork

主要将气调保鲜冷却猪肉中的优势腐败菌之一的假单胞菌接种到灭菌肉上,在(4±1)℃条件下,通过运用线性回归方程构建不同气调比例下假单胞菌的最小检出生长时间(time-to-detection,TTD)模型。结果表明:假单胞菌的最小检出生长时间在无CO2的情况下,会随着O2体积分数的增加而减小;但会随着CO2体积分数的增加而增大。初始接种量的增大也会减小最小检出生长时间,但是当接种浓度大于102CFU/mL,减小并不明显。TTD模型的拟合度良好,回归系数(r2)高达0.959,实际观测值与模型预测值的判定系数R2均高于0.986,模型的偏差因子(Bf)和准确因子(Af),分别为1.012和1.086,均接近1。

This study was to establish a growth probability model of Pseudomonas spp.in atmosphere modified packaged chilled pork at（4 ± 1） ℃.Linear regression was used to establish TTD（time-to-detection） models of Pseudomonas spp.in different atmosphere conditions.Disinfected pock was inoculated with Pseudomonas spp.,a specific spoilage organisms in chilled pock.The results showed that in the absence of CO2,the TTD decreased with increasing O2 concentration,but increased as CO2 concentration increased.TTD reduced sharply as initial inoculation increased.However,no apparent decrease in TTD was found when initial inoculation was over 102 CFU/mL.The TTD models developed in this study showed a regression coefficient（r2） higher than 0.959 and the coefficients of determination（R2） for the observed versus predicted data were higher than 0.986.In addition,the Bf and Af for the TTD models were 1.012 and 1.086,respectively.Both were close to 1.