鲜切水芹贮藏期间微生物生长模型及货架期预测

Microbial Growth Model and Shelf-Life Prediction of Fresh-Cut Cress during Storage

利用选择性培养基进行鲜切水芹贮藏期菌相分析,发现假单胞菌属是其贮藏期优势菌。保鲜袋挽口包装的鲜切水芹在22℃贮藏8 d,假单胞菌数量即达到106 CFU/g,低温贮藏有助于抑制假单胞菌的生长繁殖。修正的Gompertz模型能有效地拟合出4℃和22℃条件下假单胞菌属细菌的动态变化,偏差度和准确度分析表明所建立的模型是有效的。鲜切水芹于低温贮藏3 d后置于常温(22±1)℃贮藏时,叶绿素和木质素动态变化符合一级模型,在实际应用中,可根据腐败菌的生长速率来预测鲜切水芹的货架期。

Pseudomonas was found to be the dominant bacteria of fresh-cut cress during storage when microflora analysis of cress was performed using selective medium. Fresh-cut cress was packaged in sealed bags and then stored for 8 d at 22 ℃and the number of Pseudomonas reached 106 CFU/g. The results showed that low temperature storage inhibited the growth and reproduction of Pseudomonas. A modified Gompertz model could fit effectively the dynamic changes of Pseudomonascount at 4 and 22 ℃. The deviation factor and accurate factor showed that the model was effective. The dynamic changes of chlorophyll and lignin in fresh-cut cress during storage for 3 day at low temperature followed by at room temperature（22 ±1） ℃ could be fitted to a first-order kinetic model. The shelf-life of fresh-cut cress can be predicted according to the growthrate of spoilage bacteria in actual application.