鲜切小白菜和生菜不同贮藏温度下货架期预测模型的建立
Quality changes and construction of shelf life prediction model about microbial of fresh-cut leafy vegetables
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摘要: 为研究鲜切小白菜和鲜切生菜在贮藏期间的品质变化,并预测其货架期,本文以鲜切小白菜和鲜切生菜为研究对象,对其贮藏期间的感官品质、细菌总数和大肠菌群数变化进行研究,并以细菌总数为自变量对低温与室温下鲜切小白菜和生菜货架期预测模型进行拟合。结果显示,在4℃与25℃下贮藏时间分别为10 d与3 d时,两种蔬菜的感官评价均大于5分,超过了消费者接受范围,细菌总数和大肠菌群数也在该贮藏时间时超出了标准规定范围,得出鲜切小白菜和鲜切生菜在4℃与25℃下的货架期终点分别为10 d与3 d;低温与室温下鲜切小白菜和鲜切生菜货架期预测模型拟合结果分别为:SL4℃=lnln5.096/(N1-1.990)-1/0.279+7.452和SL25℃=lnln3.621/(N1-3.651)-1/1.124+1.512;两个预测模型的偏差因子分别为0.979和1.001,准确因子分别为1.050和1.040,表明所建立的模型是有效的。Abstract: In order to study the changes in the quality of fresh- cut cabbage and fresh- cut lettuce during storage and predict the shelf life,fresh- cut cabbage and fresh- cut lettuce were researched on their quality and microbial indicators,including colony- forming unit( CFU) and the number of coliform bacteria.With CFU as the independent variable,the shelf life prediction models at 4 ℃ and 25 ℃ were calculated. The results showed that when stored after 10 d and 3 d at 4 ℃ and 25 ℃ respectively,the quality evalution were reached at 5,which were unacceptable to consumers; and the number of total bacterial count and coliform bacteria beyond standards.According to these indicators,the shelf life were found out to be 10 d and 3 d at 4 ℃ and 25 ℃ separately. The shelf life prediction models at 4 ℃ and 25 ℃ were SL_(4℃)=ln{ln5.096/(N_1-1.990)}-1/0.279+7.452 and SL_(25℃)=ln{ln3.621/(N_1-3.651)-1/1.124+1.512,respectively.The deviation factor,0.979 and 1.001,and accurate factor,1.050 and 1.040,showed that the models were effective.They provided a theoretical basis for the calculation of shelf life of fresh- cut cabbage and fresh- cut lettuce.