储藏温度对侵入鲜切胡萝卜、黄瓜内部大肠杆菌生长的影响

Effect of storage temperature on the fate of internalized E. coli in fresh-cut carrots and cucumbers

为研究储藏温度对侵入鲜切蔬菜内部大肠杆菌生长的影响,以鲜切胡萝卜、黄瓜为原料浸泡接种大肠杆菌,分别置于4、12、24℃的条件下储藏,测定分析大肠杆菌在两种鲜切蔬菜中的侵入能力以及在储藏过程中的生长情况。结果表明,大肠杆菌能够侵入到鲜切胡萝卜、黄瓜内部。在4、12℃储藏过程中,侵入鲜切蔬菜内部的大肠杆菌数量随着储藏时间延长而逐渐降低（p〈0.05）。当储藏温度升高至24℃时,随着储藏时间的延长,侵入鲜切胡萝卜5~8 mm处的大肠杆菌缓慢下降,而侵入鲜切黄瓜内部不同深度大肠杆菌在储藏1~3 d无显著变化（p〉0.05）,在第5 d时略有下降。通过比较两种鲜切蔬菜中大肠杆菌的生长情况发现,在三种温度条件下储藏过程中,侵入鲜切黄瓜内部大肠杆菌的生长情况均优于侵入鲜切胡萝卜中的大肠杆菌。

In order to explore the effect of storage temperature on the fate of internalized E. coli in fresh-cut vegetables,fresh-cut carrots and cucumbers inoculated with E. coli and the stored at 4,12 and 24 ℃. The penetration ability of E. coli in these two kind of fresh-cut vegetable and the fate of internalized E. coli during storage were investigated. The results showed that E.coli could penetrate into fesh-cut carrots and cucumbers at varying degrees. During the storage at 4 and 12 ℃,the number of internalized E. coli was reduced gradually with storage time increased（p〈0.05）. When elevated storage temperature to 24 ℃,the populations of E. coli penetrated to 5~8 mm in fresh-cut carrots decreased during storage. While the couts of internalized E. coli in fresh-cut cucumbers at different depths did not change significantly（p〈0.05） during 3 d storage and decreased at the 5 d. Furthermore,the internalized E. coli in fresh-cut cucumbers grew better than that in fresh-cut carrots during storaged at 4,12 and 24 ℃.