短波紫外线照射对鲜切菠萝微生物的影响

Effect of UV-C Irradiation on Microbial Indexes of Fresh-cut Pineapples

为研究短波紫外线照射对鲜切菠萝中微生物的影响,采用表皮半黄成熟度的菠萝为原料进行鲜切加工,在波长254nm短波紫外线下用不同时间照射处理,结果表明:在照射15s以上时,整个贮藏期均未检测出大肠菌群;照射时间在90s时,到贮藏末期霉菌数为2.9×105CFU/g、酵母菌为对照组含量的9.6%,而照射时间60s对菌落总数抑制最明显为2.4×105CFU/g。说明经过短波紫外照射可以明显杀灭鲜切菠萝中大肠菌群,60～90s时可以显著降低菠萝中霉菌、酵母菌以及菌落总数的含量。

Fresh-cut pineapples processed from part yellow ones were irradiated by UV-C at 254 nm to study the effects of UV-C on their various microbial indexes. No coliform was detected from the fresh-cut pineapples irradiated for more than 15 s over the whole storage period. The mold count of the fresh-cut pineapples irradiated for 90 s was 2.9 ×10^5 CFU/g and the yeast count was 9.6% of that of the control group. The irradiation for 60 s exhibited the most marked inhibition effect on the total colony count of fresh-cut pineapples which was 2.4 ×10^5 CFU/g on the 11th day of storage. The results showed that UV-C irradiation is able to effectively kill the coliform in fresh-cut pineapples and the counts of mold, yeast and total colony can be reduced distinctly by UV-C irradiation for 60 -- 90 s.