Nakanishi Yumiko, Kawamura Shiori, Tsutsuura Satomi, Shimamura Yuko, Murata Masatsune
Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan.
Biosci Biotechnol Biochem. 2013;77(6):1160-5. doi: 10.1271/bbb.120087. Epub 2013 Jun 7.
The aim of this study was to determine why food poisoning bacteria attached to cut cabbage are not efficiently disinfected by sodium hypochlorite (NaClO). Pretreatment of shredded cabbage with diethyl ether definitely decreased the survival numbers of Escherichia coli O157:H7 and Salmonella spp. after disinfection with 100 ppm of NaClO. The density of E. coli O157:H7 at the cut edge of a cabbage section was larger than that on the surface. The residual ratio of attached bacteria at the cut edge after NaClO disinfection was significantly higher than that on the surface. Microscopical observation indicated that the cut edge of shredded cabbage pretreated with diethyl ether was almost closed, resulting in a decrease in bacterial infiltration. Pretreatment of shredded cabbage with a higher concentration of NaClO to penetrate it more deeply significantly decreased the numbers of surviving bacteria after NaClO disinfection. Based on these results, we concluded that the bacteria attached to cut cabbage were not efficiently disinfected by NaClO, because not enough NaClO deeply infiltrated into the cut edges, and hence not enough came in contact with the bacteria.
本研究的目的是确定为什么附着在切碎卷心菜上的食物中毒细菌不能被次氯酸钠（NaClO）有效消毒。用乙醚预处理切碎的卷心菜确实能降低用100 ppm NaClO消毒后大肠杆菌O157:H7和沙门氏菌的存活数量。卷心菜切片切口边缘的大肠杆菌O157:H7密度大于其表面密度。NaClO消毒后，切口边缘附着细菌的残留率显著高于表面。显微镜观察表明，用乙醚预处理的切碎卷心菜的切口边缘几乎闭合，导致细菌渗透减少。用更高浓度的NaClO预处理切碎的卷心菜以使其渗透更深，显著降低了NaClO消毒后的存活细菌数量。基于这些结果，我们得出结论，附着在切碎卷心菜上的细菌不能被NaClO有效消毒，因为没有足够的NaClO深入渗透到切口边缘，因此与细菌接触的量不足。
