學生姓名:
魏靜盈
指導教授:
陳泰源
學期:
108上
摘 要:
Electrolyzed Oxidizing water (EO water) is widely used in food industry to inactivate microorganisms. However, the prospect of the formation of “viable but nonculturable” (VBNC) cells in pathogen after low free chlorine concentration (FCC) treatments under high organic loads presents safety concerns. For this study, we used neutral electrolyzed water (NEO) and acidic electrolyzed water (AEW) to induce E.coli O157:H7, Salmonella Enteritidis, Yersinia enterocolitica, Listeria monocytogenes into VBNC state. The concentration to develop VBNC state needed for NEO were 2.22 ppm and 4.44 ppm, while for AEW were 2.5 ppm and 1.25 ppm. The results also show that the increased concentration of both NEO and AEW can cause the reduction of microorganisms, for example it could not be detected while the concentration was more than 20 ppm and could be detected below 10 ppm. In the conclusion, either NEO or AEW can induced the pathogens into VBNC state while the concentration was less than 4 ppm. Both plating method and flow cytometry can be used to detect the present of VBNC microorganisms. However, the traditional plating method showed its limitation for identifying VBNC microorganisms, whereas flow cytometry can distinguish the physiological state of the microorganisms. Therefore, the combination of both methods could serve as a more reliable way to confirm the VBNC state of pathogens.
摘要 (3).pdf