Sterilization effect and influence on food surface by acidic electrolyzed water treatment

Recently, several reports about sterilization effect of electrolyzed water have been published. The electrolyzed water is expected as one of attractiv e application for sanitation of fresh food, however, to install this electr olyzed water, we have to clear the potential of the microorganism control f or real food. In this paper, we try to reveal the mechanism of the microorg anism control, and also try to check the food quality change during the tre atment. Therefore, to evaluate the effect of the electrolyzed water, we exa mined the several test for making sterilization mechanism clear and observe d microorganism behavior on food surface. At first, for the purpose of maki ng sterilization effects clear in vitro condition, we did microorganism tes t with several injection ratio and number. Then, we studied the effects of catalase on the enumeration of stressed Escherichia coli cells after acidic electrolyzed water treatment. Moreover, we studied sterilization effect of acidic electrolyzed water for E. coli on an agar block on the assumption a s one of food model. In addition, we studied sterilization effects for slic ed raw tuna as one sample of food surface treatment, The change in the qual ity of food surface was observed by scanning electron microscope, color met er and so on. Sterilization effects are dependent the condition of injectio n ratio and mixing numbers. These results suggest that it is important to k eep available chlorine concentration for keeping the potential to the micro organisms' control. The increasing of E. coli number with the addition of c atalase was suggested that the weak concentration of electrolyzed water gav e the injured microbes. The Observation of cultivated E. coli behavior on a gar block showed the microorganism behavior. Acidic electrolyzed water ster ilizes microorganisms on sliced raw tuna, however, after treatment, the col or change of surface of tuna and the protein denaturation were observed. Th ese results suggest that when the electrolyzed water treatment is applied t o control the microorganism on surface, the effect against food surface mus t be considered.