厨房における細菌の常在化過程の追跡と機器取手を介した二次汚染リスクの低減

抄録

The secondary contamination during/after cooking is one of the causes of food poisoning. In order to prevent the occurrence of such incidents, it is necessary to identify locations where microorganisms are likely to adhere in food manufacturing facilities, and to efficiently remove them. In this study, we obtained aerobic plate count of 22 locations in a university’s food manufacturing training room in a total of 9 times to identify locations where microorganisms are likely to adhere. The median number of bacteria was 1.78 log cfu/100 cm² on the flat surface, while it was 2.12 log cfu/100 cm² on the handle, confirming that the number of bacteria on the handle was significantly higher (p < 0.05). Next, amplicon analysis was performed on the blast chiller handle where the highest number of viable bacteria was detected, and the contamination route was clarified. It was suggested that the bacteria that had been attached to the bean seedlings and sprouts may have been transmitted by the hands and attached to the handles. Finally, we investigated the effects of slightly acidic electrolyzed water used for cleaning manufacturing equipment. The log reduction value for the wiping solution was 0.098 to 0.31 log cfu, whereas that for isolated bacteria of the solution was 3.9 to 4.2 log cfu, suggesting the presence of a substance in the wiping solution that inhibits the action of electrolyzed water. These results suggest that it is desirable to monitor the sanitary conditions of handles, and to perform two-step cleaning using electrolyzed water, in order to prevent secondary contamination.