Peeled whole onions (PWO) were cleaned at various hypochlorous acid (HA) concentration and steeping time and packed in LDPE bag keeping at 10℃ for 12 days and 35℃ for 3 days, in order eventually to examine microbiology, surface color and sensory quality. At the early stage of storage, it was found that total bacterial counts at H-II keeping at 10℃ after 1 minute steeping were 2.60 ± 0.18 log CFU/g, and those after 3 minutes steeping were 2.10 ± 0.18 log CFU/g which showed less than the control. The total bacterial counts at H-III were detected after 4 days. The total bacterial counts of PWO treated HA increased as steeping time became longer, HA concentration increased, and storage temperature went down. E. coli was not detected at all treatments. It was also found that during the treatment the L-value showed decreasing trend, but the parameter a- and b- value showed increasing trend. But these trends were mitigated as HA concentration increased. The result of sensory quality evaluation for the appearance showed that the sample stored with 10℃ gained higher evaluation than that with 10℃, while the control and H-III gained highest points significantly (p < 0.05) for the sample keeping at 10℃ after 12 days storage. The sensory odor of onion showed similar to that for the appearance, and the 8-day treatments of H-II and H-III showed no significantly difference (p < 0.05). On the basis of the results above, it is likely to be more effective to prolong the period of circulation of PWO if you use HA over 50 ppm for washing PWO and storage at 10℃. This study will contribute to improve safety and quality in circulation of PWO.

We evaluated the microbiological quality of a facility in which freshly cut onions were prepared. The total plate counts on walls, equipment, and raw materials were ND (not detected) to CFU/100 , CFU/100 , and CFU/g, respectively. No coliforms were detected on walls however, coliforms were detected at concentrations of ND to CFU/100 and CFU/g on equipment and raw materials, respectively. The total plate counts for falling and floating bacteria in the processing plant were ND to CFU/plate and , respectively. Pathogenic microorganisms such as Escherichia coli, Salmonella spp, Staphylococcus aureus, and Listeria monocytogenes were not detected on walls, equipment, or raw materials. Overall, the results of the study indicate that hygiene control at the fresh-cut processing plant should be improved.