ANTIMICROBIAL EFFECT OF COLD OZONATED WATER WASHING ON FRESH-CUT LETTUCE
A cold ozonated water wash treatment was assessed for its antimicrobial activity against natural microflora and spiked pathogenic bacteria on fresh-cut leafy lettuce. The strains used for this study were Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Listeria monocytogenes and Staphylococcus aureus. The cold ozonated water was prepared by dissolving gaseous ozone in cold water (2°C) made by an ice-slurry system. Tap water and chlorinated water (100 mg/L and 200 mg/L) were also treated and compared with ozonated water treatment (0 ~ 10 mg/L). All pathogenic bacteria decreased by 99% within 1 minute of treatment with 5 mg/L ozonated water. For total cell counts and coliform counts, 3 mg/L ozonated water was optimal by causing 3 ~ 4 log reduction, which was similar to the result achieved by 100 mg/L chlorinated water. This study suggests that cold ozonated water washing treatment can be a useful means for eliminating microorganisms on fresh-cut vegetables such as a lettuce in order to enhance microbiological safety.
Kim, B.S., Kwon, J.Y., Kwon, K.H., Cha, H.S., Jeong, J.W. and Kim, G.H. (2006). ANTIMICROBIAL EFFECT OF COLD OZONATED WATER WASHING ON FRESH-CUT LETTUCE. Acta Hortic. 699, 235-242
lettuce, fresh-cut, ozonated water washing, surface sterilization