Effectiveness if different sanitizers to control Escherichia coli O157:H7 on tomato surfaces
Y. Inatsu, Md L. Bari, D. Nei, S. Kawasaki, and S. Kawamoto
Book of Abstracts, Southeast Asia Symposium Quality and Safety of Fresh and Fresh Cut Produce Greater Mekong Subregion Conference on Postharvest Quality Management in Chains, August 3-5, 2009, Radisson Hotel, Bangkok, Thailand.
2009
บทคัดย่อ
The use of suitable sanitizer can contribute to reduce the risk of vegetable related foodborne illnesses. We evaluated the effectiveness of several sanitizers to reduce the inoculated Escherichia coli O157:H7 on petit (small) tomato surface. The difference of the effectiveness depending on the method of inoculation (dipping / spotting) was examined. Each of 80g of inoculated tomatoes was washed in 400 mL of sanitizer or water for 5 minutes. The obtained effectiveness of spot inoculated tomatoes was higher (2.0 log CFU/g) than those of dip inoculated samples. Washing with water or chlorine water could reduce 1.3 log CFU/g of E. coli O157:H7 in dip inoculated (6.7 log CFU/g) tomatoes. Washing with 1 g/L lactic acid, phytic acid, calcinated seashells (oyster / Sakhalin surf clam) and chitosan (in 0.5 g/L lactic acid) did not exhibit higher sanitary effectiveness than that of water wash alone (1.0 log CFU/g). Acidified sodium chlorite (ASC) solution prepared from 0.5 g/L of sodium chlorite and 5 g/L lactic or phytic acid reduced 3.5 log CFU/g of surface attached E. coli. The effectiveness of acidified sodium chloride was similar to that of water wash when the concentration of sodium chlorite was less than 0.05 g/l. Water or lactic acid (0.5 g/L) wash followed by a second wash with ASC (0.5 g/L of sodium chlorite and 5 g/L of lactic acid) did not exhibit additional sanitary effectiveness compare to single wash with ASC. However, washing with ASC followed by a second wash with 1 g/L chitosan (in 0.5 g/L lactic acid) exhibited additional 1.0 log CFU/g effectiveness compare to a secondary wash with up to 2 days of storage at 10°C. No significant difference of color, appearance, texture and taste was observed among all kinds of washed samples.