Effectiveness of acidified sodium chlorite and other sanitizers to control Escherichia coli O157:H7 on tomato surfaces.
The use of a suitable sanitizer can reduce the risk of produce-related foodborne illnesses. We evaluated the effectiveness of several sanitizers to reduce inoculated Escherichia coli O157:H7 on the surface of cherry tomatoes (Solanum lycopersicum var. cerasiform). Depending on the method of inoculation (dipping/spotting), each of 80 g (eight tomatoes) of inoculated cherry tomatoes was washed in 400 mL of sanitizer solutions or 400 mL distilled water for 5 minutes. The effectiveness of sanitizers on spot-inoculated E. coli O157:H7 on tomato surfaces was found higher than on dip-inoculated tomatoes. Washing with water or chlorine water (0.1 g/L as free chlorine) could reduce 1.3 log CFU/g of E. coli O157:H7 in dip-inoculated (6.8 log CFU/g) tomatoes. Washing with lactic acid (LA) solution (1.0 g/L), phytic acid solution (1.0 g/L), calcinated seashells (oyster/sakhalin surf clam), and 1.0 g/L chitosan in 0.5 g/L LA (Chito) did not exhibit a significant higher 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 1.0 g/L LA or phytic acid reduced 3.5 log CFU/g of E. coli O157:H7 in dip-inoculated tomato surfaces. ASC (0.5 g/L of sodium chlorite and 1.0 g/L of LA) wash followed by a second wash with LA exhibited an additional sanitary effectiveness compared to a single wash with ASC. However, washing with ASC followed by a second wash with Chito exhibited an additional 1.0 log CFU/g reduction compared to a secondary wash with water. No significant difference of color, taste, and texture was observed among the washed cherry tomatoes.
Inatsu
Yasuhiro
Y
National Food Research Institute, NARO, Tsukuba, Ibaraki, Japan. inatu@affrc.go.jp
Kitagawa
Tomoko
T
Bari
Md Latiful
ML
Nei
Daisuke
D
Juneja
Vijay
V
Kawamoto
Shinichi
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D055598:Chemical Phenomena; D048271:Chitosan / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000302:isolation & purification; D005517:Foodborne Diseases / Q000517:prevention & control; D005638:Fruit / Q000737:chemistry / Q000382:microbiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000737:chemistry / Q000382:microbiology*; D010833:Phytic Acid / Q000494:pharmacology; D010858:Pigmentation / Q000187:drug effects; D011786:Quality Control; D013499:Surface Properties; D013649:Taste
D000900:Anti-Bacterial Agents; D002712:Chlorides; D019344:Lactic Acid; D010833:Phytic Acid; D048271:Chitosan; C001599:chlorite