Reduction of Poliovirus 1, Bacteriophages, Salmonella Montevideo, and Escherichia coli O157:H7 on Strawberries by Physical and Disinfectant Washes,

Abstract

The efficacy levels of different physical and chemical washing treatments in the reduction of viral and bacterial pathogens from inoculated strawberries were evaluated. Escherichia coli O157:H7, Salmonella Montevideo, poliovirus 1, and the bacteriophages PRD1, phiX174, and MS2 were used as model and surrogate organisms. Chemicals readily available to producers and/or consumers were evaluated as antimicrobial additives for the production of washes. The gentle agitation of contaminated strawberries in water for 2 min led to reductions in microbial populations ranging from 41 to 79% and from 62 to 90% at water temperatures of 22 and 43 degrees C, respectively. Significant reductions (> 98%) in numbers of bacteria and viruses were obtained with sodium hypochlorite (50 to 300 ppm of free chlorine), Oxine or Carnebon (200 ppm of product generating "stabilized chlorine dioxide"), Tsunami (100 ppm of peroxyacetic acid), and Alcide (100 or 200 ppm of acidified sodium chlorite) washes. Overall, 200 ppm of acidified sodium chlorite produced the greatest reductions of microorganisms. Hydrogen peroxide (0.5%) was slightly less effective than free chlorine in a strawberry wash and caused slight fruit discoloration. Cetylpyridinium chloride (0.1%) was effective in the reduction of bacterial species, while trisodium phosphate (1%) was effective against viruses. The consumer-oriented produce wash Fit was very effective (> 99%) in reducing the numbers of bacteria but not in reducing the numbers of viruses. Another wash, Healthy Harvest, was significantly less effective than Fit in reducing bacterial pathogens but more effective for viruses. The performance of automatic dishwashing detergent was similar to that of Healthy Harvest and significantly better than that of liquid dishwashing detergent. Solutions containing table salt (2% NaCl) or vinegar (10%) reduced the numbers of bacteria by about 90%, whereas only the vinegar wash reduced the numbers of viruses significantly (ca. 95%).

Scientific Opinion on the risk posed by pathogens in food of non‐animal origin. Part 2 (Salmonella and Norovirus in berries)

“…Washing raspberries and strawberries was shown to result in approximately 1 log 10 cfu/g reduction in a mixture of five serovars of Salmonella enterica (Agona, Baildon, Gaminara, Michigan, and Montevideo) (Bialka and Demirci, 2007b). Similar results from washing alone were reported by Lukasik et al (2003) for Salmonella enterica serovar Montevideo inoculated onto strawberries. A slight increase in the effect of washing on reducing Salmonella contamination of strawberries was reported after the addition of sanitizing agents into the washing process (Raiden et al, 2003).…”

“…The different experimental set up of these studies also makes the comparison between different studies difficult. Lukasik et al (2003) reported the effect of different treatments against Salmonella enterica serovar Montevideo at 10 7 /ml inoculated onto strawberries. Reductions of almost 2 log units (>98 %) in numbers of Salmonella were obtained with sodium hypochlorite (50 to 300 ppm of free chlorine), "stabilized chlorine dioxide" (200 ppm), peroxyacetic acid (100 ppm), and acidified sodium chlorite (100 or 200 ppm) (Lukasik et al, 2003).…”

Application of Acidified Sodium Chlorite Prewashing Treatment to Improve the Food Hygiene of Lightly Fermented Vegetables

“…Application of the bactericidal effect of ASC for surface washing of raw salmon 52 , beef carcass 11 , and broiler carcasses 26 has been studied. However, only a few studies have been performed to apply the bactericidal effect of ASC for the surface washing of raw vegetables or fruits 18,34 . We constructed a sensitive detection system for injured bacteria 20 and evaluated the effectiveness of ASC in killing E. coli O157:H7 on leafy vegetables with a view to its potential application to foods and food contact surfaces as an anti-microbial treatment 22 .…”

Ultrastructure changes induced by dry film formation of a trisodium phosphate blend, antimicrobial solution

“…Its antimicrobial effectiveness has been demonstrated in bacteria, including the pathogenic Escherichia coli O157:H7 (Kim and Slavik 1994), Salmonella typhimurium (Kim and Slavik 1994), Listeria monocytogenes (Capita et al 2003), poliovirus (Lukasik et al 2003), and the yeast Yarrowia lipolytica (Ismail et al 2001). Trisodium phosphate has been reported in use at low to relatively high concentrations up to 12%.…”