This study was designed to evaluate two triple-wash procedures with commercial antimicrobials to inactivate foodborne pathogens and surrogate bacteria on cucumbers and tomatoes. Fresh, West Virginia locally grown cucumbers and tomatoes were dip-inoculated with Salmonella Typhimurium and Tennessee, Listeria monocytogenes (3-strain), and Enterococcus faecium. Produce was washed through two triple-wash steps (10 s each) including water dip, antimicrobial dip, and water dip (WAW), or water dip, water dip, and antimicrobial dip (WWA), followed by draining (2 min) on aluminum foil. A triple-water (WWW) process was also included as a water-only control. Tested treatments were (1) water; (2) sodium hypochlorite (SH, 100 ppm, pH 8.2); (3) acidified sodium hypochlorite (ASH, 100 ppm, pH 6.8 adjusted by citric acid); (4) lactic and citric acid blend (LCA, 2.5%); and (5) a H₂O₂-peroxyacetic acid mix [SaniDate-5.0 (SD) 0.0064, 0.25, and 0.50%]. Surviving bacteria were recovered on xylose lysine tergitol-4 (XLT-4, Salmonella), Modified Oxford (MOX, L. monocytogenes), and bile esculin agar (E. faecium). Data (two replicates, four samples/replicate) were analyzed using the mixed model procedure of SAS (P = 0.05). Counts of Salmonella, L. monocytogenes, and E. faecium on unwashed cucumbers and tomatoes were 5.42–6.23, 6.31–6.92, and 6.05 log colony-forming units (CFU)/produce, respectively. Triple-wash with water only reduced all three tested bacteria by 0.45–1.36 log CFU/fruit. Triple-wash by WWA with antimicrobials achieved additional reductions [least squares means (LsMeans)] of 0.38 log CFU/cucumber (Salmonella), 0.56 log CFU/cucumber (E. faecium), 1.48 log CFU/tomato (Salmonella), 1.09 log CFU/tomato (L. monocytogenes), and 0.71 log CFU/tomato more than the WAW procedure. Applying SD-0.25 and SD-0.50% solutions in triple-washing cucumbers and tomatoes resulted in reductions (P > 0.05) similar to ASH and greater reductions (P < 0.05) than SH and LCA. E. faecium was less susceptible (P < 0.05) or there was no difference (P > 0.05) in comparison with Salmonella in most cases, except for tomatoes treated with WWA. The results of this study indicate that SD could be used as an alternative antimicrobial agent for chlorine water in triple-wash processing at local small produce plants. Future pilot plant validation studies and cost-effectiveness analyses are needed for applying SD solutions in triple-wash by WV local small produce growers.

This study aims to evaluate the microbiological quality and efficacy of antimicrobials to inactivate unstressed or cold-stress adapted Salmonella and

This study compared the quality variation and thermal inactivation of Escherichia coli O157:H7 in non-intact beef and veal. Coarse ground beef and veal patties (2.1 cm thick, 12.4 cm diameter, 180 g) inoculated with E. coli O157:H7, aerobically stored before double pan-broiling for 0–360 s without rest or to 55, 62.5, 71.1, and 76 °C (internal temperature) with 0.5- or 3.5-min rest. Microbial population and qualities including color, cooking losses, pH, water activity, fat, and moisture content, were tested. After cooking the beef and veal patties, the weight losses were 17.83–29%, the pH increased from 5.53–5.60 to 5.74–6.09, the moisture content decreased from 70.53–76.02% to 62.60–67.07%, and the fat content increased (p < 0.05) from 2.19–6.46% to 2.92–9.45%. Cooking beef and veal samples with increasing internal temperatures decreased a* and b* values and increased the L* value. Escherichia coli O157:H7 was more sensitive to heat in veal compared to beef with shorter D-value and “shoulder” time. Cooking to 71.1 and 76 °C reduced E. coli O157:H7 by >6 log CFU/g regardless of rest time. Cooking to 55 °C and 62.5 °C with a 3.5-min rest achieved an additional 1–3 log CFU/g reduction compared to the 0.5-min rest. Results should be useful for developing risk assessment of non-intact beef and veal products.