Use of Fulvic Acid or Sodium Silicate-Based Sanitizers to Inactivate L isteria monocytogenes , S almonella Typhimurium and P seudomonas aeruginosa on Food Contact Surfaces

Abstract

The objective of this study was to determine the efficacy of five fulvic acid-based and one sodium silicate-based sanitizers against Listeria monocytogenes, Salmonella Typhimurium DT104 and Pseudomonas aeruginosa on food contact surfaces. Minimum inhibitory concentration assays were conducted to determine the lowest effective concentration of sanitizers A, B, C, D, E and F against each bacterium. Stainless steel, high-density polyethylene, polyvinyl chloride and polycarbonate coupons were inoculated with the culture of one of the test organisms and dried for 1 h. The coupons were then sprayed with sanitizer A, B, C, E or F, and treated for 2 min. Samples were taken to enumerate the surviving organisms. The sanitizers reduced L. monocytogenes, S. Typhimurium and P. aeruginosa population by 2–6, 2.7–5.8 and 2–6 log cfu/coupon on food contact surfaces, respectively. In general, the tested sanitizers were the most effective on P. aeruginosa, followed by S. Typhimurium and then L. monocytogenes. Practical Applications Microorganisms attached to food contact surfaces can be a source of contamination of foods, leading to spoilage and food safety issues. Chemical disinfection with sanitizers is generally used to reduce the microbial contamination on food contact surfaces. Fulvic acid or sodium silicate-based sanitizers have been developed for use in food processing plants, but studies on the effects of these new sanitizers on food contact surfaces are limited. Our results demonstrated that sodium silicate-based sanitizer A and fulvic acid-based sanitizers B, C, E and F effectively reduced L. monocytogenes, S. Typhimurium and P. aeruginosa populations on stainless steel, high-density polyethylene, polyvinyl chloride and polycarbonate coupon surfaces. These results may help the food industry in selecting alternative sanitizers for cleaning food contact surfaces.