A pH-neutral electrolyzed oxidizing water significantly reduces microbial contamination of fresh spinach leaves

Food Microbiol. 2021 Feb:93:103614. doi: 10.1016/j.fm.2020.103614. Epub 2020 Aug 3.

Abstract

There are growing demands globally to use safe, efficacious and environmentally friendly sanitizers for post-harvest treatment of fresh produce to reduce or eliminate spoilage and foodborne pathogens. Here, we compared the efficacy of a pH-neutral electrolyzed oxidizing water (Ecas4 Anolyte; ECAS) with that of an approved peroxyacetic acid-based sanitizer (Ecolab Tsunami® 100) in reducing the total microbial load and inoculated Escherichia coli, Salmonella Enteritidis and Listeria innocua populations on post-harvest baby spinach leaves over 10 days. The impact of both sanitizers on the overall quality of the spinach leaves during storage was also assessed by shelf life and vitamin C content measurements. ECAS at 50 ppm and 85 ppm significantly reduced the bacterial load compared to tap water-treated or untreated (control) leaves, and at similar levels (approx. 10-fold reduction) to those achieved using 50 ppm of Ecolab Tsunami® 100. While there were no obvious deleterious effects of treatment with 50 ppm Tsunami® 100 or ECAS at 50 ppm and 85 ppm on plant leaf appearance, tap water-treated and untreated leaves showed some yellowing, bruising and sliming. Given its safety, efficacy and environmentally-friendly characteristics, ECAS could be a viable alternative to chemical-based sanitizers for post-harvest treatment of fresh produce.

Keywords: Baby spinach; Electrolyzed oxidizing water; Food safety; Foodborne pathogens; Peroxyacetic acid; Post-harvest sanitization.

MeSH terms

  • Bacteria / classification
  • Electrolysis*
  • Escherichia coli
  • Food Contamination / analysis*
  • Food Microbiology
  • Food Safety
  • Food Storage
  • Foodborne Diseases / microbiology
  • Hydrogen-Ion Concentration
  • Listeria
  • Oxidation-Reduction
  • Peracetic Acid
  • Plant Leaves / microbiology*
  • Salmonella enteritidis
  • Spinacia oleracea / microbiology*
  • Temperature
  • Water / chemistry*

Substances

  • Water
  • Peracetic Acid

Supplementary concepts

  • Listeria innocua