title: Combined Effect of Thermosonication and Slightly Acidic Electrolyzed Water to Reduce Foodborne Pathogens and Spoilage Microorganisms on Fresh-cut Kale.
abstract: This study evaluated the efficacy of individual treatments (thermosonication [TS+DW] and slightly acidic electrolyzed water [SAcEW]) and their combination on reducing Escherichia coli O157:H7, Listeria monocytogenes, and spoilage microorganisms (total bacterial counts [TBC], Enterobacteriaceae, Pseudomonas spp., and yeast and mold counts [YMC]) on fresh-cut kale. For comparison, the antimicrobial efficacies of sodium chlorite (SC; 100 mg/L) and sodium hypochlorite (SH; 100 mg/L) were also evaluated. Each 10 g sample of kale leaves was inoculated to contain approximately 6 log CFU/g of E. coli O157:H7 or L. monocytogenes. Each inoculated or uninoculated samples was then dip treated with deionized water (DW; control), TS+DW, and SAcEW at various treatment conditions (temperature, physicochemical properties, and time) to assess the efficacy of each individual treatment. The efficacy of TS+DW or SAcEW was enhanced at 40 °C for 3 min, with an acoustic energy density of 400 W/L for TS+DW and available chlorine concentration of 5 mg/L for SAcEW. At 40 °C for 3 min, combined treatment of thermosonication 400 W/L and SAcEW 5 mg/L (TS+SAcEW) was more effective in reducing microorganisms compared to the individual treatments (SAcEW, SC, SH, and TS+DW) and combined treatments (TS+SC and TS+SH), which significantly (P < 0.05) reduced E. coli O157:H7, L. monocytogenes, TBC, Enterobacteriaceae, Pseudomonas spp., and YMC by 3.32, 3.11, 3.97, 3.66, 3.62, and >3.24 log CFU/g, respectively. The results suggest that the combined treatment of TS+SAcEW has the potential as a decontamination process in fresh-cut industry.
authors.affiliation: Dept. of Food Science and Biotechnology, School of Bioconvergence Science and Technology, Kangwon National Univ., Chuncheon, Gangwon, 200-701, Republic of Korea.
authors.forename: Ahmad Rois
authors.initials: AR
authors.lastname: Mansur
authors.affiliation: Dept. of Food Science and Biotechnology, School of Bioconvergence Science and Technology, Kangwon National Univ., Chuncheon, Gangwon, 200-701, Republic of Korea.
authors.forename: Deog-Hwan
authors.initials: DH
authors.lastname: Oh
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001937:Brassica / Q000382:microbiology*; D002713:Chlorine / Q000494:pharmacology; D015169:Colony Count, Microbial; D004572:Electrolysis; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013010:Sonication; D000069453:Ultrasonic Waves; D014867:Water / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D014867:Water; D002713:Chlorine; D012973:Sodium Hypochlorite
keywords: fresh-cut kale; pathogenic bacteria; slightly acidic electrolyzed water; spoilage microorganisms; thermosonication