title: Efficacy of washing with hydrogen peroxide followed by aerosolized antimicrobials as a novel sanitizing process to inactivate Escherichia coli O157:H7 on baby spinach.
abstract: Aerosolization was investigated as a potential way to apply allyl isothiocyanate (AIT), hydrogen peroxide (H(2)O(2)), acetic acid (AA) and lactic acid (LA) on fresh baby spinach to control Escherichia coli O157:H7 during refrigeration storage. In this study, baby spinach leaves were dip-inoculated with E. coli O157:H7 to a level of 6 log CFU/g and stored at 4°C for 24 h before treatment. Antimicrobials were atomized into fog-like micro-particles by an ultrasonic nebulizer and routed into a jar and a scale-up model system where samples were treated. Samples were stored at 4°C for up to 10 days before the survival of the cells was determined. A 2-min treatment with 5% AIT resulted in a >5-log reduction of E. coli O157:H7 on spinach after 2 days refrigeration regardless if the samples were pre-washed or not; however, this treatment impaired the sensory quality of leaves. Addition of LA to AIT improved the antimicrobial efficacy of AIT. In the jar system, washing with 3% H(2)O(2) followed by a 2-min treatment of 2.5% LA+1% AIT or 2.5% LA+2% AIT reduced E. coli O157:H7 population by 4.7 and >5 log CFU/g, respectively, after 10 days refrigeration. In the scale-up system, up to 4-log reduction of bacterial population was achieved for the same treatments without causing noticeable adverse effect on the appearance of leaves. Thus, this study demonstrates the potential of aerosolized AIT+LA as a new post-washing intervention strategy to control E. coli O157:H7 on baby spinach during refrigeration storage.
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
authors.forename: Yaoxin
authors.initials: Y
authors.lastname: Huang
authors.forename: Mu
authors.initials: M
authors.lastname: Ye
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Chen
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000336:Aerosols; D000890:Anti-Infective Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004202:Disinfectants / Q000494:pharmacology*; D004926:Escherichia coli; D019453:Escherichia coli O157 / Q000187:drug effects*; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D017879:Isothiocyanates; D019344:Lactic Acid / Q000494:pharmacology; D012034:Refrigeration; D018724:Spinacia oleracea / Q000382:microbiology*
chemical_list: D000336:Aerosols; D000890:Anti-Infective Agents; D004202:Disinfectants; D017879:Isothiocyanates; D019344:Lactic Acid; D006861:Hydrogen Peroxide; C004471:allyl isothiocyanate; D019342:Acetic Acid