title: Inhibition of Listeria monocytogenes and Salmonella by combinations of oriental mustard, malic acid, and EDTA.
abstract: The antimicrobial activities of oriental mustard extract alone or combined with malic acid and EDTA were investigated against Salmonella spp. or Listeria monocytogenes at different temperatures. Five strain Salmonella or L. monocytogenes cocktails were separately inoculated in Brain Heart Infusion broth containing 0.5% (w/v) aqueous oriental mustard extract and incubated at 4 °C to 21 °C for 21 d. For inhibitor combination tests, Salmonella Typhimurium 02:8423 and L. monocytogenes 2-243 were individually inoculated in Mueller Hinton broth containing the mustard extract with either or both 0.2% (w/v) malic acid and 0.2% (w/v) EDTA and incubated at 10 °C or 21 °C for 10 to 14 d. Mustard extract inhibited growth of the L. monocytogenes cocktail at 4 °C up to 21 d (2.3 log10 CFU/mL inhibition) or at 10 °C for 7 d (2.4 log10 CFU/mL inhibition). Salmonella spp. viability was slightly, but significantly reduced by mustard extract at 4 °C by 21 d. Although hydrolysis of sinigrin in mustard extract by both pathogens was 2 to 6 times higher at 21 °C than at 4 °C to 10 °C, mustard was not inhibitory at 21 °C, perhaps because of the instability of its hydrolysis product (allyl isothiocyanate). At 21 °C, additive inhibitory effects of mustard extract with EDTA or malic acid led to undetectable levels of S. Typhimurium and L. monocytogenes by 7 d and 10 d, respectively. At 10 °C, S. Typhimurium was similarly susceptible, but combinations of antimicrobials were not more inhibitory to L. monocytogenes than the individual agents.
authors.affiliation: Dept. of Food Science, Faculty of Agriculture and Food Science, Univ. of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
authors.forename: Amin N
authors.initials: AN
authors.lastname: Olaimat
authors.forename: Richard A
authors.initials: RA
authors.lastname: Holley
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003470:Culture Media; D004492:Edetic Acid / Q000494:pharmacology*; D005516:Food Microbiology; D005961:Glucosinolates / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D017879:Isothiocyanates / Q000378:metabolism / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008293:Malates / Q000494:pharmacology*; D009149:Mustard Plant / Q000737:chemistry*; D028321:Plant Preparations / Q000494:pharmacology; D012475:Salmonella / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D005961:Glucosinolates; D017879:Isothiocyanates; D008293:Malates; D028321:Plant Preparations; C010330:sinigrin; C030298:malic acid; D004492:Edetic Acid; C004471:allyl isothiocyanate
keywords: EDTA; Listeria monocytogenes; Salmonella; malic acid; mustard; natural antimicrobials; sinigrin