title: Effect of free-SH containing compounds on allyl isothiocyanate antimicrobial activity against Escherichia coli O157:H7.
abstract: Escherichia coli O157:H7 contamination is a significant meat safety issue in many countries. Allyl isothiocyanate (AIT) is a natural compound found to limit the survival of E. coli O157:H7 and other pathogens in meat and meat products. In the present study, it was found that glutathione and cysteine naturally present in meat can interfere with AIT antimicrobial activity. Spectroscopy, HPLC, and LC-MS were used to confirm that glutathione was able to react with AIT and formed a conjugate with no or low bactericidal activity against the tested organisms. The same reaction also occurred at pH values of 4.9 and 5.8 at 25 and 4 degrees C, respectively, which broadly represent storage conditions in raw beef (pH 5.8) and during fermented sausage (pH 4.9) manufacture. Reactions observed help to explain reduction in antimicrobial potency of AIT in food (meat) systems.
authors.affiliation: Department of Food Science, Faculty of Agricultural and Food Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: F B
authors.initials: FB
authors.lastname: Luciano
authors.forename: F S
authors.initials: FS
authors.lastname: Hosseinian
authors.forename: T
authors.initials: T
authors.lastname: Beta
authors.forename: R A
authors.initials: RA
authors.lastname: Holley
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003257:Consumer Product Safety; D003545:Cysteine / Q000494:pharmacology; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development; D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017879:Isothiocyanates / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008460:Meat / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D017879:Isothiocyanates; C004471:allyl isothiocyanate; D005978:Glutathione; D003545:Cysteine