title: Interactions of nisin with glutathione in a model protein system and meat.
abstract: Loss of nisin activity in meat has been ascribed, in part, to the formation of a nisin-glutathione adduct. Activity is lost more quickly in raw meat than in cooked meat, and this has been taken as evidence that the reaction is enzyme mediated. Formation of the nisin-glutathione adduct has been confirmed but is shown not to be enzyme mediated. Retention of activity in cooked meat is shown to be due to the loss of free sulfhydryl groups during cooking as a result of the reaction of glutathione with proteins and not a result of the inactivation of endogenous enzymes. Microbial enzymes do not appear to play a role, as similar losses are seen in raw and cooked meat extracts, both of which contained undetectable levels of microorganisms.
authors.affiliation: School of Biomedical and Molecular Sciences, University of Surrey, Guildford, United Kingdom.
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Stergiou
authors.forename: Linda V
authors.initials: LV
authors.lastname: Thomas
authors.forename: Martin R
authors.initials: MR
authors.lastname: Adams
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D003296:Cooking / Q000379:methods*; D004044:Dietary Proteins / Q000032:analysis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005978:Glutathione / Q000494:pharmacology*; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D008460:Meat / Q000382:microbiology* / Q000592:standards; D009561:Nisin / Q000493:pharmacokinetics / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D004044:Dietary Proteins; D009561:Nisin; D005978:Glutathione