title: 4-methylcatechol inhibits protein oxidation in meat but not disulfide formation.
abstract: The interaction between phenolic compounds and protein thiols was investigated in minced beef with or without 500 ppm 4-methylcatechol (4-MC) that had been stored under oxygen or argon for 7 days (4 °C). Myofibrillar protein isolates were extracted, and the oxidative stability evaluated by the protein radical intensity measured by ESR spectroscopy was found to be improved by 4-MC as well as by storage without oxygen. Significant loss of thiols was found in samples stored under oxygen compared to argon, whereas an additional loss was found in samples with added 4-MC stored under oxygen. In beef with added 4-MC, LC-MS analysis showed formation of thiol-quinone adducts, which may explain the observed additional loss of thiols. Although storage without oxygen inhibited protein cross-link formation as evaluated by SDS-PAGE, both in presence and in the absence of 4-MC, no inhibitory effect of 4-MC was found on the formation of protein disulfide cross-links in beef stored under oxygen.
authors.affiliation: Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Sisse
authors.initials: S
authors.lastname: Jongberg
authors.forename: Marianne N
authors.initials: MN
authors.lastname: Lund
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Waterhouse
authors.forename: Leif H
authors.initials: LH
authors.lastname: Skibsted
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002396:Catechols / Q000494:pharmacology*; D002417:Cattle; D004220:Disulfides / Q000737:chemistry*; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D011809:Quinones / Q000032:analysis; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D000975:Antioxidants; D002396:Catechols; D004220:Disulfides; D009124:Muscle Proteins; D011809:Quinones; D013438:Sulfhydryl Compounds; C018599:4-methylcatechol