title: Isolation and identification of oxidation products of syringol from brines and heated meat matrix.
abstract: In this study we developed new extraction and detection methods (using HPLC-UV and LC-MS), making it possible to analyze the smoke phenol syringol and its oxidation products nitrososyringol, nitrosyringol, and the syringol dimer 3,3',5,5'-tetramethoxy-1,1'-biphenyl-4,4'-diol, which were identified in heated meat for the first time. Preliminary brine experiments performed with different concentrations of ascorbic acid showed that high amounts of this antioxidant also resulted in almost complete degradation of syringol and to formation of the oxidation products when the brines were heated at low pH values. Heat treatment (80°C) and subsequent simulated digestion applied to meat samples containing syringol, ascorbic acid and different concentrations of sodium nitrite produced 3,3',5,5'-tetramethoxy-1,1'-biphenyl-4,4'-diol even at a low nitrite level in the meat matrix, while nitroso- and nitrosyringol were isolated only after the digestion experiments. Increasing amounts of oxygen in the meat matrix decreased the syringol concentration and enhanced the formation of the reaction products in comparison to the samples without added oxygen.
authors.affiliation: Department of Analytical Chemistry, Institute of Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173 Hannover, Germany.
authors.forename: Sarah-Maria
authors.initials: SM
authors.lastname: Bölicke
authors.affiliation: Department of Analytical Chemistry, Institute of Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173 Hannover, Germany. Electronic address: waldemar.ternes@tiho-hannover.de.
authors.forename: Waldemar
authors.initials: W
authors.lastname: Ternes
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification*; D001205:Ascorbic Acid / Q000032:analysis; D001713:Biphenyl Compounds; D002417:Cattle; D005511:Food Handling; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008460:Meat; D008461:Meat Products / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D017711:Nonlinear Dynamics; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000302:isolation & purification; D000069466:Red Meat / Q000032:analysis*; D012492:Salts / Q000737:chemistry; D013552:Swine
chemical_list: C000618871:3,3',5,5'-tetramethoxy-1,1'-biphenyl-4,4'-diol; D000975:Antioxidants; D001713:Biphenyl Compounds; D009573:Nitrites; D012492:Salts; C017082:brine; D011748:Pyrogallol; C010120:pyrogallol 1,3-dimethyl ether; D001205:Ascorbic Acid
keywords: Ascorbic acid; Cured and heated meat; Curing brine; Oxidation products; Simulated digestion; Syringol