title: Effect of nitrosylmyoglobin and saturated fatty acid anions on metmyoglobin-catalyzed oxidation of aqueous methyl linoleate emulsions.
abstract: In aqueous methyl linoleate emulsions (pH 7.4, 25 degrees C, air-saturated), nitrosylmyoglobin and saturated fatty acid anions (palmitate and stearate investigated) each showed antioxidant effect on metmyoglobin-induced peroxidation as measured by oxygen depletion rate. For equimolar concentration of nitrosylmyoglobin and metmyoglobin and for metmyoglobin in moderate excess, a reduction in oxygen consumption rate of approximately 70% was observed. Fatty acid anions reduced oxygen consumption rate most significantly for palmitate (up to 60% for a fatty acid:heme protein ratio of 90:1). No further antioxidative effect was seen for fatty acid anions in the presence of nitrosylmyoglobin, whereas nitrosylmyoglobin showed a further antioxidant effect in presence of fatty acid anions in the metmyoglobin-catalyzed process. The antioxidative mechanism of nitrosylmyoglobin and fatty acid anions is different, and while the fatty acid anions seem active in inhibiting initiation of oxidation through protection against metmyoglobin activation into perferrylmyoglobin, as shown by freeze-quench Electron Spin Resonance (ESR) spectroscopy, nitrosylmyoglobin is rather active in the oxygen consuming (propagation) phase.
authors: Sect. Food Chemistry, Department of Dairy and Food Science, The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors: Jens K S
authors: JK
authors: Møller
authors: Laurette
authors: L
authors: Sosniecki
authors: Leif H
authors: LH
authors: Skibsted
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D004655:Emulsions; D005227:Fatty Acids / Q000737:chemistry*; D008041:Linoleic Acids / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D008786:Metmyoglobin / Q000737:chemistry*; D009211:Myoglobin / Q000031:analogs & derivatives* / Q000737:chemistry*; D018384:Oxidative Stress; D010101:Oxygen Consumption; D013997:Time Factors
chemical_list: D000975:Antioxidants; D004655:Emulsions; D005227:Fatty Acids; D008041:Linoleic Acids; D009211:Myoglobin; C031560:myoglobin nitroxide; D008786:Metmyoglobin; C005575:methyl linoleate