title: Myoglobin and haemoglobin-mediated lipid oxidation in washed muscle: observations on crosslinking, ferryl formation, porphyrin degradation, and haemin loss rate.
abstract: Reduced trout haemoglobin (Hb) is a mixture of oxy- and deoxy-Hb at pH 6.3. Addition of oxy/deoxyHb to washed muscle resulted in detectable ferryl Hb while adding bovine oxyHb, trout metHb, or bovine metHb did not. Trout metHb promoted lipid oxidation more rapidly than bovine metHb, attributable to lower haemin affinity in fish Hbs. Protoporphyrin IX degradation was prevalent during trout and bovine Hb-mediated lipid oxidation. Caffeic acid prevented porphyrin degradation and lipid oxidation. Crosslinked myoglobin (Mb) promoted lipid oxidation more effectively than metMb. Fish metMb released haemin more readily than mammalian metMb at pH 5.5. These studies suggest haemin dissociation from metHb causes formation of free radicals that degrade protoporphyrin and cause lipid oxidation, and appreciable quantities of deoxyHb are needed to generate ferryl Hb oxidant. Crosslinking appears to facilitate Mb-mediated lipid oxidation in washed muscle yet haemin release can occur from fish metMb at low pH.
authors.affiliation: Kangwon National University, Department of Animal Products & Food Science, Meat Science Laboratory, KNU Ave 1, Chuncheon, Gangwon 200-701, South Korea.
authors.forename: Sung Ki
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Department of Animal Sciences, Meat Science and Muscle Biology Laboratory, University of Wisconsin-Madison, Madison, WI 53706, United States.
authors.forename: Nantawat
authors.initials: N
authors.lastname: Tatiyaborworntham
authors.affiliation: Department of Animal Sciences, Meat Science and Muscle Biology Laboratory, University of Wisconsin-Madison, Madison, WI 53706, United States.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Grunwald
authors.affiliation: Department of Animal Sciences, Meat Science and Muscle Biology Laboratory, University of Wisconsin-Madison, Madison, WI 53706, United States. Electronic address: mprichards@ansci.wisc.edu.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Richards
mesh_terms: D000818:Animals; D002417:Cattle; D005399:Fishes / Q000378:metabolism; D006427:Hemin; D006454:Hemoglobins; D050356:Lipid Metabolism; D009211:Myoglobin / Q000032:analysis*; D014337:Trout
chemical_list: D006454:Hemoglobins; D009211:Myoglobin; D006427:Hemin
keywords: Beef; Fish; Haem pigments; Hypervalent species; Lipid oxidation; Rancidity