Added triacylglycerols do not hasten hemoglobin-mediated lipid oxidation in washed minced cod muscle.
Hemoglobin-mediated lipid oxidation in washed, minced cod muscle was related to the triacylglycerol to membrane lipid ratio. The same rapid development of thiobarbituric acid reactive substances (TBARS) and painty odor occurred with and without the presence of up to 15% menhaden oil. Without hemoglobin, development of TBARS and painty odor was slow, despite a high amount of hydroperoxides in samples with oil added (1135 micromol/kg muscle). This suggested that hemoglobin reacted by cleaving preformed hydroperoxides into secondary oxidation products. Nearly doubling the hemoglobin concentration approximately doubled the extent of lipid oxidation with and without added oil. This indicated that hemoglobin was limiting for the oxidation reaction. The noneffect of added oil suggests that membrane lipids and/or preformed membrane lipid hydroperoxides provided sufficient substrate in hemoglobin-catalyzed oxidation of washed minced cod muscle. Fe(2+-)ADP did not induce any oxidation of washed minced cod with/without added oil. Results suggest that lipid oxidation in fatty fish may be more related to the quantity and type of the aqueous pro-oxidant and the membrane lipids than to variations in total fat contents.
Undeland
Ingrid
I
Chalmers University of Technology, Department of Food Science, P.O. Box 5401, S-402 29 Göteborg, Sweden. ingrid.undeland@fsc.chalmers.se
Hultin
Herbert O
HO
Richards
Mark P
MP
D000818:Animals; D003080:Cold Temperature; D005395:Fish Oils / Q000008:administration & dosage; D005399:Fishes; D005524:Food Technology; D006454:Hemoglobins / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D015227:Lipid Peroxidation; D008563:Membrane Lipids / Q000032:analysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D009812:Odorants / Q000032:analysis; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D013997:Time Factors; D014280:Triglycerides / Q000008:administration & dosage*
D005395:Fish Oils; D006454:Hemoglobins; D008563:Membrane Lipids; D017392:Thiobarbituric Acid Reactive Substances; D014280:Triglycerides; C033266:Menhaden oil; D006861:Hydrogen Peroxide