| Abstract
| - Lipid oxidation and oxymyoglobin oxidation were measured in bovine muscle homogenates. M.longissimusdorsi homogenates (25% w/w, pH 5.7) were prepared, held at 4 °C, and subjected toone of the following treatments: (i) stirred and bubbled with oxygen, (ii) stirred with no oxygen, or (iii)neither stirred nor bubbled with oxygen (control). Lipid oxidation was initiated with 45 μM ferric chloride/sodium ascorbate. Lipid oxidation was highest and oxymyoglobin oxidation lowest in the homogenatebubbled with oxygen while lipid oxidation was lowest and oxymyoglobin oxidation highest in the controlhomogenate. Dissolved oxygen became depleted over time in the control homogenate, remainedhigh in the homogenate bubbled with oxygen, but decreased and then increased in the homogenatestirred with no oxygen. Free radical formation was lower in the control homogenate than in the stirredhomogenates as determined by spin trapping and electron spin resonance detection. The dataindicated that lipid oxidation-induced oxygen depletion, as opposed to primary or secondary lipidoxidation products, is a likely cause of oxymyoglobin oxidation in muscle systems. Keywords: Lipid; oxymyoglobin; oxidation; oxygen concentration; free radicals
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