MYOGLOBIN OXIDATION IN GROUND BEEF: MECHANISTIC STUDIES

ABSTRACT Antioxidants, citric acid and ascorbic acid did not affect the initial slow oxidation of myoglobin but extended the time before rapid oxidation began. NaCl increased the initial rate of pigment oxidation. Lipid extracted from freshly ground, lean beef increased the rate of myoglobin oxidation when added to freshly ground lean beef while lipid extracted from ground beef stored for 7 days did not. Added linoleic acid was more effective than trilinolein in promoting myoglobin oxidation. Lipase and lipoxygenase enhanced the rate of pigment oxidation while phospholipase A inhibited it. Oxalate inhibited both lipid and myoglobin oxidation and reversed the pro‐oxidant capacity of Fe +2 . EDTA also inhibited lipid oxidation but promoted myoglogin oxidation.