Interactions Between Carnosine and the Different Redox States of Myoglobin

To better understand the mechanism by which camosine inhibits myoglobin oxidation in salted ground pork, interactions of camosine with ferrylmyoglobin (ferMb), metmyoglobin (metMb) and oxymyoglobin (oxyMb) were investigated. Camosine (0–50 mM pH 5.0–7.5) accelerated the conversion of metMb to oxyMb at pH ≥ 7.0 and carnosine concentrations ≥ 25 mM. Camosine (1–50 mM) also accelerated the conversion of oxyMb to metMh with its formation rates increasing with decreasing pH and increasing camosine concentrations. Camosine (1–25 mM) inhibited ferMb‐catalyzed oxidation of phosphatidylcholine liposomes 16–76% and reduced the ferMh electron paramagnetic resonance signal 24–43%. Results suggested that the color stabilizing effects of camosine were related to its antioxidant activity.