Evaluation of the antioxidant ability of hydrazine-purified and untreated commercial carnosine in beef patties

The aim of this research was to reevaluate the inhibition of oxidative changes in beef patties packaged in modified atmosphere (70% O-2 + 20% CO2 + 10% N-2) by carnosine (50 mM). The need for reevaluation was because it had been postulated that hydrazine present as contaminant in commercial carnosine could contribute to the antioxidant activity. Beef patties with either commercial or purified hydrazine-free carnosine were stored at 2 +/- 1degreesC for 20 days and evaluated for colour (a* and H*), TBARS, metmyoglobin formation (% of total surface myoglobin), psychrotrophic microbial counts and sensory odour. Results indicated that both forms of carnosine effectively inhibited lipid oxidation and color changes in beef patties throughout storage, showing no significant differences (P>0.05) between them. It was concluded that the antioxidant effect was brought about by the carnosine molecule and not by hydrazine. (C) 2002 Elsevier Science Ltd. All rights reserved.