Antioxidant effect of carnosine and carnitine in fresh beef steaks stored under modified atmosphere

The exogenous aplication of carnosine (β-alanine-L-histidine) (50 mM), carnitine (50 mM) and L-ascorbic acid (500 ppm) solutions on the shelf life of fresh beef steaks packaged in modified atmosphere (70% O2+20% CO2+10% N2) was studied. Beef steaks were sprayed with natural antioxidant solutions at a ratio of 2 ml solution to 100 g meat. Lipid oxidation (TBARS formation), colour changes (CIE a* value and metmyoglobin formation), antimicrobial properties (psychrotrophic flora), and sensory (off odour and discolouration) changes were examined throughout 28 days of storage. Results showed that the combination of carnosine with ascorbic acid provided the best antioxidative protection with regard to meat deterioration. Surface aplication of carnosine or ascorbic acid alone resulted in an effective delay of oxidation of meat. However, carnitine was significantly (P<0.05) less effective than any other antioxidant in delaying meat oxidation, while the combination of carnitine and ascorbic acid exerted no antioxidant effect.