The shelf-life of beef steaks treated with DL-lactic acid and antioxidants and stored under modified atmospheres

Beef steaks were treated with 1.5% lactic acid alone or supplemented with antioxidants (0.1% rosemary extract and 0.05% ascorbic acid). The steaks were stored under modified atmospheres containing either 60% O-2/40% CO2 or 70% O-2/20% CO2/10% N-2. Both the 40% CO2 atmosphere and the lactic acid treatment significantly (P<0.05) inhibited growth of lactic acid bacteria, Brochothrix thermosphacta and Pseudomonas spp. Neither CO2 in the pack atmosphere, treatment with lactic acid, nor a combination of both, affected formation of thiobarbituric acid reactive substances, myoglobin oxidation, or CIE a* values. However, treatment with antioxidants significantly (P < 0.05) delayed oxidation of both myoglobin and lipids, and so extended the storage-life. (C) 2002 Elsevier Science Ltd. All rights reserved.