Abstract: Samples of fresh beef muscles(Longissimus dorsi) were packed under varying modified atmosphere conditions (O2、20～80%、CO2 20～60%、N2 0～20%)and stored at 3±1℃ for 12 days. At 2 day intervals meat samples were analysedfor colony forming unit, Ecoli most probable number, pH, content of metMb,lipid oxidation(TBARS), total volatile basicnitrogen and sensory evaluation.The results infered that the modified atmosphere at level of 60% O2 and 20% CO2 and 20% N2is the best one for chilling beef.

Key words: chilling beef, modified atmosphere packaging(MAP)