pH values decreased during storage time for all storage conditions (Fig. 1). Initial pH values dropped slowly in air packed samples the first 8 days, but at a faster rate on further storage when lactic acid bacteria reached their maximal counts (Fig. 6). The highest decrease rates were found in vacuum and modified atmosphere packed samples, which is in accordance with their highest counts of lactic acid bacteria. Meat pH can be affected by many factors; however, growth of lactic acid bacteria resulting in lactic acid production is the major factor in pH decrease in packaged meats (Gill, 1996). At day 18 of storage, pH differences (P < 0.05) were found between meat air packed and the others, but not between vacuum, MAP and MAP + CO packed ones.