Incidence of mesophilic anaerobic bacteria and lactic acid bacteria on sliced bread under modified atmosphere packaging during storage

A total of 192 samples of sliced bread of different composition, water cont ent and pH were selected to test the efficiency of modified atmospheres pac king (MAP) on total mesophilic anaerobic bacteria and lactic acid bacteria (LAB) counts during MAB storage. The addition of calcium propionate and the storage temperature influenced significantly the counts. During most of th e storage period at 15-20C, the concentration of O-2 was very low and that of CO2 was constant or increased according to the atmosphere used. LAB coun ts increased in a significant way in the first week under CO2 atmospheres. For the sliced bread, the highest counts were obtained under CO2 atmosphere s. In general, we consider that the presence/absence of calcium propionate added had a greater influence than the MAP conditions.