Combined effects of Lactobacillus casei inoculum, modified atmosphere packaging and storage temperature in controlling Aeromonas hydrophila in ready-to-use vegetables

Carbon dioxide concentration, Lactobacillus casei inoculum size and storage temperature were varied according to a Central Composite Design in order to assess the effects of these variables and their interactions on the growth of Aeromonas hydrophila and lactic acid bacteria in ready-to-use mixed salad vegetables packaged under modified atmosphere. The growth curve parameters, modelled according to the Gompertz equation, were analysed to generate polynomial equations. The model obtained emphasized the role of L. casei inoculum size in controlling A. hydrophila and permitted identification of appropriate combinations of the selected variables to reduce A. hydrophila survival. The use of these hurdles may increase the shelf-life and the microbiological safety of ready-to-use vegetables.