Relation between spoilage and microbiological quality in minimally processed artichoke packaged with different films Original Research Article

The atmosphere surrounding minimally processed vegetables is extremely important to extend their shelf-life, and one of the most influential factors on its composition is the permeability of the film used in the packaging. This study determined the impact of the preservation technologies on sensory quality (weight losses, color, texture and sensory acceptability) and on the growth of indicator micro-organisms (mesophiles, psychrotrophs, anaerobic micro-organisms, sporeformers, faecal coliforms, Salmonella and Escherichia coli) in minimally processed artichoke packaged with five different films (two PVC and three P-Plus). The atmospheres obtained, together with the different permeability to water vapor of the films under study, determined the evolution of the visual and microbiological quality of the artichoke. For most of the batches, no correspondence was found between microbial growth and changes in appearance. Those batches where the equilibrium atmosphere was clearly anaerobic showed microbial counts below the legally established microbiological limits but also showed a rapid loss of sensory quality. On the other hand, some batches with an acceptable sensory evaluation had microbial counts higher than those allowed by the legislation. This last situation is particularly dangerous from a health point of view since it allows the growth of micro-organisms (even pathogens) although the product may seem to be acceptable for consumption. This lack of correspondence constitutes an important point to be attended to on the microbiological safety of these foods, since the preservation technologies applied allow the prolonging of their sensory characteristics but, at the same time, may favor the growth of micro-organisms.