Microbiology of minimally processed, modified-atmosphere packaged chicory endive

Modified-atmosphere packaging (MAP) and subsequent storage at refrigeration temperature has been developed over the last decade as an adequate technique to prolong high quality shelf-life of minimally processed vegetables. The MAP system employed should be carefully tailored to the physiological and microbiological characteristics of the product in order to achieve good quality, safe products, In the current investigation, controlled atmosphere conditions were employed that mimicked the packaging of fresh cut chicory endive under modified atmospheres in order to establish the microbiological characteristics. It was found that the modified-atmosphere conditions that were favourable for product quality, retarded growth of spoilage micro-organisms during storage at low temperature. Growth of the psychrotrophic pathogen Listeria monocytogenes, inoculated on the product, was not inhibited. The extent to which the pathogen grew depended on its initial number, type of chicory endive and size of the population of competitive spoilage microflora. Reducing the initial microbial load by disinfection could minimize microbial spoilage and improve the safety status of the product. However, L. monocytogenes grew better on disinfected produce than on non-disinfected or water-rinsed produce, indicating the practical importance of avoiding recontamination after disinfection.