THE MICROBIOLOGY OF MINIMALLY PROCESSED FRESH FRUITS AND VEGETABLES

Minimally processed fresh (MPF) fruits and vegetables are good media f or growth of microorganisms. They have been involved in outbreaks beca use of the consumption of products contaminated by pathogens. They are also sensitive to various spoilage microorganisms such as pectinolyti c bacteria, saprophytic Gram-negative bacteria, lactic acid bacteria, and yeasts. Contamination of MPF fruits and vegetables occurs at every stage of the food chain, from cultivation to processing. Polluted env ironments during cultivation or poor hygienic conditions in processing increase the risk of contamination with foodborne pathogens. Although MPF fruits and vegetables may harbor psychrotrophic microorganisms su ch as fluorescent pseudomonads or Listeria monocytogenes, good control of refrigeration temperature limits growth of spoilage and pathogenic microorganisms. Modified atmospheres are often efficient to maintain or improve visual and organoleptic quality of MPF fruits and vegetable s, but their effects on microorganisms are inconsistent. Chemical disi nfection can partially reduce the initial bacterial contamination; irr adiation seems to be more efficient. The applications of legislations and quality assurance systems to control contamination, survival. and growth of foodborne pathogens in MPF fruits and vegetables are discuss ed.