ABSTRACT
The demand by consumers for fresh and fresh-cut fruits and vegetables has
steadily increased due to nutritious qualities associated with fresh produce
and the convenience of ready-to-eat fresh foods. This increased demand has
resulted in increased per capita consumption of fresh produce. Although
fresh produce is generally considered safe, it has been implicated in numerous foodborne outbreaks in recent years. The Centers for Disease Control and Prevention reported that foodborne outbreaks associated with fresh produce doubled between the period 1973 to 1987 and 1988 to 1992 [1]. Contamination of fresh produce, often grown on the ground and/or in areas adjacent to animal production, with human pathogens may occur during growth, harvesting, handling, and processing. Conventional washing and sanitizing treatments have limited efficacy in inactivating and/or removing pathogens on the surface of produce. Survival of human pathogens and other bacteria during washing and sanitizing treatments is attributed to their attachment to inaccessible sites on produce surfaces such as within the netting of a cantaloupe [2], infiltration within the stem scar of tomatoes and the calyx region of apples [3,4], and incorporation into biofilms, as seen with apples [3], cantaloupes [2], and leaf surfaces [5,6]. Inadequate decontamination of fresh produce can result in the survival of human pathogens on the surface with the possibility of subsequent transfer of the pathogen from the surface, such as the rind of a cantaloupe or the peel of an orange, to the flesh during fresh-cut processing or juice extraction, respectively. Thus, the safety of fresh and fresh-cut produce in supermarkets and salad bars, as well as the safety of freshly squeezed unpasteurized juices, especially those served in fresh juice bars, is of concern. Although experimental approaches to washing produce, such as vacuum infiltration of sanitizers and application of abrasives during washing, have resulted in greater microbial reductions compared to conventional treatments [7], these new treatments are not capable of adequately inactivating the pathogenic bacteria in their protective attachment states on produce surfaces. Furthermore, inactivation of sanitizing agents by organic material such as soil and debris in the washing solution, prior to contact with microorganisms, may limit their sanitizing effectiveness [8].
