Postharvest Quality and Safety in Fresh-Cut Vegetables and Fruits

NON-TECHNICAL SUMMARY: Consumption of fresh-cut produce has increased significantly based on its well-known health benefit and convenience to consumers. The International Fresh-cut Produce Association estimates that fresh-cut products currently make up more than 15% of all fresh produce marketed in the U.S. Unfortunately, as produce consumption has increased in the U.S. in recent years, so has the number of produce-related outbreaks of foodborne illness. Produce-related outbreaks accounted for 6% of all reported foodborne outbreaks in the 1990s compared to only 0.7% in the 1970s according to FDA. The conditions on the cut surface of fresh-cut products, with the presence of water and compounds that microbes can use for nutrition, provide ideal conditions for growth, however, it is difficult to compare the results of studies on survival and growth of pathogens done in different laboratories because substantial variations exist in methods for inoculation, treatment, or storage, and in procedures used to detect, recover, or enumerate pathogens on raw produce. The continuing nature of such produce-related outbreaks represents a threat to further increases in per capita consumption due to lowered confidence in the microbial safety of the product by the consuming public. Such outbreaks can also be very costly to growers, processors, shippers and restaurants. The long-term goal of this project is to enhance microbial safety and quality of fresh-cut fruits and vegetables through developing integrated methods to quantify quality of fresh-cut produce and novel pre- and postharvest treatments to ensure product quality and safety. Integrated physiological, pathological, food safety, and instrumental and sensory quality measurement will be used for developing the most effective handling procedures and innovative, new technologies for maintaining quality and shelf stability of fresh-cut produce. Experiments will be conducted to optimize and integrate new and emerging treatments in diverse fresh-cut produce. Alternative and emerging technologies for maintaining the quality and shelf stability of fresh-cut produce will be continuously studies, including surface disinfection treatments using zone and electrolyzed water, edible coating, vacuum impregnation and MAP. Treatment impact on product nutritional value, microbial quality and food safety will be evaluated. <P> APPROACH: Objective 1: Compare techniques for product profiling and difference testing and relate instrumental with sensory measurements by using newly developed instruments and statistical techniques. PI will participate in the review of the quality rating scales and work on quality evaluation comparing sensory data with physicochemical analysis with novel instrumentation. <P>Objective 2: Evaluate edible coating, vacuum impregnation, MAP and new/emerging MAP-alternatives and the means to integrate these studies into a hurdle strategy to maintain the appearance, texture, and nutritional quality of fresh-cut produce. Treatments will be evaluated for their ability to maintain microbial quality and food safety. Proposed treatments may be done before and/or after fresh-cut processing. Fresh-cut apples, pears and other fruits will receive the most emphasis, but fresh-cut vegetable products will also be tested. The effects of various pre- and post-cutting treatments on fresh-cut fruit and vegetable quality attributes will be investigated. <P>Objective 5: A variety of intervention technologies will be tested alone and in combination on ensuring microbial safety of fresh-cut produce. Common microbiological methods will be used for enumeration of native microbes and pathogens that survive the intervention treatments. Appropriate controls will be included in each experiment and experiments will be replicated at least two times. A number of natural products with broad-spectrum antimicrobial activities, newer sanitizers such as ozone, electrolyzed water and organic acids, edible coatings with or without food additives and preservatives, novel microbial antagonists, and non-chemical treatments such as short-term, minimal exposure to high hydrostatic pressure will be tested for antimicrobial effects in conjunction with Objective 2 activities with interaction between the physiologists and microbiologists.