The Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have released a comprehensive report focused on mitigating microbiological risks in fresh fruits and vegetables. This analysis, part of the Microbiological Risk Assessment (MRA) series, delves into various categories of produce, including leafy vegetables and herbs, berries, tropical fruits, melons, tree fruits, and seeded and root vegetables.
The report originates from the Joint FAO/WHO Expert Meetings on Microbial Risk Assessment (JEMRA). While a summary of findings was released last year, this final report provides a detailed examination of the subject.
In 2019, the Codex Alimentarius Commission approved guidelines for controlling Shiga toxin-producing E. coli (STEC) in leafy vegetables and sprouts. JEMRA responded by conducting sessions addressing the prevention and control of microbiological hazards in fresh fruits and vegetables. These discussions considered ready-to-eat and minimally processed produce, including leafy greens, as well as sprouts produced from seeding to point-of-sale.
The report explores strategies for reducing risk at various stages of production, from primary cultivation through post-harvest, transportation, point of sale, and consumption. Given that these products are typically consumed raw and have limited shelf life, implementing preventive measures such as good agricultural practices (GAPs) and good hygiene practices (GHPs) during primary production was identified as the most effective means of pathogen risk reduction.
Post-harvest activities require GHPs, good manufacturing practices (GMPs), and a hazard analysis and critical control point (HACCP) system to prevent microbial contamination, reduce cross-contamination, and prevent pathogen growth.
The report highlights the diverse production systems used for growing various leafy vegetables in regions with differing environments, biodiversity, and climates. These crops are distributed to consumers through various market channels. Irrigation water, often of inconsistent microbiological quality, was identified as a significant risk factor in fruit and vegetable production. Additionally, the quality of process water was deemed crucial.
While several methods, such as UV, plasma, pulsed light, and ultrasound, have been studied for disinfecting process water, there is limited evidence of their use in the industry. Experts emphasized the need for further research to assess the practicality and performance of new technologies under conditions resembling real-world production and processing.
In the context of post-harvest treatments, irradiation emerged as the most effective method against pathogens on vegetables, but commercial adoption faces challenges due to cost and consumer response. Electrolyzed water, along with other treatments, showed potential for reducing bacterial pathogens. Bacteriophages were also considered, but both approaches had drawbacks.
The report examines specific approaches for different types of produce. For berries, which can be grown in open fields or controlled environment agriculture (CEA), water-assisted treatments like UV and pulsed light showed promise. Gas-based methods like controlled-release pads had variable effects. Tropical fruits, primarily grown on trees or bushes, benefited from similar treatments. Pome fruits, such as apples and pears, were subjected to controlled atmosphere and cold storage to extend their shelf life.
For melons and tree fruits, the main safety strategy involved hygienic handling, environmental monitoring during sorting and packing, and maintaining contamination-free packing environments and equipment.
However, the report also noted that much of the research conducted in these areas has focused on a limited number of bacterial foodborne pathogens, leaving gaps in knowledge concerning protozoan or viral targets.
This comprehensive report underscores the importance of managing microbiological risks in the production and handling of fresh fruits and vegetables, particularly as consumer demand for safer, healthier, and tastier food options continues to rise in the food industry.