EFSA experts have investigated the quality of water used during operations in the fresh and frozen produce sector.
The European Food Safety Authority (EFSA) has asked the Biological Hazards Panel (BIOHAZ) for a scientific opinion on the microbiological hazards associated with the use of water in the processing and post-harvest processing of fresh and frozen fruit, vegetables and herbs.
The use of water during collection and processing is a significant risk factor for contamination of such products. Relevant microbial hazards include Listeria monocytogenes, Salmonella, E. coli, and viruses such as norovirus.
Large volumes of water are used for washing, rinsing, flushing, cooling, cooling, general cleaning, sanitation and disinfection. For example, large amounts of water are needed to produce packaged salads. Most post-harvest processors prefer to use the same water during many hours of operation to conserve water and energy, as access to potable water may be limited or expensive.
Based on current practices, potable water is used to fill equipment and tanks in the first hour of the morning and is not replaced for several hours or even days in some cases, during which time large quantities of fruit, vegetables and herbs can be processed. according to the report.
Contamination of process water is affected by several factors, including the type of produce being processed, the duration of the operation, and the transfer of microorganisms from the product to the water and vice versa.
To avoid cross-contamination of the product due to the use of contaminated water, water disinfection procedures are necessary to eliminate or reduce microorganisms to an acceptable level, but they should not harm the quality and safety of the produce.
The effectiveness of disinfection treatments depends on the specific treatment conditions, including the initial water quality and the type of treatment.
Chlorine-based disinfectants and peroxyacetic acid are common water disinfection treatments. Validation, operational monitoring and verification are required to demonstrate effectiveness. Hygienic practices include infrastructure maintenance, staff training, and post-harvest cooling of process water.
The experts’ efforts included literature review, outbreak surveillance data, and industry research.
Water control based solely on a Prerequisite Program (PRP) is no longer feasible and a HACCP-based approach is required for water management. Good Manufacturing Practices (GMP) and Good Hygienic Practices (GHP) associated with a water management plan and implementation of a water management system are critical.
Based on industry survey responses, three best practices are still not well implemented: replacing infrastructure to avoid biofilm formation, looking for biofilm formation in the water management system, and water cooling. The responses indicate that process water quality monitoring is absent or weak.
In some outbreaks of listeriosis, investigations have determined that contamination occurred at the processing plant; however, bacteria can also enter the factory from primary production. Despite outbreak investigations, the route of infection is rarely confirmed.
Emerging farming practices such as hydroponics, vertical farming and urban farming can introduce pathogens into the food chain, although the rate of this is expected to be lower than conventional farming, according to the report.
The BIOHAZ panel recommended that more information be included in outbreak investigation reports and that clear guidance be made available to companies to clarify requirements for how water disinfection treatments can be used to maintain the microbiological quality of treatment water and post-harvest processing of fruits, vegetables and herbs.
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