Robert Blenkinsop, Food Scientist - Ontario Ministry of Agriculture and Food
Microbial contamination can be introduced onto fresh produce during production, harvesting, packing or processing by equipment, people and water. An integrated preventative approach that includes Good Agricultural and Good Manufacturing Practices will help reduce initial microbial loads on fresh produce.
Narrator
Regardless of the type of produce, the initial microbial load or the type of washing system used, managing the microbial quality of wash water is essential to minimize the potential transfer of pathogens and spoilage microorganisms from the wash water to produce. Whether the water is used for washing, cooling or transporting product, minimizing this cross-contamination risk is an essential step in managing the food safety and quality of fresh and fresh-cut produce.
Pride Pak Canada processes fresh-cut vegetables and, vegetable mixes, at their Mississauga location for Canadian and U.S. markets.
Angelo Karr, VP Pride Pak Canada
Washing is important to our products by removing bacteria load which will increase shelf life and quality of the product.
Narrator
Washing whole and fresh cut produce removes soils and debris, pesticide residues and microorganisms from product surfaces. Reducing microbial levels on the product has important implications for product safety, quality and shelf-life.
Angelo Karr
Our wash water is being re-circulated; therefore we need a sanitizer to maintain the microbial quality in the water.
Narrator
Re-circulated wash water may contain pathogenic or spoilage microorganisms that can create a cross-contamination risk for incoming product being washed in the same water.
Angelo Karr
You want to ensure that the wash water sanitizer treatment is optimized and that the microbial quality of the wash water is being monitored and maintained.
Narrator
Sanitizer concentrations must be maintained at levels that are effective at killing microorganisms present in the wash water without adversely affecting the quality of the produce being washed.
Angelo Karr
What our staff would do here to monitor is we have a ORP pulse system that's constantly testing the water and adding as needed.
Narrator
Oxidation Reduction Potential or ORP is a commonly used means of monitoring the effective sanitizer concentration. That is, the level of active sanitizer present in the water for killing microorganisms. Manual or automatic ORP systems may be used to monitor and control sanitizer levels in the wash water.
Angelo Karr
Wash water is constantly being charged with fresh water to keep our microbial loads down.
Narrator
Continually adding an amount of fresh, clean water to the wash tank is one way of slowing the accumulation of microorganisms in the wash water.
Martin's Family Fruit Farm, located in Waterloo, grows and packs fresh apples for domestic and export markets.
Steve Waring, Martin's Family Fruit Farm
Washing is important for apples because of the microorganisms that may come in from the field. It's important because we need to be able to ensure the quality of the apples.
Washing also reduces spoilage and preserves the quality of the apples.
Narrator
Production staff verifies the microbial quality of the wash water using a hand-held ORP meter. This reading is an indication of the ‘disinfection potential' of the wash water. This measurement assists staff in determining whether the sanitizer concentration is at the correct level or whether more sanitizer needs to be added to the wash tank.
Steve Waring
Our wash water is being recirculated in wash tanks; therefore it is necessary to add a sanitizer treatment to wash water to limit microbial growth in the wash tank. The sanitizer that we us in our plant is sodium hypochlorite. We want to ensure that product is free-flowing in the wash line, which means designing the process so that product is being exposed to the sanitizer-treated water to allow immersion and sufficient contact with the sanitizer-treated water.
Agitation of the product in the wash water is also an important consideration. We must perform periodic monitoring of sanitizer concentration pH to ensure that the wash water / sanitizer treatment is optimized and that the microbial quality of the wash water is being maintained. We also have a fresh water rinse that removes the residue of the sanitizer from the apples.
Narrator
While the type of the produce, the style of the washing system and the type of sanitizer may differ, managing the microbial load of wash water is essential to minimizing the risk of microbial cross-contamination of fresh and fresh-cut produce. Proper wash water management will result in increased product safety, quality and shelf-life.
For more information, please visit:
http://www.ontario.ca/producesafety

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