Freshly picked apples from the orchard are smooth and shiny – does that make them “clean”?
According to Carol Allen, University of Maryland Plant Science, it’s easy to think apples are clean based on appearance, but there are plenty of opportunities for them to become contaminated before reaching the consumer.
“There are foodborne illness outbreaks that come from apples,” said Allen. “One of the places we get cross contamination is from workers, and from baskets and other tools used in apple picking. Apples are popular for eating raw, and when there’s an apple in someone’s hand, there’s potential for foodborne illness contamination.”
Allen believes good initial worker training and ongoing training are key in preventing contamination. The challenge is cleaning and sanitizing the many surfaces involved with apples.
“We have a greater chance of cross contamination with food contact surfaces,” said Allen. “The tradition is beautiful old wooden bins, but we know by their nature they have surfaces that defy adequate cleaning and sanitizing. Apple picking baskets are another big challenge because they have soft surfaces including leather and canvas.”
The target is removing biofilms, which are colonies of bacteria coated with long-chain sugars that protect the colonies from environmental stressors. Biofilm is difficult to remove from food contact surfaces, but it’s possible with water, detergent and scrubbing.
The first cleaning step is eliminating visible dirt – sweep it off, rinse it, remove it. Next, use a dedicated scrub brush and detergent to scrub to remove invisible dirt. Any food-safe detergent, such as that used for dish washing, is suitable.
The third step is to rinse until the item is visually clean. Then apply sanitizer according to label instructions, ensuring the correct contact time is allowed.
“The sanitizer must dry before it’s ready for use,” said Allen. “Next, record what you’ve done.” While recording is an easy step to delay or even skip, Allen said it’s the farmers’ insurance policy.
“Worst case scenario – foodborne illness is traced back to your operation,” said Allen. “Agents are all over, taking samples of everything. Your ‘insurance policy’ is to bring out records and show what you did.”
Records can be as simple as writing on paper or as technical as using a QR code to access an online document where workers record cleaning and sanitizing procedures. Codes can trace back to SOPs that outline exactly how the process was completed.
Selecting sanitizers can be challenging. The Produce Safety Alliance has a spreadsheet that provides a comprehensive list of EPA-labeled sanitizers suitable for produce handling areas. The spreadsheet includes trade names, active ingredients of products, labeling specifics, OMRI status and other information.
Allen suggested growers prioritize primary zones in the packing house. Zone 1 is the sorting table; Zone 2 is adjacent to Zone 1 and includes the edge of the table and table legs. Contaminants can be easily moved from Zone 1 to Zone 2. Zone 3 includes floors, walls and ceiling. Allen reminded growers to maintain records for cleaning each zone.
“Analyze the packing area, look at the zones and look for potential cross-contamination,” she said. “Prioritize the surfaces depending on their use. You might clean the ceiling just once a year.” Because each operation is unique, the farmer determines cleaning intervals.
Bulk bins are difficult to clean due to their size and texture. When possible, growers who use wooden bins should consider phasing them out in favor of plastic bins. “The wood harbors pathogens, but after a while, plastic becomes worn and the texture increases,” she said. “Part of worker training is informing workers to watch for [plastic] bins that become rough.”
Wooden crates are ubiquitous when it comes to apple harvest, but they can be havens for bacteria that cause foodborne illness.
The most important factor in keeping harvest equipment clean is workers. Allen noted, “They’re frequently the last people to touch produce before it goes to the consumer.”
Worker training should focus on reducing risk. Teach proper hand washing and be sure employees know how to recognize and report illness and injuries. “Most workers are hourly, so if they call and say they are sick, they aren’t making wage that day,” said Allen. “As an owner/operator, how are you going to gain trust to make sure your workers can afford to work for you?”
Workers should be aware of the cleaning and sanitizing schedule and understand the SOPs for each procedure. Clean clothing each day should be standard, along with safe and washable footwear. Teach workers how to recognize when equipment is worn and how often to clean and sanitize equipment.
Visitors should be aware of the production facility’s policies. If someone comes into fix a compressor and puts a toolbox on the grader belt, the grader is contaminated. “How are you going to communicate that you have rules and regulations in your packing house?” she said. “You don’t want inadvertent cross-contamination.”
Repeat training is important to instill basic practices. “Follow the same rules you expect employees to follow,” said Allen. “If you come to the harvest line with yesterday’s clothing you wore while harvesting potatoes, that’s a no. The goal of training is to build a culture of food safety. You need full buy-in from everyone.”
Establish SOPs and make them readily available to employees. Communicate orally and have written expectations on signage, in the employee handbook and in the farm’s food safety plan. Will you require beard nets and hair nets? Is jewelry allowed? Are gloves required, and if so, what kind and who purchases them? Make sure that workers know if they use the restroom, any outerwear (apron, gloves, hair net) should be removed prior to entering the restroom. Provide a clean area for such outerwear.
There should be written procedure for everything possible, from sick employees to handling a toilet overflow. If someone must be corrected more than once, be prepared to retrain, and if a worker has ongoing difficulty with a task, move them to another area of the farm.
Make sure there are adequate first aid kits that are properly stocked and updated as needed. “Have a policy for cleaning wounds and separating bodily fluids from the task,” said Allen. “Contaminated items or areas, including the floor, should be cleaned and sanitized.”
Field porta-potties should be at least three feet from the growing area. Hand washing stations should have soap, water, disposable towels and a disposal receptacle. Hand sanitizer is not an appropriate substitute for hand washing.
“Clean” begins at home. “If the last thing you do before driving to work is petting Fido on the head, you’ve got dirty hands,” said Allen. “After touching animals or animal waste, hands should be washed.”
Access details about cleaning from the Produce Safety Alliance at cals.cornell.edu/produce-safety-alliance.
by Sally Colby
