Some of the most famous super-villains of all time were best known for their signature green color, from the Wicked Witch of the West to the Green Goblin to Frankenstein’s monster. What you probably haven’t realized is that the biggest threat of them all has been hiding right in your salad bowl for years. From iceberg lettuce to escarole, leafy greens are quickly becoming a serious food safety concern across the nation. Lately, greens have been making the news more often, not for their astounding health benefits and caloric value, but for a far graver reason. These nutritional powerhouses are being linked to outbreaks of E. coli, Listeria, and Salmonella, as well as noroviruses, which can lead to stomach-flu-like illnesses.
The Fault In Our Greens
The main problem stems from the leafy greens’ natural richness in nutrients. Once cut, the greens pump nutrients out of the open lacerations, feeding bacteria and providing a pathway for microbiological intruders to reach the plant’s inner tissues. With the pathogens inside the greens, rather than simply residing on the outer leaves, it becomes much more difficult to remove or kill the bacteria, creating a greater potential for contamination.1
An example of such threat can be found in the history of raw sprouts. Sprouts grow best in warm, wet environments that allow the seed inside them to germinate. Coincidentally, these conditions are also the environment in which pathogens and bacteria grow best. Because the bacteria will grow with the sprouts, there is virtually no way to guarantee that the contaminants will be completely eliminated unless the sprouts are cooked.2 The combination of optimal growing conditions and unreliable pathogen removal methods has led to multiple incidents sometimes even resulting in hospitalization. Since 1998 there have been over 40 food-borne illness outbreaks, as well as 1,737 sprout related sicknesses.3 Even more recently, some chain restaurants, most notably the popular sandwich shop Jimmy John’s, have been traced to outbreaks of E. coli caused by contaminants in the sprouts they served.4
Definitions and Rules and Regulations — Oh My!
It can be difficult to determine exactly what a cut leafy green is, or which practices you should be paying attention to in order to avoid contaminating your produce. For the most part, it seems that a cut leafy green is any plant that qualifies as a leafy green and has also been cut, chopped, shredded, sliced, or torn in some way that is not a part of the harvesting process.
“Leafy greens that have only been cut from their root in the field (a harvest cut) with no additional cutting, shredding, slicing, chopping, or tearing are not cut leafy greens. Leafy greens that simply have the stem, stalk, butt, or core trimmed are not cut leafy greens. This would apply to heads of lettuce and cabbages or whole clumps of leaf lettuce or spinach. In all cases, the exterior leaves may be discarded. If the core of a head of lettuce or cabbage is completely removed then the remaining leaves are cut leafy greens. But the entire plant harvested from the field would not be a cut leafy green.”
– Joe Graham, food safety official, WA Health Department 5
When dealing with cut leafy greens, preventive action, rather than reaction, is essential. One of the simplest and most effective ways to control the growth of bacteria, be it in or on food, is through temperature. In cases such as these, colder is safer, as it keeps any bacteria from multiplying when the food is not being treated. In fact, the FDA’s 2009 Food Code requires that any potentially hazardous foods be kept at 41o Fahrenheit from the point of harvest to the final point of sale.5
Other practices that can help you contain any increases in bacteria or pathogen population include extensive and rigorous testing of the soil and any soil amendments that may have been made, the water used for irrigation, and assessments of the environment, pre-season and post-harvest.6 The 2011 FSMA Act established the minimum standards for each of these parameters, as well as regulations pertaining to the proper use and sanitization of equipment, tools, and facilities.7 In addition, you and your employees should be upholding general good food safety practices when dealing with leafy greens, particularly by following a complete food safety compliance plan, having an up-to-date list of growers on record, and keeping a written trace back plan in the event of a recall.8
With scrupulous testing and documentation that results in preventive action, the chances of pathogens attaching themselves to your produce are considerably minimized. By maintaining Good Agricultural Practices (GAPs) in the field and Good Manufacturing Practices (GMPs) in your facility, the threat will be lessened even further.
If you’d like more details on how to avoid potential outbreaks, download the FDA’s Compliance with and Recommendations for the Growing, Harvesting, Packaging, and Holding of Produce for Sprout Operations.
What You Should Be Doing to Reduce the Threat
Aside from keeping up with your GAPs and GMPs, there are a few simple steps you can take that will be monumental in the battle against contamination in your facility.
When Handling Food
As discussed, leafy greens can be temperamental, and should be handled properly to avoid contamination. We’ve listed some basic rules of thumb that will help you keep your product pathogen-free.
- Greens should not sit without refrigeration for more than two hours, particularly if they have been cut.
- Greens should be housed and processed in areas separate from raw foods like meat, poultry, and seafood.
- If any of your produce has made contact with juices from raw foods, it must be thrown away.
- Completely sanitize or use different equipment and preparation areas before proceeding with the processing of greens.9
- Any sprouts that are damaged, have nonwhite stems, a slimy appearance, or a musty smell should be discarded.10
- Any greens that may have been compromised in some other way must be discarded.
- Employees that handle the produce must wear gloves and wash hands and supplies before and after working with the product.11
Around the Facility
One of the best ways to ensure that your facility is up to code is to conduct government audits on a regular basis. This practice will provide you with invaluable feedback and instruction on the places in which your facility can improve and where you are performing well. Along with government testing, you should maintain a system of self-inspection as well, monitoring things such as water quality and the status of any soil amendments.
An important factor to consider is the regulatory policies of your seed supplier. Many of the primary sources of contamination begin with the seeds, so check with your suppliers to ensure they are doing all they can to reduce those risks. Threats that should be focused on include:
- Birds flying over the field
- Deer, rabbits, raccoons, field mice, rats, and feral hogs in the field
- Farm workers who have neglected to wash their hands and/or put on gloves
- Unfiltered water that could contain runoff from livestock pastures or host pathogens
- Certain fertilizers12
In addition to field bound concerns, firm-level issues can also be a gateway to contamination. Keep your facility free of virulent microbes by remembering these simple food safety guidelines.
Have a complete food safety plan to follow, as well as a list of growers and a written trace-back plan that you can reference when needed.
Make regular assessments of the environment so as to be sure that any factors that may affect food safety are controlled or removed. This includes a facility’s proximity to animal feeding operations, as well as the potential for animal intrusions and flooding.13
Test your produce and follow the FDA recommended test and release procedures. If a test returns a pathogen positive result, you may either:
Discard all the product from that production lot and sanitize all equipment
Conduct a confirmatory test using a qualified laboratory and hold the affected produce until the test results come back. If the results are negative, the product may be shipped. If the results are positive, you cannot ship the product for consumer consumption.
Have sufficient procedures to evaluate, screen, and test incoming seed lots thoroughly before use or processing. Click here to read a letter from the chief of the Food Safety Inspection Unit that contains a detailed list of the procedures you should have in place.14
Test and keep records on all sources of water used in the production of leafy greens and the cleaning of equipment
When cleaning product, microbes must be removed along with dirt and foreign matter without severely damaging said product.15
Extensive testing, certification, and record keeping for soil amendments, including compost and fertilizers must be kept.
Conduct field audits to confirm that farmers are in compliance with areas of worker practices and field sanitation.
Keep produce chilled while it is being transported.
All this may seem rather overwhelming at first, but it is crucial that these practices and procedures are observed as you endeavor to prevent outbreaks and food-borne illnesses. By remembering and upholding these guidelines, you will be able to protect your consumers and your produce.
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