Lettuce, like most leafy greens, presents a special food safety challenge.
Why? Because we eat it raw, and we place nearly all of our trust in what everyone else does before we purchase the lettuce–what they do on the farm, when harvesting, packaging, transporting, and storing the lettuce.
Unfortunately, we usually only learn what goes wrong when outbreaks occur.
Early days of produce food safety
It all started with raspberries in the 1990s, when more than 100 Floridians, including persons dining at posh Palm Beach restaurants, were infected by a parasite called Cyclospora. For most of the unlucky diners, it meant a protracted battle with diarrhea. But for some, those suffering immuno-compromising disease such as AIDS, it could mean death.
But who was the culprit? — Workers in Guatemalan raspberry fields, without adequate access to toilets and hand-washing facilities.
Here’s one scenario–a mother is picking raspberries with a child on her back. She needs to use the bathroom or the baby needs its cloth diaper changed. But there are no hand-washing stations in the field. As a result, her hands become contaminated with Cyclospora, which then contaminate the raspberries she’s picking.
Didn’t the raspberry company wash the raspberries, you ask? No, because raspberries are very delicate and washing shortens their shelf-life to such an extent that they would have spoiled before making the long trip to the USA.
Produce food safety today
We learned a lot from those outbreaks and from the unfortunate persons who suffered from Cyclospora. New regulations were implemented that now do not allow babies to be in the fields and that hand-washing stations must be located in convenient places for all workers.
Yet as we know, food safety problems continued after Cyclospora, especially those linked to leafy greens (like lettuce) contaminated with E. coli, Salmonella, and Listeria–three leading pathogenic bacteria.
In response, food companies have implemented even more safety measures before lettuce goes into a package–1) testing irrigation water, 2) not picking any lettuce within close proximity to a bird dropping in the field, and 3) dipping some types of produce in sanitizers.
But even with all of these protective measures, people still become ill.
Let’s say we own a lettuce farm and we test 1 gallon of irrigation water for Salmonella. The results come back negative (no Salmonella detected). Are we 100% assured there is no Salmonella in the thousands of gallons that we use to irrigate our lettuce field? NO. Our level of trust will be less than 100% because we only tested a small portion of the irrigation water. For example, if Salmonella was present in the water at 1 Salmonella cell per 100 gallons, then we would not detect it if we tested just 1 gallon. “Just test more water!” you might say. However, are you be willing to pay $20 or more for a head of lettuce, to support the cost of extensive testing? Probably not. Instead, we can have greater assurance about lettuce safety if we implement a whole series of food safety practices, such as using irrigation water that comes from a safe source, routine handwashing, and keeping animals out of the fields.
In Part 2, I discuss what we can do at the food store to enhance lettuce food safety.
If you wish, please share your comments about this blog.
Foodsafety.org is an online platform for disseminating and discussing food safety topics. All reasonable efforts are made to ensure that the information provided is free of errors and up-to-date but gives no guarantees as to the accuracy and completeness of that information or its fitness for any purpose whatsoever.
Foodsafety.org provides information and advice ‘as is’, without any conditions, warranties or other terms of any kind. Accordingly, to the maximum extent permitted by law, we provide you with content on the basis that we exclude any and all representations, warranties conditions, and other terms which but for this legal notice might have effect in relation with the website.
Foodsafety.org visitors must independently validate any and all food safety information before using such information to inform food handing, storage, and food preparation practices in their homes and/or businesses. For the most appropriate and safe application of Foodsafety.org information, expert interpretation is required. Users bear the responsibility to determine if they have such appropriate expertise.
Foodsafety.org may make changes to the material at any time without notice. Information may be out-of-date and we make no commitment to update it.
As with nearly all services offered on the internet, this website leverages a number of layers of third-party code libraries, some of which may work as expected one day and not the next, due to the fact that third-party software will be updated over time (and beyond our control), and some third-party software may not be supported by your particular device or browser, or the specific version of your particular browser. Furthermore, all computer code is subject to the risk of errors.
The Terms and Conditions set out herein apply to the use of Foodsafety.org information. By accessing Foodsafety.org, you agree that you have read and accept these terms and conditions. If you do not agree to these Terms and Conditions, do not use Foodsafety.org.
Foodsafety.org is a trade name and division of BioSecure Risk Management, Inc. “(BioSecure”) BioSecure, its officers, directors, employees, shareholders or agents (the “Company”) accept no liability for any loss or damage arising from any inability to use Foodsafety.org.
The Company excludes all liability and responsibility for any amount or kind of loss and damage that may result to you or a third party (including without limitation, any direct, indirect, punitive or consequential loss or damages), or loss of income, profits, goodwill, time, data, contracts, use of money, or loss or damages from or connected in any way to business interruption, and whether in tort (including, without limitation, negligence), contract or otherwise in connection with Foodsafety.org in any way or in connection with the use, inability to use the results of use of Foodsafety.org, any web site linked to Foodsafety.org or the material of such web sites, including but not limited to loss or damage due to viruses that may infect your computer equipment, software, data or other property on account of your use of Foodsafety.org or your downloading of any material from Foodsafety.org or any web site linked to Foodsafety.org.
The Company is not responsible for the availability, content or security of any other websites accessed through the website and accepts no liability for, and gives no endorsement of, material on or other services provided through such web sites. Foodsafety.org recommends that you check the terms and conditions and any policies of such sites and contact the owner or operator if you have any concerns. Any use of such material or services is at your own risk.
Under no circumstances will consent be granted to create a deep-link to the Foodsafety.org.