It’s almost every week that we hear about folks getting sick from fruits and vegetables. Right now, in the DMV (DC, Maryland, Virginia) region there are some outbreaks of cyclosporiasis (via the cyclospora parasite). In the recent past, these outbreaks have been lined to raspberries, basil, arugula, mesclun, cilantro, and prepared salads.
Almost four decades ago, we worked with Kruger Farms to prepare the first non-heat pasteurized apple cider. Building on our research with water and wastewater treatment, we produced a large-scale ultraviolet (UV) light system for their production lines that killed the microbes in the fresh-squeezed cider, before it was bottled. (Even though plastic containers are used, we still call this process ‘bottling’.)
This allowed Kruger Farms to offer consumers a 120 day shelf life for its cider. That was about 8 times the longest life conventional apple cider had- unless one froze it. (That kind of kills the idea of having ‘fresh’ apple cider’.) Moreover, this means Kruger Farms could expand to national distribution.
Now, Paul Moyer (Beamsville, near Niagara Falls in Ontario, Canada) is trying something similar. After seeing his caramel apple business killed overnight when listeria was found in some caramel apples (not his), causing more than 30 hospitalizations. And, it’s not just apples- as we saw above, spinach, melons, lettuce- all these are prone to microbial contamination.
Moyer began playing with UV light and hydrogen peroxide. But, his device looked like a washing machine and got no one’s interest.
Working with Dr. Keith Warriner (School of Food Science, University of Guelph), they advanced the design to include ozone (another strong oxidant like hydrogen peroxide) to produce an antimicrobial mist. Add this concept to a conveyor-belt system, and you can envision their new product.
Using the Clean Works (that’s what they call their invention) system, the mist terminates 99.9% of pathogens, mold, and mildew in under 30 seconds of transport. (This means a 100,000 fold kill.) This augments the shelf life of fruit by about 25 percent.
(This is not an idle claim. Dr. Warriner, along with Drs. M. Hasani, J. Chudyk, K. Murray, L-T Lim, and D. Lubitz presented these results in the journal, Innovative Food Science & Emerging Technologies. The optimum treatment resulted from the combination of 1.88% Hydrogen Peroxide (H2O2, on volume percent), with a UV intensity of 3.26 mW (milliwatts)/cm2, with an applied does of 65.2 mJ (milliJoules)/cm2. (That means a 20 second dwell time.) Oh, yeah- you’re wondering where the ozone was? That is produced by UV-C light when it contacts the oxygen in the air.)
https://cleanworkscorp.com/product/clean-flow-mini/
Right now, Sunkist is examining the process- starting with its lemons. CleanWorks has optimized the system to provide the desired results, without browning the lemons.
(As an aside, you do know that the biggest source of contamination at a bar or a restaurant is when they add lemon to your drink. Those cut lemons just fester and afford microbial growth- not to mention all the finger contacts with the cut lemons.)
By comparison, the water washes that are often used for bagged salad mixes only cut the microbial load by a factor of 10. (I already reported that bagged salads have a problem- the water in the bag actually promotes the growth of the remaining microbes.)
Just so you know, a buddy of mine proposed using radiation to kill off the pathogens. It was far more effective- but consumers are not interested in eating fruit or vegetables that may be radioactive. (They’re not- but you can’t convince folks of that fact.)
I really see this problem with the bagged salads. I love them (because I’m basically lazy when it comes to cutting up all the veggies) but much of the time the lettuce is already wilted and gross. I waste so much throwing them out. They have to be eaten right away or forget it. The “spring mix” is the worst—it often rots before the expiration date on the bag. Yuck.
My ex used to buy those greens- and I would never let the kids partake. (Yes, a big bone of contention.)
There goes my habit of asking for lemon slice in my iced tea. I had no idea. I had food poisoning when I was about 18. I wouldn’t wish it on anyone. A co workers daughter got very sick off the romaine lettuce outbreak last year. This is good news. Wegmans used to sell irradiated ground beef. Not sure they still do. We used to buy it.
Part of these outbreaks result from not following the guidelines we developed decades ago regarding wait times before harvesting crops after irrigation with less than pristine water. The other is bagging the vegetables. WE just need to do a better jovl
It’s scary to read or see so many foods that are contaminated in one way or another. I have heard about the lemons, I don’t use them anymore when eating out.
We need to do a much better job about food safety.
No!! Say it isn’t so. I always ask for lemon to be added to my tea. Yikes!
Not quite the best choice, Jeanine!
Hi Roy
Thanks for another great post that increases our knowledge of what is happening to us in this wonderful world.
Thank you so much for your kind comment!