UVC and Foodborne Pathogens

With over 25 years of experience, UV Photons manufactures and develops premium handheld and mountable disinfection lamps, smart mobile robots, and precision UV measuring equipment.


It really works when UVC runs. When used properly, it can kill up to 99 per cent of pathogens. This is why UVC treatment has been used for sterilising equipment in clinical and laboratory settings for many years. It's only in the last few years that UVC has started to take off for personal use, especially given the current COVID-19 pandemic.

 

But in various contexts, there are a lot of legitimate questions and concerns about the safety of using UVC disinfection. And so rightfully. UVC is an exceptionally strong form of ultraviolet radiation that, when not used correctly, can be dangerous to humans. We are almost never exposed to these high-frequency light waves because almost all the UVC emitted by the sun is blocked by the atmosphere. However, in mere minutes, exposure to artificial UVC light can cause sunburn.

Whether it can be used safely to disinfect food is one of the safety concerns that have emerged around UVC. The answer depends on how you use it, as is the case for most UVC applications.

 

UVC Has Been Shown to Kill Food-borne Pathogens

There is little doubt that the bacteria that can cause food-borne diseases can be killed by UVC light. UVC can kill almost all living cells. The challenge of using UVC for food-borne pathogens, however, is ensuring that the pathogens are exposed to them.

UVC has been shown to kill pathogens on the surfaces of fruits in laboratory settings. A Washington State University study exposed apples, pears, strawberries , raspberries, and cantaloupe to different intensities of UVC light. They discovered that UVC was able to kill about 99.9% of E. On the surfaces of the fruit, coli and Listeria bacteria.

Importantly, UVC light in the food itself also causes little perceptible change. UVC is really dangerous only when the light rays themselves are exposed to you. It leaves no residue. So in consuming food that has been exposed to UVC light, there is virtually no danger.

 

UVC Can Also Help Improve Shelf Life

UVC can be helpful in increasing the shelf life of natural food products, just like any method of disinfection. The potential of UVC and cooling to alter the shelf life of various fruits was examined in another, more recent study. They found that the shelf life of the fruits was extended by both methods. Slight changes in the levels of antioxidants in the fruits were also caused by UVC, enriching them in some but reducing their capacity in others. The broader outcome, however, is that UVC can be used to keep foods fresh longer because it has powerful disinfection properties. This is particularly important for organic farmers and distributors, because one of the main challenges of producing food without chemical additives is the maintenance of shelf life.

 

Challenges of Using UVC for Food

In general, the biggest challenge with UVC is ensuring that the desired surfaces are adequately exposed to light. UVC only works when pathogens are bathed in light waves of UVC, which in a food processing context can be difficult to implement.

 

There are often textured surfaces in foods that create microscopic shadows where microbes can hide. To ensure that all surfaces are exposed, rotating footings under light can mitigate this. In addition, UVC can't sterilise a large pile of food efficiently. A rotten apple at the bottom of a large barrel, even if the barrel is exposed to UVC light, will still cause others to rot. In order for UVC to be successful, food must be adequately spread out, so it must be worked into the appropriate production process depending on the product.

For instance, before they are grouped together for shipment, UVC will work better at disinfecting apples.

Another challenge is that in cold and moving air conditions, some UVC systems , particularly older ones, lose some of their effectiveness, i.e. precisely the kinds of conditions present in most food processing and packaging processes.

However, this issue is addressed by more advanced goods by novel mechanisms that can differ with the form of food being disinfected. For example, the extended protective version of the UV Photons C110 P series uses special UV-C lamps covered in a UVC FEP cover to shield the lamps from shattering glass, offering an ideal solution for disinfecting food processing plant applications.

So, as with any UVC system, adapting your system to your circumstances and needs is the most important way to ensure its effectiveness. But UVC provides a safe and effective means of sanitising food and other surfaces with the correct setup. Click here to visit our Products Page to explore UVC systems from UV Photons.