By Dr. Suzanne Osborne
A new twist on an old technology means the food industry could soon harness greater benefits from ultraviolet (UV) light. Although it’s been used to fight foodborne illness for more than 50 years, new research is showing it can be a more practical choice for widescale use.
Light travels in waves and is classified by the distance between each wave. Any light waves that range between 10 nanometres (nm) and 400nm apart are considered UV. Humans might not be able to see UV light—it sits just outside our visible range—but it can penetrate our skin and eyes and trigger chemical reactions. Short exposure will cause pain and redness (sunburn); exposure over long periods of time can lead to skin cancer, accelerated skin aging, and cataracts.
The beauty of UV light is that it can eliminate pathogens without chemicals, by-products, or changes to the properties of the food.
Bacteria and viruses have thinner cell barriers compared to human cells. The human body is further protected by the multiple layers of cells that make up our skin. Because of this, as light waves become closer to a distance of 200nm apart, humans can withstand UV light, while pathogens are killed.
The beauty of UV light is that it can eliminate pathogens without chemicals, by-products, or changes to the properties of the food. It is relatively cost effective, efficient, and highly compatible with other treatment processes. Its main drawback for years has been its limited penetration depth, and so UV sterilization has generally been limited to decontaminating surfaces, the air, and clear liquids.