By Danny Bayliss, New Technologies Lead - 15 December 2020

As businesses look for new ways to combat the virus that causes COVID-19, the application of ultraviolet light has seen an incredible uptake. Ultraviolet (UV) light technologies have been around for a long time, but only in the past few years has the food and drink industry really taken an interest in it. As this technology grows in popularity, it’s important to build your understanding of how it can be applied safely and how it can help you.

Before we delve any deeper, for those unfamiliar with UV light it’s worth covering the basics. UV light is part of the electromagnetic spectrum and similar to the light we see with our eyes, but with shorter wavelengths. There are three types: UV-A, B and C. It is the UV-C light that we use as a germicide due to its specific wavelength’s (200 – 280 nm) effectiveness at inactivating microorganisms – making it ideal for decontamination applications in the food industry.

How UV-C light helps the industry

UV-C light was first used to kill bacteria in 1873, and since then we’ve learnt of its vast number of potential applications. Most notably, its germicidal qualities have been investigated and exploited. The non-ionising light can inactivate viruses (including SARS-CoV-2 that causes COVID-19), bacteria, yeast, moulds and spores. How? The UV-C light is absorbed by the microorganism’s DNA, changing the genetic material’s structure and preventing it from replicating. As a result, the organism dies.

UV-C light can be used on a variety of food products to help:

• improve quality
• extend shelf-life, or
• reduce water and chemical usage while also reducing a product’s microbial level.

Its applications are diverse. For example, at Campden BRI we’ve used UV-C light to treat a range of products and surfaces to validate them against pathogen inactivation. More recently we have been exploring UV-C light for in-pack surface decontamination and nutrient boosting applications.

Using UV-C light for zonal transfer – what are the requirements?

The use of UV light to treat items being moved from a low risk area to a high care or high risk area is growing in the food industry. This application, which decontaminates products so that there is a reduced chance of pathogens entering these zones, is becoming common practice for some food businesses. However, it’s important to note that manufacturers must have their UV light systems validated if used for this purpose. Otherwise they may not be compliant with BRCGS Global Standard for Food Safety Issue 8.

Section 8.1.3 of this standard states that, “Where physical barriers are not in place, the site shall have undertaken a documented risk assessment of the potential for cross-contamination, and effective, validated processes shall be in place to protect products from contamination.” While this sounds straightforward, much of the data that exists in literature has been established with water and air. For zonal transfer, the different surfaces and organisms of concern need to be tested to ensure the systems are performing correctly. Need help with this? With extensive experience in UV-C light systems, our team at Campden BRI can provide you with support in this area.

It’s also worth noting that - due to differences in their DNA, external structures, pigments and repair mechanisms - different microorganisms have varying levels of susceptibility to UV light. So, before validating your systems, you should first consider your target organisms so you know the correct dosages to validate them against.

What are the limitations of this technology?

As it’s light-based, UV-C systems must be able to ‘see’ the organisms to inactivate them. So it goes without saying that shadows and shields dramatically reduce this technology’s effectiveness, as well as the structure of the surface you are treating. For example, perfectly smooth plastic sheeting may be easy to treat, but if it’s crimpled beforehand then this will create tiny pockets of cover and protection for the target organisms.

Need help with your UV light systems?

Our experts have in-depth knowledge of many new technologies used in the food industry and are perfectly equipped and positioned to support you with your UV light needs. Whether this is further guidance, advice or testing with UV-C systems, please get in touch – we’d love to help.

Danny Bayliss
+44(0)1386 842130
danny.bayliss@campdenbri.co.uk

About Danny Bayliss

After finishing his PhD in cold plasma technology, Danny joined Campden BRI where he has been in various new technology roles since 2012. Danny currently explores future trends and technology developments where he works with spin off, startups and equipment companies to explore commercial applications or develop technologies for industrial future needs. Danny manages more complex contract trials and works on bigger research projects with multiple consortium members.

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