Follow Us on Google
By Kingsley Alumona
Over the years, blue light has shown significant results in killing bacteria, but not much is known about its ability to kill viruses because, unlike bacteria, viruses do not possess internal structures which act as photosensitizers, thereby causing bacterial inactivation on exposure to blue light. This is a major concern to the public because current inactivation methods for viruses have several limitations when applied to foodborne viruses.
Munachimso Ugo-Ukegbu, a Nigerian-born, United States-based food safety and quality assurance specialist, is one of the food scientists working in this line of research of utilising blue light to inactivate foodborne viruses.
After graduating from the University of Ibadan with a Bachelor of Science (BSc) in Chemistry, she moved to the University of Georgia, United States of America, where she obtained the Master of Science (MSc) in Food Science and Technology, acquiring along the way expertise in food safety systems, quality management, and regulatory compliance.
She currently works in the US at King’s Hawaiian as a quality assurance supervisor, where she serves as the food safety and quality assurance specialist, ensuring compliance with the US Food and Drug Administration (FDA), the Food Safety Modernisation Act (FSMA), Safe Quality Food (SQF), and other Good Manufacturing Practice (GMP) standards.
“I am deeply passionate about ensuring the safety and quality of foods produced and consumed. I enjoy exploring the science behind how food is produced, why it behaves the way it does, and how it impacts health, culture, and everyday life,” she said.
For her MSc project work at the University of Georgia, completed and successfully defended in May 2025, she worked on: ‘Inactivation of Tulane virus, a human norovirus surrogate, and hepatitis A virus on stainless steel and in freshwater microcosms using 405 nm blue light’.
Each year, foodborne viruses cause illness in millions of people globally. Ugo-Ukegbu noted that her MSc work is an intervention against viruses transmitted through food, water and contaminated food-contact surfaces. She explained that human norovirus (HuNoV) and hepatitis A virus (HAV) are among the most prevalent viruses associated with foodborne and waterborne illnesses.
Norovirus alone is responsible for more than 685 million cases of illness and about 200,000 deaths globally every year. In the United States, it causes more than half of reported foodborne disease outbreaks and is associated with an estimated 19–21 million cases of acute gastroenteritis and 56,000-71,000 hospitalisations annually. The consequences extend beyond illness and death. Norovirus has been estimated to impose an annual global economic burden of approximately $60.3 billion in societal costs and $4.2 billion in direct healthcare costs, highlighting the enormous economic implications of viral foodborne diseases.
The risk is particularly prevalent in fresh fruits and vegetables that are commonly eaten raw, including lettuce, strawberries and other berries. This makes preventing contamination and finding effective interventions before these foods reach the consumer particularly important.
Food safety systems already rely on different chemical and non-chemical disinfection technologies. Other technologies, including ultraviolet light, ozone, and hydrogen peroxide vapour, have also demonstrated effectiveness. However, some applications have operational limitations, including severe safety hazards upon exposure to humans.
According to Ugo-Ukegbu, this raises an important scientific question: could visible blue light provide another tool for controlling viruses in food-related environments? This led to her research, which focused on Tulane virus (TV), a surrogate of human norovirus and hepatitis A virus. She investigated the viruses under two conditions with direct relevance to food safety: stainless steel and freshwater.
Stainless steel is extensively used for food-processing equipment and food-contact surfaces, making contamination of these surfaces an important consideration in preventing the movement of pathogens through food-production environments. Freshwater presents another critical challenge. Water can become contaminated with enteric viruses and, when contaminated water comes into contact with crops during agricultural production, it can provide a route for pathogens to enter the food chain.
In the laboratory, Ugo-Ukegbu exposed virus-contaminated stainless-steel surfaces, sterile water spiked with photosensitizer, and raw freshwater collected from three natural ponds in Georgia to 405 nm blue light. Untreated samples were maintained as controls, while established cell-culture methods were used to determine whether the viruses remained infectious after treatment. The research also examined naturally occurring bacteria in the pond water and monitored important water-quality characteristics to understand whether blue-light treatment produced broader changes in the freshwater environment.
The study demonstrated that 405 nm blue light could reduce the infectivity of the foodborne viruses investigated, although its effectiveness varied depending on the virus and the environment in which it was present. One of the most significant observations was that HAV was considerably more susceptible to blue-light treatment in freshwater than TV. The type of water also influenced the effectiveness of the treatment against hepatitis A virus, demonstrating that environmental conditions can play an important role in how viruses respond to blue light.
“The study reports itself as the first research to explore varying doses of 405 nm blue light against both viruses on stainless-steel surfaces and in raw freshwater sources. This distinction is important because the research connects two potential points of contamination within the food chain: water at the agricultural-production stage and food-contact surfaces during food processing,” she added.
Furthermore, the findings from her work established scientific evidence supporting blue light’s potential as an integrated intervention in viral inactivation on stainless steel and freshwater and identified areas where the technology needs further development.
She noted that future research could investigate higher blue-light doses, different photosensitising compounds, and treatment conditions that more closely reproduce commercial food-processing and agricultural environments. Currently, further research of the use of blue light in activating foodborne viruses at different treatment conditions is being carried out at Esseili’s Lab (Centre of Food Safety, Griffin).
Similar works by other researchers support Ugo-Ukegbu’s findings. M. Sadraeian and others, in their 2022 paper titled ‘Viral inactivation by light’, published in eLight, highlights the anti-viral utility of radiant methods from the aspects of ionising radiation, including high-energy ultraviolet, gamma ray, X-ray, and neutron, and non-ionising photo-inactivation, including lasers and blue light.
Sadraeian and others stated that in contemporary times, viral infections are one of the greatest challenges for medical sciences and human society. They added that while antiviral compounds and chemical inactivation remain inadequate, physical approaches based on irradiation provide new potential for prevention and treatment of viral infections, without the risk of drug resistance and other unwanted side effects.
“For countries where access to safe agricultural water and effective food-safety infrastructure remains a challenge, developing practical interventions for reducing pathogens before they reach consumers could have significant public-health and economic implications,” she said.
Munachimso Ugo-Ukegbu’s research has contributed to the global effort of safely reducing the human and economic burden of foodborne disease while opening a new area for further research into visible-light applications in food and water safety.
Kingsley Alumona, journalist and writer, is based in Ibadan.
