Light-Based Technology in Food Safety

Food science researchers are exploring how light-based technology can be used to ensure the safety and quality of liquids such as fresh juice and milk.

Tatiana Koutchma, PhD, who participated in a panel discussion at the Institute of Food Technologists conference this summer in Chicago, says that light-based technologies “are very powerful for selected applications but more research needs to be done. These technologies are still on their way to commercialization.”

A research scientist in novel food processing at Guelph Food Research Center, Agriculture and Agri-Food Canada, Dr. Koutchma says she is investigating how UV treatment “affects the quality, nutritional content, and color of fresh juices” by comparing light-based technology with high pressure processing.

Research published by Dr. Koutchma and colleagues in the August 2015 issue of the Journal of Dairy Science investigated the chemical changes in raw milk composition after exposure to a new non-thermal turbulent flow UV process. The researchers pointed to the need for an alternative process that would be less costly than traditional pasteurization methods for producers who work with smaller volumes of milk.

Their research found that the technology produced no change in raw milk in terms of total fat, protein, carbohydrates, moisture, ash, the fatty acid profile, or the oxidation or protein profile. They concluded that turbulent flow UV technology could be an alternative non-thermal method for extending the shelf life of pasteurized milk and raw milk.

Kathiravan Krishnamurthy, PhD, assistant professor in the department of food science and nutrition at Illinois Institute of Technology and another participant on the panel, says that light-based technologies are very promising because they are cost effective, can easily be integrated into existing food processing operations, and can ensure food safety without compromising the quality of most foods.

However, more research is needed related to the penetration depth capability of the technology. “The intensity of light decreases exponentially as a function of food depth, and it also significantly changes based on the transmissivity of the food product. Therefore, penetration depth is a major limiting factor for the light-based technologies,” Dr. Krishnamurthy says.

“Light-based technologies are typically not an effective solution for treating opaque liquid foods and the internal content of solid foods,” he continues. “They are effective for surface decontamination of solid foods and decontamination of reasonably clear liquids.” Treatment of opaque liquids has been found moderately successful if the liquid is treated as a thin film and/or by using turbulent flow, he says. Systems are needed that “allow 360 degrees of the product to be exposed to light.”