Fresh produce is an important vehicle for noroviruses, a group of viruses that are the most common cause of gastroenteritis in developed countries. However, viruses are said to be resistant to cold pasteurization treatments, such as irradiation, which are used to destroy bacteria, molds, parasites, and insects. The irradiation process uses gamma rays or X-rays to destroy these viruses, but at the dose necessary to eliminate them, it can affect the physicochemical properties of fresh products.

Monique Lacroix, researcher at the Institut National de la Recherche Scientifique (INRS), has developed an edible coating based on cranberry juice and citrus extract that makes noroviruses more sensitive to gamma irradiation, allowing them to be eliminated over time that preserves the quality of food, all without risk to consumers.

The expert indicates that the idea is to spray fresh products such as lettuce or strawberries and then treat it with cold pasteurization such as irradiation. The organic acids and polyphenol in cranberry juice and citrus extract would alter the viral protein and help inhibit its activity.

The academic comments that “noroviruses generally require an irradiation dose of three kilograms (kGy), but we have shown that the treatment time is cut in half with this fruit mix spray, which acts as a natural antimicrobial. Using these natural antimicrobials prevents cell breakdown or brown discoloration. "

The Lacroix team is said to be the first to test the blend of cranberry juice and citrus extract in a combination treatment. The professor affirms that "both the juice and the extract have the capacity to eliminate noroviruses when used alone, but when combined with cold pasteurization in the same treatment, the required fruit concentrations are significantly lower."

The graduate in applied microbiology at INRS and first author of the study, Alexandra Gobeil, assures that “unlike bacteria, noroviruses do not multiply in food. They are deposited there and remain there until a human being is infected. ”

Lacroix and his team have tested the lettuce coating, which is said to be one of the most fragile vegetables in terms of preservation. She said she hopes to eventually develop a partnership with the food industry to test treatment combinations involving natural fruit extracts and cold pasteurization (for example, UV-C, X-ray, gamma-ray, or ozonation) on a commercial scale.