Ultraviolet light used in food processing is most effective against which type of contamination?

• A. Bacterial spores
• B. Yeasts
• C. Molds
• D. Surface or airborne bacteria

Answer: (D)

Ultraviolet light used in food processing works by damaging the DNA of microorganisms, preventing them from replicating. Because UV light does not penetrate solids well, it only affects organisms that are directly exposed on surfaces or in the air. This makes it particularly effective for sanitizing exposed surfaces and disinfecting air streams in processing environments. Bacteria on those exposed surfaces or in the air are reliably inactivated with UV, whereas spores—being highly resistant due to protective coatings—are much less affected, and microorganisms hidden inside food particles or crevices aren’t reached by the light. Yeasts and molds can be damaged by UV too, but the most consistent, dependable results come from targeting surface or airborne bacteria.