Ultraviolet radiation: An interesting technology to preserve quality and safety of milk and dairy foods

Background: Thermal processing is the most common decontamination method used in the dairy industry to ensure food safety and extend shelf life. However, due to the increased consumer demand for more natural and healthier products, nonthermal technologies have been intensively studied. Irradiation with shortwave ultraviolet light (UV-C) offers some technological advantages due to its low maintenance and installation costs, minimal energy use, and food preservation without some undesirable effects of heat treatments. Scope and approach: This review aims to describe the theoretical fundamentals of UV-C radiation and approaching the critical processing factors involved. Also, it describes the mechanisms of microbial inactivation and provides an overview of the effects on dairy product quality, considering microbiological, physicochemical and sensory aspects. Key findings and conclusions: UV-C radiation can be considered an effective method for inactivating pathogenic and spoilage microorganisms in milk and dairy products by forming lesions in DNA and/or damage in the cellular enzyme activity and cytoplasmatic membrane integrity. The efficiency of the process is dependent on the process parameters (time of exposure, UV dose, wavelength and UV light source), product type (chemical composition, viscosity, turbidity, opacity and roughness), equipment (conformation and geometry), and microorganism characteristics (specie, strain, initial count, growth phase, and recovery conditions). When optimum conditions are applied, there is no impact on the physicochemical, nutritional and sensory aspects. In conclusion, UV-C can be considered an environmental-friendly emergent non-thermal technology for decontamination of dairy products, presenting low costs and efficiency in the maintenance of the quality parameters of dairy products.