Advances in Ultraviolet Technology for Food Processing: Engineering, Matrix-Driven Design, and Future Directions

Abstract

Ultraviolet (UV) irradiation is a non-thermal technology of increasing relevance for extending food shelf life while offering economic, technical, environmental, and food-safety advantages. Contrary to common assumptions, its efficacy does not depend solely on lamp nominal power, exposure time, or the apparent penetration capacity of UV radiation. It depends instead on the interaction among the emission wavelength, incident fluence, food optical and physical properties, reactor geometry, and hydrodynamics, which together determine the UV distribution, transmission, scattering, and absorption in food matrices. Therefore, this review analyzes UV processing from an engineering perspective by integrating photochemical principles, germicidal mechanisms, UV sources, reactor configurations, mathematical models, and food applications. The discussion emphasizes the main barriers to industrial scale-up, including limited optical penetration, heterogeneous fluence distribution, absorption by food constituents, shadowing in irregular solids, regulatory constraints, UV-LED power and thermal-management limitations, and the balance between microbial inactivation and preservation of bioactive compounds. In addition, engineering variables, optical properties, radiation-distribution models, and reaction-kinetic approaches are synthesized to standardize useful criteria for designing, optimizing, and validating UV processes. Finally, a food-matrix-driven decision framework is proposed to guide the selection of photoreactors, critical variables, and validation goals for different food decontamination and processing purposes.