Ultraviolet (UV) technology holds promise as a low cost non-thermal alternative to heat pasteurization of liquid foods
and beverages. However, its application for foods is still limited due to low UV transmittance (LUVT). LUVT foods
have a diverse range of chemical (pH, Brix, Aw), physical (density and viscosity) and optical properties (absorbance and
scattering) that are critical for systems and process designs. The commercially available UV sources tested for foods
include low and medium pressure mercury lamps (LPM and MPM), excimer and pulsed lamps (PUV). The LPM and
excimer lamps are monochromatic sources whereas emission of MPM and PUV is polychromatic. The optimized design
of UV-systems and UV-sources with parameters that match to specific product spectra have a potential to make UV
treatments of LUVT foods more effective and will serve its further commercialization. In order to select UV source for
specific food application, processing effects on nutritional, quality, sensorial and safety markers have to be evaluated.
This paper will review current status of UV technology for food processing along with regulatory requirements.
Discussion of approaches and results of measurements of chemico-physical and optical properties of various foods (fresh
juices, milk, liquid whey proteins and sweeteners) that are critical for UV process and systems design will follow.
Available UV sources did not prove totally effective either resulting in low microbial reduction or UV over-dosing of the
product thereby leading to sensory changes. Beam shaping of UV light presents new opportunities to improve dosage
uniformity and delivery of UV photons in LUVT foods.