BEVERAGES By Tatiana Koutchma, Ph.D.
Advances in UV-C Light Technology
Improve Safety and Quality Attributes of
Juices, Beverages, and Milk Products
The growing consumption of premium cat- egories of dairy, fruit, and vegetable beverages has been attributed to the perceived health benefits of the “all natural,” “made of organic
ingredients,” reduced-calories, and reduced-sugar messages based on high levels of enzymes, nutrients, and bioactive constituents.
To achieve these attributes, the products have
to be minimally processed in terms of treatment temperature
and exposure to oxygen. For instance, the growth of the cold-
pressed juice industry from local into regional and national
markets required higher stability, safety, and extension of
product shelf life to at least a few weeks. Thermal pasteuriza-
tion is an effective preservation technique but often negatively
impacts both nutritional and quality parameters. An alterna-
tive nonthermal processing strategy is the use of high-pressure
processing (HPP). However, HPP is associated with high start-
up and operational costs and batch processing
while also requiring a large amount of space
and use of plastic packaging.
Ultraviolet-C (UV-C) light is another
emerging nonthermal alternative that offers
less expensive, energy-saving continuous treat-
ment and packaging flexibility. Also, UV-C
at 254 nm is effective against all foodborne
pathogens, natural microbiota, molds, and yeasts, with mini-
mum impact on quality and nutritional attributes.1 To achieve
high efficacy of UV-C processing in products with low UV
transmission (UVT), such as the majority of juice and milk
products, new engineering approaches have been developed
that differ from those normally employed for water treatment.
In case of water, UVT achieves values of 90 percent and high-
er; for clear juices, the UVT is typically less than 30 percent
and reaches 0 for turbid juices with particles. Due to the low-