Publications

Ultraviolet (UV-C) treatment is a proposed alternative to conventional high temperature-short time (HTST) processes for milk pasteurization. However, little information is available on its impact on the chemical composition of milk, as well as a comparison with HTST treatment. Consequently, the aim of this study was to compare the effects of HTST (72 °C, 16 s) and UV-C (coil diameters of 5- and 7-mm, 1 or 2 passes) with turbulent flow on the proximate composition, protein profiles and surface properties, as well as off-flavor development in whole milk (WM), skim milk (SM), skim milk generated from whole milk (SM_WM), and whey protein concentrate (WPC). Our results on proximate composition showed that only the UV-C treatment with 2 passes using a 7-mm coil resulted in lower lipid content in SM_WM compared to HTST. Protein profiles, free thiol content, surface hydrophobicity, and aromatic amino acid levels remained similar between the control, HTST and UV-C treated samples. However, higher alcohol levels were detected in HTST-treated samples, while UV-C-treated dairy fluids had increased levels of free fatty acids and ketones. In addition, hexanal concentration increased only after HTST treatment of WM. This study highlights the potential of UV-C treatment in the dairy industry, demonstrating its ability to preserve nutritional quality while also offering valuable insights into lipid oxidation and the formation of light-induced off-flavor compounds.