Assessing the potential of UV-C as a nonthermal alternative to pasteurization in milk powder processing at pilot-scale for the retention of nutrients.

This study evaluated UV-C (UV-C) treatment as a non-thermal alternative to pasteurization for cow's milk, with a focus on the retention of nutritionally relevant components during liquid and powder processing. The milk was thermized and subsequently processed either by conventional pasteurization (72°C, 15 s) or UV-C irradiation (3,900 J/m2 at 4°C), followed by evaporation and spray drying. Microbial inactivation, lipase activity, protein denaturation, amino acid profile, in vitro protein digestibility, immunoglobulin A (IgA) and G (IgG), and vitamin stability were assessed. UV-treated milk showed no significant changes in protein denaturation, amino acid profile and in vitro digestibility compared with raw milk. In contrast to pasteurization, UV-C treatment preserved lipase activity in liquid milk, although no residual activity was detected after evaporation and spray drying. Retention of IgA and IgG was significantly higher in UV-treated liquid milk and milk powder than in pasteurized counterparts. UV-C treatment increased vitamin D3 concentration in milk preserving its bio-accessibility. Overall, UV-C processing preserved key nutritional and bioactive milk components supporting its potential application in dairy processing.