Combined effects of UV-C pretreatment and subsequent pasteurization on the alteration in bovine milk metabolomic profile

Abstract

This study investigated the impact of ultraviolet-C (UV-C) irradiation in combination with pasteurization on the variation in bovine milk metabolite composition. Raw milk was pretreated with UV-C (253 nm) at two different doses (0.95 and 2.20 J L⁻¹), followed by pasteurization, to assess how exposure intensity and processing sequence influence metabolite composition. A total of 45 non-volatile metabolites were identified using¹H NMR metabolomics approach. Multivariate analysis revealed distinct metabolome patterns among untreated, different UV-C-treated, and pasteurized milk samples, highlighting treatment-dependent alterations. The higher UV-C irradiation dose (2.20 J L⁻¹) resulted in more pronounced metabolite losses in raw milk, attributable to intensified photochemical degradation. Although the combination of UV-C and pasteurization produced cumulative metabolite reductions, notably, UV-C treatment at the lower dose (0.95 J L⁻¹) appeared to sensitize milk metabolites to subsequent heat-induced degradation. These findings provide insights into how combined UV-C and thermal treatments impact milk metabolomic profile, emphasizing the necessity for further process optimization.