The effect of UV-C irradiation on lipids and selected biologically active compounds in human milk

The effect of UV-C irradiation of human milk on lipid oxidation, content of antioxidants (vitamin C and catalase, CAT) and bactericidal compounds (lysozyme), as well as the total antioxidant capacity (TAC), of the breast milk was investigated. In parallel, the extent of inactivation of some bacteria was also determined. UV-C at doses from 85 to 740 J L−1 caused total inactivation of Escherichia coli and Staphylococcus aureus, but bacteria of the genus Enterococcus were reduced only partially. There was a significant increase in content of primary (lipid peroxides, LP) and secondary (thiobarbituric acid reactive substances, TBARS) oxidation products of lipids (by 33% and 36%, respectively) but decreased vitamin C and lysozyme content (by 35% and 41%). UV-C had no effect on the value of the TAC and caused a smaller decrease in CAT activity (by 14%) than conventional pasteurisation (by 60%).