Wpływ liofilizacji mleka ludzkiego na wybrane biologicznie aktywne składniki (witamina C, katalaza, lizozym), ogólną zdolność przeciwutleniającą oraz utlenianie lipidów

Abstract

Human milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled date and without complications. Freeze drying resulted in the removal of 88.2 % of the initial water content from milk. The human milk lyophilizate was readily soluble in water. Lyophilization had no effect on the content of primary (lipid peroxides LP) and secondary (thiobarbituric acid reactive substances TBARS) products of lipid oxidation. Freeze-drying led to a significant decrease in the vitamin C content and TAC values of milk (by 31 % and 16.5 %, respectively). Catalase and lysozyme were resistant to freeze-drying. Lyophilization induced a decrease in lysozyme content (9 %) and catalase activity (11 %) but these changes were not statistically significant. Low-temperature dehydration and rehydration of human milk lyophilizates promote satisfactory retention of biologically active ingredients and prevent the oxidation of human milk lipids. The results of this study indicate that lyophilization can be considered as an effective method for prolonging the shelf life of human milk.