OBJECTIVES: Preterm infants are often fed pasteurized donor milk or mother's milk that has been stored frozen for up to 4 weeks. Our objectives were to assess the impact of pasteurization or prolonged storage at -20 degrees C on the immunologic components of human milk and the capability of the different forms of human milk to support bacterial proliferation. MATERIALS AND METHODS: The concentrations and activities of major host defense proteins in the whey fractions of mother's milk stored for 4 weeks at -20 degrees C or pasteurized human donor milk were compared with freshly expressed human milk. Proliferation of bacteria incubated in the 3 forms of human milk was assessed. RESULTS: Relative to freshly expressed human milk, the concentrations of lysozyme, lactoferrin, lactoperoxidase, and secretory immunoglobulin A were reduced 50% to 82% in pasteurized donor milk and the activities of lysozyme and lactoperoxidase were 74% to 88% lower (P < 0.01). Proliferation of bacterial pathogens in pasteurized donor milk was enhanced 1.8- to 4.6-fold compared with fresh or frozen human milk (P < 0.01). CONCLUSIONS: The immunomodulatory proteins in human milk are reduced by pasteurization and, to a lesser extent, by frozen storage, resulting in decreased antibacterial capability. Stringent procedure to minimize bacterial contamination is essential during handling of pasteurized milk.
OBJECTIVES: Preterm infants are often fed pasteurized donor milk or mother's milk that has been stored frozen for up to 4 weeks. Our objectives were to assess the impact of pasteurization or prolonged storage at -20 degrees C on the immunologic components of human milk and the capability of the different forms of human milk to support bacterial proliferation. MATERIALS AND METHODS: The concentrations and activities of major host defense proteins in the whey fractions of mother's milk stored for 4 weeks at -20 degrees C or pasteurized humandonor milk were compared with freshly expressed human milk. Proliferation of bacteria incubated in the 3 forms of human milk was assessed. RESULTS: Relative to freshly expressed human milk, the concentrations of lysozyme, lactoferrin, lactoperoxidase, and secretory immunoglobulin A were reduced 50% to 82% in pasteurized donor milk and the activities of lysozyme and lactoperoxidase were 74% to 88% lower (P < 0.01). Proliferation of bacterial pathogens in pasteurized donor milk was enhanced 1.8- to 4.6-fold compared with fresh or frozen human milk (P < 0.01). CONCLUSIONS: The immunomodulatory proteins in human milk are reduced by pasteurization and, to a lesser extent, by frozen storage, resulting in decreased antibacterial capability. Stringent procedure to minimize bacterial contamination is essential during handling of pasteurized milk.
Authors: N Mohd-Taufek; D Cartwright; M Davies; A K Hewavitharana; P Koorts; H McConachy; P N Shaw; R Sumner; K Whitfield Journal: J Perinatol Date: 2016-06-02 Impact factor: 2.521
Authors: Saad S Al-Shehri; Christine L Knox; Helen G Liley; David M Cowley; John R Wright; Michael G Henman; Amitha K Hewavitharana; Bruce G Charles; Paul N Shaw; Emma L Sweeney; John A Duley Journal: PLoS One Date: 2015-09-01 Impact factor: 3.240