Loss of viability and metabolic injury of Staphylococcus aureus resulting from storage at 1 degree, 3 degrees, 5 degrees and 7 degrees C

Collecting and banking human milk: to heat or not to heat?

Data on human breast milk and its handling when fed to babies who cannot be breast-fed were reviewed to determine whether the method of processing and storage affected the properties of the milk. Breast milk is normally contaminated by potential pathogens, which seem to produce no ill effects, but it also contains antimicrobial properties which protect against infection. The evidence suggests that pasteurisation not only eliminates pathogenic bacteria but also damages bacteriostatic mechanisms, so making the milk more susceptible to later contamination. Pasteurisation also affects the nutritional properties of milk. Freezing has little effect on milk proteins, while a study on the effect of refrigeration showed that there was little bacterial growth at temperatures below 8 degrees C. Several years' experience of feeding donated raw milk to newborn infants has confirmed that it produces no ill effects. These findings suggest that pasteurisation of donated breastmilk is unnecessary, and it is not recommended, while the decision whether or not to freeze the milk may be made on practical grounds. Raw breast milk can be safely stored at 4-6 degrees C for 72 hours.