Techniques for the storage of human breast milk: implications for anti-microbial functions and safety of stored milk

Abstract

Storage of human breast milk by freezing or refrigeration of milk with and without heating have been recommended. This can hardly be avoided because of the social circumstances of most mothers who are regularly separated from their infants because of work or schooling as well as the particular needs of some pre-term or sick babies to be fed with expressed breast milk. The greatest fear that has hindered the prospects of in-vitro storage of breast milk for any considerable period of time is the possibility of bacterial contamination and growth of infectious pathogens in the stored milk, thereby rendering them unsafe for human consumption. Bacteriological examination of refrigerated milks has proven their safety for human consumption for even up to 72 h. For a storage over longer periods up to 1 month, freezing at −20 °C could be recommended, but the most preferred method, especially for longer storage would be fresh freezing at −70 °C, if affordable or available. The expressed fears arising from increased titratable acidity of such stored milk samples have been unfounded, since it has been shown to be mainly attributable to levels of free fatty acids, rather than lactic acid, which might have been produced by bacterial fermentation of milk sugars.

Conclusion Evidence shows that temporary storage of human milk under appropriate conditions is not dangerous for babies and infants. This would further encourage the practice of prolonged exclusive breastfeeding and allow the families to reap its multi-fold benefits.