Aim Storage of human milk in refrigerator has been recommended for short term storage. It has been shown that some nutritional, immunological, bioactive properties and bactericidal activity of human milk can alter by refrigeration. Pyrex bottles and polyethylene bags are the two common containers in the setting of storage of human milk. The aim of this study is to compare the effect of the type of storage container on bactericidal activity of human milk at different duration of refrigeration.
Methods Forty four samples of human milk were collected from 22 lactating mother. Two samples of human milk were obtained by manual expression from each mother. One was collected directly into sterile pyrex bottles and the other into polyethylene bags. Each sample was divided into three aliquots, one was processed immediately and remaining two were kept at 4°C for 24 and 48 hours. Bactericidal activity of each sample was studied. A strain of E.coli ATCC 25922 was used to determine the bacteridal effect of human milk.
Results Bactericidal activity was significantly reduced in milk samples kept in polyethylene bags compared to the samples kept in pyrex bottles when milk samples stored at 4°C for 24 and 48 hours (p<0.05).
Conclusion Short term storage of human milk in pyrex bottles is more appropriate than polyethylene bags for prevention of decrease in bactericidal activity.