• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.433-437
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• 2002

Human milk is normally contaminated with various microorganisms, which seem to produce no ill effects. A contamination of hand-expressed and pump-expressed human milk is a major concern in the collection of storage milk. In this study we compared milks collected by two methods, hand expression and suction breast pump, to quantify differences in the degree of bacterial contamination. Thirty-one samples had been manually expressed. The mean of total bacterial counts was 10,600 CFU/mL (range: 360 ∼59,200 CFU/mL) and coliform counts was 43 CFU/mL (range: 20 ∼ 1,060 CFU/mL) in these samples. Whereas in the 118 breast pump-expressed samples, the mean of total bacterial counts was 20,200 CFU/mL (range: 240 ∼ 492,000 CFU/mL) and coliform counts was 158 CFU/mL (range: 4∼10,600 CFU/mL). There was no bacterial growth when the samples were incubated for 10 days at 4$\^{C}$. We also compared total bacterial growth in colostrum and in matured human milk for 24 hr at 20$\^{C}$ and 30$\^{C}$. Although bacterial growth had not shown for 24 hr at 20$\^{C}$, but shown slight growth in colostrum and rapidly increase in matured human milk for 24 hr at 30$\^{C}$. The coliform bacteria in all samples, particulary in formula milk, had grown at 20$\^{C}$ and 30$\^{C}$.