Objective Pasteurisation can be recommended to inactivate potential pathogens in expressed human milk but important immunological components will be inactivated. We studied the effect of Holder pasteurisation on mannose-binding lectin (MBL) activity and soluble CD14 concentration.
Methods After collection, 38 samples were frozen immediatly at −20°C. Before the laboratory analysis, all the samples were thawed and each sample was divided into two aliquots. One aliquot was pasteurised at 62.5°C for 30 minutes and the other aliquot was kept raw. ELISA were performed on the aqueous fraction. Measurement of MBL activity was done using the Wieslab complement system MBL pathway and was calculated as percentage activity of the positive control (positive control 100%). A quantitative colorimetric ELISA kit was used to assess the concentraton of soluble CD14. Concentrations of sCD14 were calculated using a standard curve.
We did not find a significant difference between MBL activity in pasteurised (12.94 ± 2.1%) versus raw milk (12.47 ± 1.981.98). sCD14 concentrations were significantly lower (p<0.01) in pasteurised milk (see fig). No relationship between activity/concentration and gestation or the stage of lactation was observed.
Conclusions Although the measured activity of MBL was low, there was no difference between pasteurised and raw breast milk. However, pasteurisation significantly reduced the sCD14 concentration in expressed human milk.