A simple system for measuring the level of free fatty acids in human milk collected as dried milk spot

This study aimed to develop a robust dried milk spot (DMS) system where fats in the breast milk are stable at room temperature, and the FFA concentration of the milk can be accurately measured without interference by the high level of triglyceride, which normally constitutes around 98% of the fats in fresh milk. Our system involves applying a small amount breast milk (20µL) on silica gel impregnated filter paper and microwaving at high power to denature lipases. At the time of analysis, the milk fats are eluted with acetone, re-constituted in heptane and injected directly into a gas chromatograph equipped with an acid modified polyethylene glycol column. This DMS method was validated against the conventional TLC method across a range of FFA concentrations. The breast milk fats collected using this DMS system are stable at room temperature for at least eight weeks which allows for transportation by post and has the potential for use in multi-centred international clinical trials.Current dried milk spot (DMS) technology is limited to measuring the fatty acid composition of the total fats in breast milk, but not its free fatty acid (FFA) concentration. This study describes a new DMS system whereby milk fats can be stabilised at room temperature for long periods and the level of FFA can be accurately measured in the presence of other fats. Breast milk fats were stabilised by inactivating endogenous lipases via microwaving; the fats were then eluted, re-constituted and injected i...
Source: Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA) - Category: Lipidology Source Type: research