Human milk: Quantitative gas-liquid chromatographic analysis of triglyceride and cholesterol content during lactation.

Gas-liquid chromatography has been used to follow changes in the triglyceride composition of human colostrum and milk from one donor during the first 10 days postpartum and to compare the compositions obtained with those at later stages of lactation.New triglycerides of low molecular weight appeared during the first 5 days postpartum. Lower molecular weight triglycerides (<C(48)) continued to increase until the eighth day. Triglyceride C(48) and total cholesterol content remained almost constant during the period of the study.Comparison of triglyceride fatty acid composition on the third, sixth, and ninth days postpartum showed considerable specificity in all cases, but a tendency for randomization to occur as lactation proceeded.The advantage of triglyceride over fatty acid analysis for this type of investigation is that in the former, new molecules appear. In the latter, only changes in the proportions of fatty acids occur.