Lipid composition and vitamin E content in human colostrum and mature milk.

Abstract

Lipidic components, as well as fatty acid composition and vitamin E content were determined in colostrum (days 3-5 of postpartum) and mature milk (day 21) in 8 women from Murcia (Spain). Triglycerides concentration was higher and cholesterol and estcrificd cholesterol ,vcre lower in mature milk than in colostrum, whereas phospholipid content was similar. These differences indicate that the diameter oi milk fat globules increases in mature milk. The percentage oi medium-chain fatty acids (12:0 and 14:0) increased in mature milk as compared to colostrum, reflecting de no·vo svnthesis of fatty acids. With the only exception of stcaric acid which was lower in mature milk than in colostrum, the remaining long-chain fatty acids was similar. The proportion of both linoleic (18:2) and eicosapcntaenoic (20:5) acids found in mature milk and colostrum is higher than in studies from other countries and mav reflect the intake of high proportions of polyunsaturated fat from vegetable oils and fish in the studied women. Both vitamin E content and vitamin E/linoleic acid ratio in mature milk arc lower than in colostrum, evidencing the efficient mechanism of mammary gland vitamin E uptake around parturition.