LAUSR

Abstract Concentrations of five phospholipid (PL) classes and their respective molecular species were determined in mature milk samples from a cohort of Chinese mothers over an eight month lactational period. Although changes were not statistically significant, average total PL concentrations increased over the mature milk period from a one month low of 193 mg L−1 to a high of 246 mg L−1 at eight months lactation. Phosphatidyl ethanolamine (37% of total PLs) was the most abundant phospholipid class throughout the mature milk period, followed by sphingomyelin (32%), phosphatidyl choline (22%), phosphatidyl serine (4%) and phosphatidyl inositol (3%). The molecular species 36:2 was identified as the most abundant for the glycerophospholipids, ranging from 37% to 64% of the total molecular species intensities, and lactational changes in this molecular species dominated the overall lactational changes in proportions of molecular species. At 20.6%, the molecular species d40:1 was the major sphingomyelin molecular species identified.