| Human milk is the best source of nutrition for infants. It not only ensures the energy supply for the infant, but also provides a necessary material security to their growth and development. Lipids, about 3 %~5 % of human milk, are the main energy substances. At the same time, there are many important constituents which play important roles in infant’s development. For example, phospholipid, accounting for 0.5 %~1.0 % of total lipids, is one of the vital lipids in human milk. It attached on milk lipid globule membrane and maitain the stability of milk fat. What’s more, it also plays an important role in cell signal transduction and infant’s intelligence development. Lipidomics, an emerging subject, is aimed to systemically study the characters of lipid molecular species in organisms and their roles in regulating protein and gene expression. There are 3 contents including lipid and its metabolites, lipid function and metabolic regulation, lipid metabolic networks and pathways. The purpose of our study is of qualitative and relative quantitative research of phospholipids and fatty acid depending on the method of lipidomics in human milk with different lactation and make a contribution to the study of Chinese human milk phospholipidomics and fatty acid.In our study, human milk including colostrum(1~5 d), transitional(6~20 d) and mature milk(after 21 d) were from Harbin(Heilongjiang province), Qiqihar(Heilongjiang province) and Jilin(Jilin province) and the numbers of samle were s eventy-three. Liquid chromatography-mass spectrometry(UPLC-Triple-TOF-MS/MS) was applied to analyse the profiles of phospholipid. Lipid View 1.2, a kind of application software, was used to retrieve the molecular formula of phospholipids. Peak View 2.2(equipped with Master View? 1.1) and Multi Quant? were used for the qualitation and relative quantitation of phospholipids respectively. At the same time, gas chromatography(GC-FID) was used to analyse the fatty acid profiles in human milk lipid and its polar lipids and the trend of fatty acid in human milk with the lactation was described in order to make a contribution to the study of Chinese human milk lipids.The result showed that there are 62 species phospholipids in Chinese human milk and the species of phosphatidylcholine(PC), phosphatidylethanolamine(PE), phosphatidylserine(PS), phosphatidylinositol(PI) and sphingomyelin(SM) were 19, 25, 4, 5 and 9 respectively. The relative content of phosphatidylcholine(PC), phosphatidylethanolamine(PE), sphingomyelin(SM), phosphatidylserine(PS) andphosphatidylinositol(PI) in total phospholipids were 38.12 %, 26.97 %, 29.54 %, 4.43 % and 0.94 % respectively and various phospholipid in different lactation also showed different trends. In addition, Twenty-seven kinds of fatty acid were detected from human milk polar lipids and there are significant differences between the human milk and polar lipids in the side of species and content. With the change of lactation, we found that the relative content of saturated fatty acid in the transitional milk content is the highest, reaching 39.02 %. Monounsaturated fatty acid relative content in the whole lactation did not differ significantly. Polyunsaturated fatty acids increased from 24.91 % to 29.05 % when the lactation arranged from transition to mature, but the relative content is not differently significant in colostrum and transitional stages.In conclusion, phospholipids in human milk were analyzed qualitatively and quantitatively by lipidomics method and it provides reference data for human milk phospholipidomics. The fatty acids composition in polar lipid and human milk lipid are different significantly and the fatty acid in human milk changed obviously with the the lactation period, this fact should be concerned in the production process of infant formula. |
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