Food Phytochemistry Department, Instituto de la Grasa (CSIC), Campus Universitario Building 46, 41013 Sevilla, Spain.
Food Lipid Biomarkers and Health Group, Institute of Food Science Research (CIAL, CSIC-UAM), 28049 Madrid, Spain.
Molecules. 2021 Mar 30;26(7):1935. doi: 10.3390/molecules26071935.
Several studies have been published regarding the effect of different factors on the digestion of milk lipids, considering their natural structural arrangement as milk fat globules and the efficiency of the digestive enzymes in the lipolysis of such complex structures. During digestion, the lipolytic products are dispersed in vesicles and micelles, which are the source for absorption of digested lipids. Therefore, it is necessary to consider the isolation of the micellar phase from the digesta to appropriately determine the amounts and classes of lipids which are bioaccessible. This study presents an integrative approach that included an isolation procedure to separate the micellar fraction from undigested and non-micellar parts, and the distribution of digested milk lipids in micelles determined directly through chromatographic techniques. Four groups of five full term mothers donated colostrum or mature milk. Two sets of samples were analyzed directly (raw), and two sets were pasteurized and then analyzed. Our data revealed that the profile of digested milk lipids is different depending on the lactation period and processing stage, while the carbon atom number distribution of the digested triacylglycerols in the micellar fraction provides a substantial information regarding the acylglycerols species that are less available for absorption.
已有多项研究针对不同因素对乳脂消化的影响进行了报道，因为乳脂是以天然的乳脂球结构存在的，而消化酶在这种复杂结构的脂解中效率也不尽相同。在消化过程中，脂解产物分散在小泡和胶束中，这些小泡和胶束是消化后脂类吸收的来源。因此，有必要从消化物中分离胶束相，以适当确定生物可利用的脂类的数量和类别。本研究提出了一种综合方法，其中包括一种分离程序，用于将胶束级分与未消化和非胶束级分分离，并通过色谱技术直接确定消化乳脂在胶束中的分布。四组五名足月母亲捐献初乳或成熟乳。两组样品直接进行分析（原样），两组样品经过巴氏杀菌后再进行分析。我们的数据表明，消化乳脂的分布图谱取决于泌乳期和加工阶段，而胶束级分中消化三酰基甘油的碳原子数分布为那些生物利用度较低的甘油酯种类提供了重要信息。
