State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Research Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China.
J Agric Food Chem. 2020 Jul 8;68(27):7204-7213. doi: 10.1021/acs.jafc.0c02234. Epub 2020 Jun 25.
Goat milk at different lactations show varied lipids distributions, which are potentially dietary influencing factors for the health of human consumers. Herein, the effects of lactation stages (colostral, transitional, and mature stages) on lipid profiling and microstructure of goat milk fat (GMF) were investigated. A total of 359 species of triacylglycerols (TAGs), 27 species of diacylglycerols (DAGs), and 10 classes of phospholipids (PLs) were identified using high resolution tandem mass spectrometry (HR-MS/MS). Of importance, goat transitional milk presented the highest levels of MUFA (29.51%) and lyso-phospholipids (7.95% of total PLs) among these three different lactations. A lactation-dependent attenuation was found at the level of PUFA in goat milk, particularly long-chain PUFA ω-6. Similar behavior was observed in the total proportions of POO (16:0/18:1/18:1) and PSL (16:0/18:0/18:2), presenting a decrease from 3.70% to 3.23% as the proceeding period from colostrum to mature. The relative contents of sphingomyelin and cholesterol in goat colostrum were approximately twice and three times that in mature milk, respectively. Unlikely, both PMCy+MCaM (16:0/14:0/8:0 + 14:0/10:0/14:0) and BuPO (4:0/16:0/18:1) TAGs, the foremost saturated and monounsaturated TAGs in goat colostrum, respectively, showed upward trends over the period from colostrum to mature. Interestingly, no significant variation in milk fat globule morphology was monitored at different lactation periods. Therefore, all our results demonstrated that the main influences of lactation stages on GMF were the lipid profiling, providing a theoretical guidance for rational implement of lipids in goat milk.
不同泌乳期的羊奶表现出不同的脂质分布，这可能是影响人类消费者健康的饮食因素。在此，研究了泌乳阶段（初乳期、过渡乳期和成熟乳期）对羊奶脂肪（GMF）脂质谱和微观结构的影响。使用高分辨率串联质谱（HR-MS/MS）共鉴定了 359 种三酰基甘油（TAG）、27 种二酰基甘油（DAG）和 10 类磷脂（PL）。重要的是，在这三个不同的泌乳期中，羊奶过渡乳表现出最高的单不饱和脂肪酸（29.51%）和溶血磷脂（总 PL 的 7.95%）水平。在羊奶的多不饱和脂肪酸（PUFA）水平上发现了一种随泌乳而减弱的现象，特别是长链 PUFA ω-6。在总比例 POO（16:0/18:1/18:1）和 PSL（16:0/18:0/18:2）中也观察到类似的行为，从初乳到成熟，其比例从 3.70%下降到 3.23%。羊奶初乳中的神经鞘磷脂和胆固醇的相对含量分别约为成熟乳的两倍和三倍。相反，初乳中含量最高的饱和和单不饱和 TAG 分别为 BuPO（4:0/16:0/18:1）和 PMCy+MCaM（16:0/14:0/8:0+14:0/10:0/14:0），这两种 TAG 的相对含量在从初乳到成熟的过程中呈上升趋势。有趣的是，在不同泌乳期，乳脂肪球形态没有明显变化。因此，所有结果表明，泌乳阶段对 GMF 的主要影响是脂质谱，为羊奶中脂质的合理应用提供了理论指导。
