Verveld Wietske, de Wolf Johanna R, Legtenberg Chris G, Knop Tom, Bosschaart Nienke
Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, the Netherlands.
Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, the Netherlands.
Food Res Int. 2024 Dec;198:115282. doi: 10.1016/j.foodres.2024.115282. Epub 2024 Nov 7.
Milk fat globules (MFGs) in human milk provide energy to breastfed infants and support infant development. Accurate measurements of MFG size distributions are important to better understand MFG function and origin, as well as the influence of MFG size on milk composition analysis methods. Nevertheless, commonly used laser diffraction systems have never been thoroughly validated for size distribution measurements in human milk. Here, we introduce a new method for determining the size distribution of milk fat globules in human milk, using 3D confocal laser scanning microscopy (CLSM) in combination with fluorescent labeling of MFGs. We validate and compare 3D CLSM to laser diffraction (Mastersizer 2000, Malvern Panalytical), using polystyrene microsphere size standards. Next, we apply both methods to evaluate MFG size distributions in human milk. We show that 3D CLSM can be used to obtain more accurate size distributions between 500 nm and 10 μm compared to laser diffraction. Importantly, MFG size distributions obtained with 3D CLSM contain no secondary population around 1 μm, in contrast to laser diffraction measurements. This suggests that the bimodal MFG distribution obtained by laser diffraction can be an artifact of the built-in fitting algorithm, instead of an actual feature of human milk. This work demonstrates that care should be taken when interpreting size distributions of MFGs measured with laser diffraction and that 3D CLSM is an accurate alternative for measuring size distributions in lactation and dairy research.
人乳中的乳脂肪球（MFGs）为母乳喂养的婴儿提供能量并支持婴儿发育。准确测量MFG的大小分布对于更好地理解MFG的功能和来源，以及MFG大小对乳汁成分分析方法的影响至关重要。然而，常用的激光衍射系统从未针对人乳中的大小分布测量进行过全面验证。在此，我们介绍一种使用三维共聚焦激光扫描显微镜（CLSM）结合MFG荧光标记来测定人乳中乳脂肪球大小分布的新方法。我们使用聚苯乙烯微球尺寸标准对三维CLSM与激光衍射法（马尔文帕纳科公司的Mastersizer 2000）进行验证和比较。接下来，我们应用这两种方法评估人乳中的MFG大小分布。我们表明，与激光衍射法相比，三维CLSM可用于获得500纳米至10微米之间更准确的大小分布。重要的是，与激光衍射测量结果不同，通过三维CLSM获得的MFG大小分布在1微米左右没有二次峰。这表明通过激光衍射获得的双峰MFG分布可能是内置拟合算法的假象，而非人乳的实际特征。这项工作表明，在解释通过激光衍射测量的MFG大小分布时应谨慎，并且三维CLSM是泌乳和乳制品研究中测量大小分布的准确替代方法。
