Michalski M C, Briard V, Michel F, Tasson F, Poulain P
INRA-UMR 1253, Science et Technologie du Lait et de l'Oeuf Agrocampus 65, rue de Saint-Brieuc, 35042 Rennes Cedex, France.
J Dairy Sci. 2005 Jun;88(6):1927-40. doi: 10.3168/jds.S0022-0302(05)72868-X.
Only a few results are available on the size of human milk fat globules (MFG), despite its significance regarding fat digestion in the infant, and no data are available at <24 h postpartum (PP). We measured the MFG size distribution in colostrum and transitional human milk in comparison with fat globules of mature milk and infant formula. Colostrum and transitional milk samples from 18 mothers were collected regularly during 4 d PP and compared with mature milk samples of 17 different mothers and 4 infant formulas. The size distribution was measured by laser light scattering. For further characterization, the zeta-potential of some mature MFG was measured by laser Doppler electrophoresis. The MFG diameter decreased sigmoidally in the first days. At <12 h PP, the mode diameter was 8.9 +/- 1.0 microm vs 2.8 +/-0.3 microm at 96 h PP. Thus, the surface area of MFG increased from 1.1 +/-0.3 to 5.4 +/-0.7 m2/g between colostrum and transitional milk. In mature milk, the MFG diameter was 4 microm on average and increased with advancing lactation, whereas the droplets in infant formula measured 0.4 microm. The zeta potential of mature MFG was -7.8 +/- 0.1 mV. The fat globules are larger in early colostrum than in transitional and mature human milk and in contrast with the small-sized fat droplets in infant formula. Human MFG also have a low negative surface charge compared with bovine globules. These structural differences can be of nutritional significance for the infant.
尽管人乳脂肪球（MFG）的大小对于婴儿脂肪消化具有重要意义，但目前关于其大小的研究结果较少，且产后<24小时（PP）的数据尚无报道。我们测量了初乳和过渡乳中MFG的大小分布，并与成熟乳和婴儿配方奶粉中的脂肪球进行了比较。在产后4天内定期收集了18位母亲的初乳和过渡乳样本，并与17位不同母亲的成熟乳样本以及4种婴儿配方奶粉进行了比较。通过激光散射测量大小分布。为了进一步表征，通过激光多普勒电泳测量了一些成熟MFG的zeta电位。MFG直径在最初几天呈S形下降。产后<12小时时，众数直径为8.9±1.0微米，而产后96小时时为2.8±0.3微米。因此，初乳和过渡乳之间MFG的表面积从1.1±0.3增加到5.4±0.7平方米/克。在成熟乳中，MFG平均直径为4微米，并随着哺乳期的推进而增加，而婴儿配方奶粉中的液滴直径为0.4微米。成熟MFG的zeta电位为-7.8±0.1毫伏。早期初乳中的脂肪球比过渡乳和成熟人乳中的脂肪球大，与婴儿配方奶粉中的小尺寸脂肪滴形成对比。与人乳脂肪球相比，人MFG的表面负电荷也较低。这些结构差异可能对婴儿具有营养意义。
