Ingredient and Dairy Technology, Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg, Denmark.
Ingredient and Dairy Technology, Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg, Denmark; Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
Food Res Int. 2024 Sep;192:114680. doi: 10.1016/j.foodres.2024.114680. Epub 2024 Jul 2.
Driven by the acknowledged health and functional properties of milk fat globules (MFGs), there is a growing interest to develop gentle methodologies for separation of fat from milk. In this study, separation of fat from raw milk and fractionation in streams containing MFGs of different size was achieved using a series of two silicon carbide ceramic membranes. A first step consisting of a 1.4 µm membrane aimed to concentrate the bulk of the fat, i.e. the larger MFGs (D[4,3] ∼ 4 µm) followed by a 0.5 µm fractionation aimed to concentrate the residual milk fat in the permeate, i.e. fraction with the smaller MFGs (D[4,3] ∼ 1.8-2.4 µm. The fat separation performance showed a yield of 92 % for the 1.4 µm membrane and 97 % for the 0.5 µm membrane. Both fat enriched retentates showed, by the confocal laser scanning microscopy, intact MFGs with limited damage in the MFG membrane. The fatty acid profile analysis and SAXS showed minor differences in fat acid composition and the crystallization behavior was related to differences in the fat content. The 0.5 µm permeate containing the smallest MFGs however showed larger aggregates and a trinomial particle size distribution, due to probably pore pressure induced coalescences. The series of silicon carbide membranes showed potential to concentrate some of MFGM proteins such as Periodic Schiff base 3/4 and cluster of differentiation 36 especially in the 0.5 µm retentates. A shift in casein to whey protein ratio from 80:20 (milk) to 50:50 was obtained in the final 0.5 µm permeate, which opens new opportunities for product development.
受乳脂肪球（MFGs）公认的健康和功能特性的驱动，人们越来越有兴趣开发温和的方法从牛奶中分离脂肪。在这项研究中，使用一系列两种碳化硅陶瓷膜从生牛乳中分离脂肪并在含有不同大小 MFGs 的料流中进行分级。第一步是使用 1.4 µm 膜浓缩大部分脂肪，即较大的 MFGs（D[4,3]∼4 µm），然后使用 0.5 µm 膜进行分级，以浓缩残留的牛奶脂肪在渗透物中，即较小的 MFGs（D[4,3]∼1.8-2.4 µm）的级分。脂肪分离性能显示 1.4 µm 膜的产率为 92%，0.5 µm 膜的产率为 97%。通过共焦激光扫描显微镜观察，两种富含脂肪的截留物均显示出完整的 MFGs，MFG 膜的损伤有限。脂肪酸组成分析和 SAXS 表明脂肪酸组成存在微小差异，结晶行为与脂肪含量的差异有关。然而，含有最小 MFGs 的 0.5 µm 渗透物由于可能的孔压诱导聚结，显示出更大的聚集体和三项粒径分布。碳化硅膜系列具有浓缩一些 MFGM 蛋白的潜力，例如周期性 Schiff 碱 3/4 和分化簇 36，特别是在 0.5 µm 的截留物中。最终 0.5 µm 渗透物中酪蛋白与乳清蛋白的比例从 80:20（牛奶）变为 50:50，为产品开发开辟了新的机会。
