Spence A J, Jimenez-Flores R, Qian M, Goddik L
Department of Food Science and Technology, Oregon State University, Corvallis 97330, USA.
J Dairy Sci. 2009 Jun;92(6):2373-81. doi: 10.3168/jds.2008-1534.
Milk fat globule membrane contains many complex lipids implicated in an assortment of biological processes. Microfiltration coupled with supercritical fluid extraction (SFE) has been shown to provide a method of concentrating these nutritionally valuable lipids into a novel ingredient. In the dairy industry there are several by-products that are rich in phospholipids (PL) such as buttermilk, whey, and whey cream. However, PL are present at low concentrations. To enrich PL in buttermilk powders, regular buttermilk and whey buttermilk (by-product of whey cream after making butter) were microfiltered and then treated with SFE after drying. The total fat, namely nonpolar lipids, in the powders was reduced by 38 to 55%, and phospholipids were concentrated by a factor of 5-fold. Characterization of the PL demonstrated specific molecular fatty amide combinations on the sphingosine (18:1) backbone of sphingomyelin with the greatest proportion being saturated; the most common were 16:0, 20:0, 21:0, 22:0, 23:0, and 24:0. Two unsaturated fatty amide chains, 23:1 and 24:1, were shown to be elevated in a whey cream buttermilk sample compared with the others. However, most unsaturated species were not as abundant.
乳脂肪球膜含有许多与多种生物过程相关的复杂脂质。微滤与超临界流体萃取（SFE）相结合已被证明是一种将这些具有营养价值的脂质浓缩成新型成分的方法。在乳制品行业，有几种富含磷脂（PL）的副产品，如酪乳、乳清和乳清奶油。然而，磷脂的浓度较低。为了在酪乳粉中富集磷脂，将普通酪乳和乳清酪乳（制作黄油后乳清奶油的副产品）进行微滤，然后在干燥后用超临界流体萃取处理。粉末中的总脂肪，即非极性脂质，减少了38%至55%，磷脂浓缩了5倍。对磷脂的表征表明，鞘磷脂的鞘氨醇（18:1）主链上存在特定的分子脂肪酰胺组合，其中饱和脂肪酸的比例最大；最常见的是16:0、20:0、21:0、22:0、23:0和24:0。与其他样品相比，乳清奶油酪乳样品中两条不饱和脂肪酰胺链23:1和24:1的含量有所升高。然而，大多数不饱和种类的含量并不那么丰富。
