Dairy phospholipids (PL) is of interest due to their health benefits and functional properties. Solvent fractionation of PL has not been commonly used in the dairy industry to fractionate milk fat to obtain or concentrate the PL. The total lipid extracted from the β stream, a waste by‐product of dairy processing, was used in this study to investigate suitable solvent and conditions to separate the neutral lipid from PL. A fixed lipid solvent ratio (1:10 g/v) was used at various fractionation temperatures (−20, 2, 15, 23, 40, and 60 °C) depending on the solvents. The use of acetone at 23 °C, not at the lower temperatures, led to a dairy lecithin product with high PL content, such as 71.5%. The more aqueous ethanol, i.e. at 70% concentration compared to 95%, was able to preferentially extract PL to form products with up to 74.7% PL, but the PL yield was much lower (26.3%) compared to acetone precipitation (97.9%). The enrichment of branch chain fatty acids proved to be very challenging due to the overlapping melting points with other fatty acids. The composition of the major fatty acids of polar and neutral lipids also showed interesting patterns that may indicate different nutritional and oxidative properties of the fractionated products.

中文翻译：

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乳制品副产物磷脂和支链脂肪酸的工业升级方法开发

乳磷脂（PL）由于其健康益处和功能特性而备受关注。PL的溶剂分馏在乳品行业中并不普遍用于分馏乳脂以获得或浓缩PL。本研究使用从β流中提取的总脂质（乳制品加工的副产品）研究合适的溶剂和条件，以从PL中分离中性脂质。根据溶剂的不同，在各种分馏温度（-20、2、15、23、40和60℃）下使用固定的脂质溶剂比率（1:10 g / v）。在23°C（而不是在较低的温度）下使用丙酮导致乳化卵磷脂产品的PL含量较高，如71.5％。乙醇含量更高（即与95％的浓度相比，浓度为70％）能够优先提取PL，从而形成PL含量高达74.7％的产品，但是与丙酮沉淀（97.9％）相比，PL的收率要低得多（26.3％）。由于与其他脂肪酸的熔点重叠，因此支链脂肪酸的富集被证明是非常具有挑战性的。极性和中性脂质的主要脂肪酸组成也显示出有趣的模式，这可能表明分馏产物的营养和氧化特性不同。