Extraction of phospholipids from beta‐serum using switchable solvents and solid‐phase extraction

Abstract We report the extraction of milk phospholipids (MPLs) from beta‐serum with a tertiary amine (N‐N dimethylcyclohexylamine, CyNMe2). The extraction time (3, 10, and 18 h), temperature (25, 40, and 60°C), and sample‐to‐solvent ratio (1/3, 1/10, and 1/18 v/v) were evaluated according to a factorial design. The extracted lipids were fractionated with solid‐phase extraction and quantified by HPLC‐CAD. Extraction conducted at 60°C yielded values of 14.86 ± 2.95%, 69.79 ± 3.19%, 79.39 ± 5.55% after 3, 10, and 18 h and a ratio of 1/18 (w/w). Microstructure images showed significant damage to the solid matrix that released the inner MPLs into the aqueous medium. The highest extraction yields of MPLs (79.39 ± 5.55%) were obtained after 18 h of extraction at 60°C and a sample‐to‐solvent ratio of 18 (w/w). The recovered fraction was made of phosphatidylinositol (~41%), phosphatidylserine (~6%), phosphatidylethanolamine (~34%), phosphatidylcholine (~9%), and sphingomyelin (~8%). This work outlines different extraction conditions for recovering MPLs from beta‐serum, a dairy byproduct.