Improvements in the extraction of milk phospholipids from beta-serum using ultrasound prior to tertiary amine extraction

Abstract

We report improvements in the extraction of milk phospholipids (MPLs) from beta-serum, a dairy byproduct, by applying ultrasound prior to a tertiary amine extraction. Three acoustic intensities (15.53 ± 1.20, 31.76 ± 2.46, or 44.56 ± 3.47 W cm−2) were applied for 4 min before the amine extraction (N,N-dimethylcyclohexylamine, CyNMe2). The extracted lipids were fractionated by solid phase-microextraction, and the recovered MPLs were quantified by HPLC-CAD. An acoustic intensity of 44.56 ± 3.47 W cm−2 followed by CyNMe2 extraction (12/1, solvent to ratio) yielded 69.67 ± 3.45% of MPLs, while only 7.57 ± 0.59% were recovered without ultrasound. The fraction of MPLs was made of phosphatidylinositol (32%), phosphatidylethanolamine (30%), and sphingomyelin (37%). Scanning electron images and particle size revealed significant disruption of the complex arrangement between membrane proteins and MPLs, which may help to release the MPLs into the aqueous medium.