Lipozyme

Lohmann Brown hens’ eggs were a gift from the Tronina factory. Cod liver oil (CLO) was a gift from the National Marine Fisheries Research Institute, Gdynia, Poland. Lipozyme TL IM (a silica granulated Thermomyces lanuginosus lipase preparation, 250 U/g) was a gift from the Novozymes A/S (Bagsvaerd, Denmark). Lipase B from Candida antarctica immobilized in a macroporous acrylic resin (synonym: Novozym 435, >5000 U/g), lipase B from Candida antarctica (CALB, >1800 U/g), lipase A from Candida antarctica (CALA, >500 U/g) both immobilized on resin Immobead 150, lipase from Mucor miehei (Lipozyme^®, >30 U/g), lipase from Candida cylindracea (≥2 U/mg) and lipase from Burkholderia cepacia (Amano PS IM, >500 U/g) were purchased from Sigma-Aldrich (St. Louis, MO, USA). A boron trifluoride methanol complex solution (13–15% BF₃ × MeOH) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Silica gel-coated aluminum plates (Kieselgel 60 F254, 0.2 mm) used in thin layer chromatography (TLC) and the silica gel (Kieselgel 60, 230–400 mesh) used in the column chromatography were purchased from Merck.