The flax seeds were dried on a metal tray at 50 °C for one hour as pretreatment and stored at 4 °C for 24 h in low-density polyethylene bags. The cold extraction of oil from flax seeds was carried out using a Komet CA 59 G single screw expeller (IBG Monforts Oekotec,Germany), at a speed of 24 RPM and with an 8mm diameter nozzle.Before the extraction, the cake outlet nozzle was preheated to 60 °C for 30 min to prevent its obstruction. Some linseed oil was passed and discarded to obtain a continuous flow during the extraction. The effective extraction temperature of the oil was 43.7 °C. Afterwards, centrifugation (Centra CL2, Thermo Fisher Scientific, USA) was performed at 1421g for 15 min to remove impurities from the oil. Linseed oil was stored at 4 °C under nitrogen atmosphere in the dark until enrichment and analysis.