2.8.4. Preparation and GC-FID Analysis of Sterols Compounds

The sterol identification and quantification were determined according to the official European analysis methods [54,55]. The compounds were extracted and silylated previously to the chromatographic separation and analysis on a GC–FID Varian 450 (Torino, Italy), with a Phenomenex capillary column (30 m × 0.25 mm internal diameter × 0.25 µL film thickness) (Torrance, CA, USA). The oven temperature was programmed from 250 °C to 280 °C, using helium (Gasin, Porto, Portugal) as the carrier gas. Software SW ChemStation vD.01.00 (Santa Clara, EEUU) was used for data acquisition. Total sterol content was expressed in mg/kg, and sterol profile as a percentage (%).