Tg polar

Fatty acids were determined by gas chromatography with flame ionization detector (GC-FID) using a chromatograph (Thermo Scientific TRACE 1300, Milano, Italy) and a fused silica capillary column (TG-POLAR, Thermo Scientific, 60 m, 0.25 mm and 0.2 μm). Hydrogen was used as carrier gas at a flow rate of 3 mL/min. To perform the analysis, 50 mg of oil was mixed with 4 mL of hexane, to which 150 μL of KOH solution (2 M in methanol) was added. The mixture was shaken for 10 min at ambient conditions and the upper layer was transferred to the GC vials. A volume of 1 μL was injected into the column through a split injector (1 of 10 μL) heated at 260 °C. Once injected, the sample passed through a column with the following temperature gradient: 50 °C for 1 min, 175 °C at a rate of 5 °C/min and 250 °C at 1 °C/min. The fatty acids methyl esters (FAME) of the samples were identified by comparing their retention times with standards (SUPELCO FAMEs Mix GLC-30; Sigma Aldrich, Milano, Italy). The determination was performed by measuring the area, expressed as percentage of normalized areas of the total fatty acids.

Fatty acid methyl esters (FAMEs) were prepared by direct acid-catalysed transesterification of dried samples (WF, MP, and breads) and were analysed by a Trace 1300 gas chromatograph (Thermo Fisher Scientific, Waltham, MA USA) equipped with a column TG-Polar, 60 m length × 0.25 mm i.d., 0.2 μm film thickness (Thermo Fisher Scientific). Details about derivatisation procedure and chromatographic conditions have previously been reported by Osimani et al. [33 ].