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The effects of diet and of strain on lipid, cholesterol and fatty acid compositions of egg yolk were studied. Two hen strains (Red Lohman—RL and White Lohman—WL) and four experimental diets with different fatty acid composition were used. No significant (P 0.05) by the experimental diets. The major effects of the diets were observed in fatty acids C16:0, C18:0, C18:1n9, C18:2n6, C20:4n6, C20:5n3 and C22:6n3. The addition of oils to the diets fed to hens allowed the production of eggs with higher n3/n6 and PUFA/SFA fatty acid ratios than the eggs from control hens. It was concluded that the amounts of saturated and unsaturated fatty acids in egg yolk could be altered by dietary manipulation.

Flaxseed (Linum usitatissimum L.) oil was obtained via subcritical n-propane fluid extraction (SubFE) under different temperatures and pressures with an average yield of 28% and its composition, purity and oxidative stability were compared to oils obtained via conventional solvent extraction methods (SEMs). When the oxidative stability was measured by differential scanning calorimetry, the oil was found to be up to 5 times more resistant to lipid oxidation as compared to the SEM oils. Direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis showed characteristic and similar TAG profiles for SubFE and SEMs oils but higher purity for the SubFE oil. The flaxseed oil content of β-tocopherol, campesterol, stigmasterol and sitosterol were quantified via GC–MS. SubFE showed to be a promising alternative to conventional SEM since SubFE provides an oil with higher purity and higher oxidation stability and with comparable levels of biologically active components.