Quality evaluation of flaxseed oil obtained by different extraction techniques

Quality of flaxseed oil obtained by supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE) was evaluated and compared with that of the conventional solvent extraction (SE). The oil yield obtained by SFE, ASE and SE was 36.49, 41.90 and 42.40 g/100 g, respectively. There were no significant differences between ASE and SE oils in their physicochemical properties and fatty acid profiles; however SFE oil showed significantly lower melting point (MP), peroxide value (PV) and saturated fatty acids and higher iodine value (IV) and polyunsaturated fatty acids (PUFAs). Furthermore, SFE oil showed significantly higher phenolic acid content (47.58 mu g/g) as compared to 20.88 mu g/g and 15.69 mu g/g in ASE and SE oils, respectively. The main flaxseed lignan; secoisolariciresinol diglycoside (SDG) was found only in the SFE oil (32.28 mu g/g). Oils did not differ significantly in their tocopherol contents which ranged from 34.47 to 34.88 mg/g. These results advocate the use of SFE for flaxseed oil extraction. (C) 2013 Elsevier Ltd. All rights reserved.