Comparative of Physico-Chemical Properties of Wheat Germ Oil Extracted with Cold Press and Supercritical CO2 Extraction

Abstract

<em>In this study, moisture content, free fatty acids, peroxide, iodine value, unsaponifiable matter, saponification value, fatty acid composition and tocopherol contents of wheat germ oil obtained by SC-CO₂ extraction and cold press technology were investigated. Moisture, free fatty acid (FFA), peroxide value, iodine value, unsaponifiable matter and saponification value of cold press and supercritical CO₂ extraction method oils were established as 0.097% and 13.32, 0.84% and 5.9%, 8.9 meq O₂/kg and 15.8, 132 and 128, 6.5 g/kg and 8.04 and 197 and 182mg KOH/g, respectively. Major fatty acids of samples were determined as palmitic, oleic, and linoleic acids. Campesterol and β-stosterols of wheat germ oils obtained by the cold press and supercritical CO₂ extraction are the major sterols. The germ oil extracted by both methods contained 24.19% and 23.44 % campesterol and 60.98% and 61.56% β-stosterol, respectively. While germ oil obtained supercritical CO₂ extraction contains 50.60% α-tocopherol and 49.39% β-tocopherol, the oil obtained by cold press contained 73.12% α-tocopherol and 26.83% β-tocopherol. Supercritical CO₂ extraction is conducted for the process that must be decided whether the pilot or industrial scale. Supercritical CO₂ extraction that high oil yield is very high investment costs.</em>