Extraction of wheat germ oil by supercritical CO2: Oil and defatted cake characterization

In this paper the working conditions for the extraction of wheat germ oil in a supercritical CO₂ pilot plant of 1-L-extraction capacity were studied. The best conditions were: pressure, 38 MPa; temperature, 55°C; wheat germ particle size, about 0.35 mm; CO₂ flow rate, 1.5 L min⁻¹. These conditions gave yields of about 92% of total oil after 3 h of processing. The obtained oils and the partially defatted cake were investigated with regard to their FA, tocol (tocopherol and tocotrienol), carotenoid, and sterol compositions and to their quality characteristics (FFA, PV, para-anisidine value, and color of the by product). Moreover, the oil quality was evaluated in relation to the progress of the supercritical extraction.