Gas-Assisted Mechanical Expression of Oilseeds
Present-day technologies for the production of vegetable oils include hydraulic pressing, screw pressing, and solvent extraction with hexane. Of these methods, solvent extraction has the highest yield, but results in a lower quality of the oil. Pressing methods produce higher quality but lower yields. Today, consumers are becoming more aware of the presence of potentially hazardous chemicals in foodstuff. It is therefore necessary to prevent the use of organic solvents in the production of vegetable oils for consumption. Two potential alternatives for oil production are extraction with supercritical carbon dioxide (SCE) and a novel process called gas-assisted mechanical expression (GAME). In the SCE process, the oil is dissolved in CO2 and thereby extracted from the plant material. However, the solubility is limited to only a few weight percent at reasonable conditions.