Properties and processing of corn oils obtained by extraction with supercritical carbon dioxide

Crude oils were extracted from wet- and dry-milled corn germs with supercritical carbon dioxide (SC-CO2) at 50–90 C and 8,000–12,000 psi and were characterized for color, free fatty acids, phosphorus, refining loss, unsaponifiable matter, tocopherol and iron content. They were compared with commercial products. Extraction of wetmilled germ with SC-CO2 has some advantages over the conventional prepress solvent method commonly used in the industry. For example, SC-CO2 extraction of wet-milled germ at 50 C and 8,000 psi yields crude oil with a lower refining loss and a lighter color. After laboratory processing, a light-colored, bland salad oil is obtained. Crude, refined, bleached and deodorized oils from SC-CO2-extracted dry-milled germ appear equivalent to those obtained by expeller pressing.