Physical and Chemical Processes to Enhance Oil Recovery from Condensed Corn Distillers Solubles

Oil recovery from corn fermentation co-products can provide feedstock for biodiesel production. The effects of physical and chemical processes on oil recovery from condensed corn distillers solubles (CCDS) were investigated. Heating disrupted physical interactions in the CCDS and increased oil recovery by 2.5-fold when temperature was increased from 25 to 59 A degrees C. Oil recovery at acidic pH conditions was significantly greater than at alkaline pH. Oil recovery at alkaline pH was increased by heating and addition of the reducing agent, sodium metabisulfite. Oil extraction using polar solvents isopropanol and butanol achieved greater than 80% oil recovery. When oil was co-extracted with zein using hexane and ethanol as co-solvents, the greatest total oil recovery was achieved, 89%. Churning CCDS at pH 3.5, 50 A degrees C for 3 h achieved up to 80% oil recovery. This study provides data for designing further effective methods for oil separation from corn ethanol co-products.