Publication no. C-2000-1010-07R |  VIEW ARTICLE

Solvent Extraction of Zein from Dry-Milled Corn.

Rishi Shukla (1), Munir Cheryan (1,2), and Richard E. DeVor (3). (1) Agricultural Bioprocess Laboratory, University of Illinois at Urbana-Champaign, 1302 West Pennsylvania Avenue, Urbana 61801. (2) Corresponding author. Phone: 217-333-9332. Fax: 217-333-9592. E-mail: <mcheryan@uiuc.edu> (3) Department of Mechanical and Industrial Engineering, University of Illinois, Urbana. Cereal Chem. 77(6):724-730. Accepted August 15, 2000. Copyright 2000 American Association of Cereal Chemists, Inc.

Batch extraction of zein from dry-milled whole corn with ethanol was optimum with 70% ethanol in water, an extraction time of 30-40 min, and temperature of 50°C. High yields (60% of the zein in corn) and high zein contents in the extracted solids (50%) were obtained at a solvent-to-solids ratio of 8 mL of 70% ethanol/g of corn. However, zein concentration in the extract was higher at lower ratios. Multiple extraction of the same corn with fresh ethanol resulted in a yield of 85% after four extractions, whereas multiple extractions of fresh corn with the same ethanol resulted in high (15 g/L) zein concentration in the extract. Optimum conditions for batch extraction of zein were 45°C, with 68% ethanol at a solvent-to-solids ratio of 7.8 mL/g for an extraction time of 55 min. Column extractions were also best at 50°C and 70% ethanol; a solvent ratio of 1 mL/g resulted in high zein concentrations in the extract (17 g/L) but yields were low (20%).