EXTRACTION OF OILSEED MODEL SYSTEMS WITH ALCOHOLS

Alcohols have potential as extraction solvents for vegetable oils offering advantages of preferred extraction selectivity, reduced energy requirements, reduced hazards of fire and explosion, and their availability from biorenewable resources. However, control of moisture from flakes to solvent is difficult, and new approaches are required to take advantage of extraction selectivity. A laboratory extractor simulator was developed to determine extraction characteristics of soybean, cottonseed, and jojoba flakes with ethanol and isopropanol in a new process called "Sequential Extraction", which was developed to extract lipids and toxins with one solvent.;In the Sequential Extraction Process, fatty materials were extracted in the first sequence and recovered by chill separation, eliminating the need for evaporation, and polar toxins were extracted in the second sequence at a lower solvent:flake ratio and recovered by evaporation. Sequential Extraction was effective in reducing residual oil contents of cottonseed meals to less than 2% with 91% isopropanol and less than 3% with 95% ethanol. The free gossypol contents of air-desolventized meals were less than 0.045% making them useable in poultry and swine feeds. Aflatoxin contents were reduced by more than 90%, facilitating the salvage of a large portion of cottonseed meal. The quality of oil recovered in Sequential Extraction was better than hexane-extracted oil.;Jojoba wax was extractable with 91% isopropanol with about 8% jojoba wax being soluble in 91% isopropanol at 78(DEGREES)C. The extraction of wax and toxic simmondsin from jojoba was shown to be feasible with 91% isopropanol in Sequential Extraction. Simmondsin was significantly reduced (90% by estimation) during the second sequence. This low level of simmondsin may make jojoba meal useful as a protein source in livestock feeds. The quality of wax was significantly better than hexane-extracted wax.;The Sequential Extraction Process may be very useful to the oilseeds crushing industry for extracting oil or plant waxes, and polar toxic compounds in a single process with a single solvent. Improved oil quality and new market for otherwise toxic meals may result.;Soybean, cottonseed and jojoba flakes containing 7% moisture were in equilibrium with 91% isopropanol. Soybean and cottonseed flakes containing 2.25% moisture were in equilibrium with 95% ethanol. These three oilseeds had the same moisture equilibrium values despite wide differences in composition. Moisture and oil equilibriums were established faster in 91% isopropanol and 95% ethanol with cottonseed flakes than soybean flakes or jojoba prepress cake.