ABSTRACT
Processing of fats and oils involves first separating oil from the oil-bearing materials and then refining the oils to an acceptable quality for consumption or final applications. Because of the divergent nature of the various oil-bearing materials, there are many deviations in the preparation steps of the oil-bearing materials prior to the extraction of oils. Once the material is properly prepared, the oil may be obtained by heat rendering, such as fish and animal fats; by me chanical pressing for high oil-containing materials such as sunflower seed, rapeseed, and olive; and by direct solvent extraction such as soybean. To further improve the productivity and yield of oil, a combination of partially pressing out the bulk of the oil and solvent extraction has been used by most of the present operations of rapeseed and sunflowerseed mills. These combined processing steps are called prepress solvent extraction. Oilseeds containing less than 30% oil, such as soybean and cottonseed, are processed largely by low shear extruder or expander and then extracted by solvent. These seeds can
TABLE12.9. Fatty Acid Composition in Large Batches of Commercial Menhaden Oil from 1977-1988.
