Soybean oil refinery is one oil refining method in oil processing. Nowadays a growing number of mini soybean oil refinery plants have been built as farmer-owned cooperatives or on farms to process locally produced soybeans or other oilseeds. These soybean oil refinery plants recently developed extrusion-expelling (E-E) technology now marketed by Insta Pro International, Triple “F,” Inc. (Des Moines, IA). E-E uses a dry auto genous extruder in which heat is generated by friction prior to screw pressing.
It is very convenient and economical to have local suppliers of soybean meal for livestock feeders. Apart from that, there is growing interest in natural, organic, and identity-preserved nongeneti-cally modified or genetically enhanced soybean products (modified by either transgenic means or traditional breeding). Various types of GE soybeans are being developed to improve nutritional and functional properties of oil, such as beans containing a higher percentage of oleate or lower percentage of linolenate or saturates compared to commodity product, or beans containing no lipoxygenase.
Oils from these seeds may command higher prices than commodity oil. These market opportunities cannot be easily served by today’s large solvent extraction plants (typically 3,000 mt/d), but the small E-E plants are eager to adopt such strategies to capture greater returns, provided little capital investment is required and the process technology is relatively simple.