11 - Oil Recovery from Soybeans

Abstract

Soybeans (SB) in Asia and sesame seed and olives in the Middle East were the earliest sources of vegetable oils for food, cosmetics, lubricants, and chemicals. Soybean is a very important crop to the economies of the United States and Brazil as a source of edible oil and high-protein meal for supplementing animal diets. No other crop rivals soybeans for high-quality feed protein and only palms rival soybeans as a world source of edible oil. Despite the wide diversity of today's sources of vegetable oils, all recovery processes, whether for soybeans or other oilseeds, are designed to obtain triglycerides in high yield and purity and to produce co-products (usually high in protein content) of maximum value. Oilseeds, including soybeans, are processed by one or more of three types of processes—hard screw pressing, prepress solvent extraction, or direct solvent extraction. In the case of soybeans, the vast majority (>97%) are processed today by direct solvent extraction and only modest amounts by various forms of hard screw pressing (~3%). Only in one instance soybeans being crushed by prepress solvent extraction has been observed and that plant normally crushed sunflower seed—the amount of oil in soybeans does not warrant this type of processing that is used for higher oil-containing seeds, such as sunflower, peanuts, safflower, and canola.