Extraction and Refining

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top 1000How Baking Works
How Baking Works

By Paula Figoni

Published 2003

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Oils are extracted from soybeans and other oilseeds, nuts, and fruit primarily through the use of solvents. Hexane is the solvent of choice, since it is very efficient, and once the oil is extracted, the hexane can be separated out and reused. Because hexane is highly volatile, traces of it are easily removed by heating the oil.

Once the “crude” oil is extracted, it is refined in two main steps. The first refining step, degumming, is when naturally present emulsifiers, primarily lecithin, are physically removed by centrifuging (spinning) the oil with water. The emulsifiers are spun out with the water, and the lecithin can be purified and sold separately. Soybean oil, being high in emulsifiers, is in fact the main commercial source of lecithin.