Production of High-Value Fatty Oils

Production of oil from commodity oilseeds (sunflower, soybeans, and rape) does not appear economically viable, because of the higher costs of high-pressure batch processes. But there can be areas in which supercritical fluid extraction can be useful especially for the extraction of high-value oils. 

These can be, for example, special gourmet oils (almond, apricot, avocado, grape seed, hazelnut, and walnut) or oils used for pharmaceutical and cosmetic applications (corn germ, wheat germ, evening primrose, and borage). If the deoiled residual can also be used for food or cosmetic applications, the economy of the process increases substantially. 

A successful implementation for a commercial application was the erection of a supercritical CO2 extraction plant for roasted sesame oil. This development of a CO2 supercritical fluid extraction process for roasted sesame seeds can serve as an example for the viable production of such special oils. Sesame seeds have a relatively low tocopherol content, but contain other very effective antioxidants that stabilize the oil on the one hand and make it very tasty on the other. Roasted premium sesame oils are very popular in Asia, particularly in Korea and Japan. 

The most important antioxidants in sesame are sesamoline and sesamine, which are well soluble in CO2 and, consequently, nearly completely present in the extracted oil. The active substance is sesamole, which is formed continuously from sesamoline during aging. 

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