The soy bean is the bean of all beans, as it were. In the past 50 years, it has become the most important oil seed fruit in the world and now constitutes about a third of all oleiferous plants cultivated. The main growing countries apart from the USA include China, Brazil and Argentina. Soy oil is rich in unsaturated fatty acids such as linoleic acid and is consequently also playing a growing role in healthconscious eating.
Phosphatides have to be removed in order to produce edible soy oil. Separators from GEA Westfalia Separator Group perform key tasks in water degumming and neutralization. They are also used in washing the neutralized oil.
After the soy oil has been extracted from the soy beans using hexane, water is added for so-called water degumming. The hydratable phosphatides swell up and can now be separated from the oil by a separator.
The separated gums are dried and traded as high-value lecithin.
Chemical refining follows on from water degumming. Acid and caustic are used to neutralize the free fatty acids and even nonhydratable gums can be reliably removed. Separators from GEA Westfalia Separator Group separate the soapstock which results, so the cleaned oil now only needs washing.
In this process, the wash water in turn is separated by a separator and treated with the soapstock by a strong acid to obtain fatty acid. The neutral oil is then bleached and deodorized.