Castor oil was treated with concentrated sulfuric acid to obtain sulfate with good surface activity (commonly known as Turkish red oil). Castor oil can be dehydrated to obtain dry oil with double bond of yoke. A variety of products can be obtained by treating castor oil under different hydrogenation conditions, so castor oil is widely used in various industrial sectors. Castor oil is the closest to pure complex triglyceride, and only olive oil (containing about 80% oleic acid), safflower oil (containing more than 70% linoleic acid) and tung oil (containing about 85% eleostearic acid) have this characteristic.
The content of unsaponifiable matter in castor oil is less than 65438 0%. The vitamin content is low (about 0.05).
Castor seeds have high oil content. Because of the different uses of oil, the methods of extracting oil are also different. Medicinal castor oil is cold pressed by hydraulic press at a temperature not exceeding 50℃, otherwise some impurities will dissolve in the oil and cannot be used as medicine. The oil obtained by cold pressing is called castor oil 1. After the cake meal is crushed, it is squeezed or leached again to prepare No.3 castor oil (No.2) for industrial use. Castor oil extracted by direct pressing or pre-pressing with screw oil press can only be used as industrial oil.