Castor bean (Ricinus communis)
An annual or perennial oilseed originating in East Africa, especially Tanzania, Kenya, Uganda, it can be found on dry waste land. The plant has a substantial tap root with many lateral branches which can reach a great depth. Annual cultivated varieties reach a height of 0.9 - 1.5m whilst natural perennial varieties can grow as tall as 6m.

The regions in which Castor may be grown as a commercial crop are restricted by lack of frost tolerant types and the need for high temperatures (optimum 20 - 25ºC, over 4.5 - 6 months) and low atmospheric humidity to achieve good yields and offers the possibility for mechanical harvesting. The average seed yield is 4500 Kg/Ha with a maximum up to 6750 Kg/Ha when irrigated. CastorPro is a group of hybrids with an extreme high oil yield. In tropical regions oil yields of >2000 Kg/ha are no exception. We can provide you with the seeds to grow these hybrids.
Castor seed (bean) is the source of Castor Oil, which has a very wide variety of uses. The Castor bean contains 50-55% oil. The oil itself contains a number of fatty acids similar to those in cooking oils, such as oleic acid, linoleic acid, stearic acid and palmitic acid. However, among vegetable oils, Castor Oil is distinguished by its high content (over 85%) of ricinoleic acid. Ricinoleic acid is the most important commercial source of hydroxy fatty acids (>160).

Castor oil's unsaturated bond, high molecular weight (298), low melting point (5ºC) and very low solidification point (-12ºC to -25ºC) make it industrially useful, most of all for the highest (300 mm/s) and most stable viscosity of any other vegetable oil. The seed coat contains ricin, a powerfull poison, which is also present in lower concentrations throughout the plant. It is the only vegetable oil which dissolves completely in alcohol. Biodiesel made from Castor Oil solidifies at -45 degrees C which is the lowest on record.
Castor Oil is sold either for pharmaceutical or industrial use. The annual production is 500.000 Ton. Specifications for pharmaceutical use can be found in the European Pharmocoepia. The industrial type may be divided into ‘first’, ‘second’ and ‘third’ quality. Only pressed Castor Oil, extracted without solvents, can be called ‘first quality’. This oil, produced in Europe, is virtually colorless and has very low acidity. ‘Second’ and ‘third’ quality oil are commercial names, meaning that the oil has been extracted using a solvent.
Ricinoleic Acid methyl ester is the biodiesel made out of Castor Oil
The ester linkages, double bonds and hydroxyl groups in Castor Oil provide reaction sites for the preparation of many useful derivatives.
Common specifications of Castor Oil include:
- Commercial Grade/Industrial Grade Castor Oil : Commercial Castor Oil is produced by crushing steam cooked Castor seeds in expeller. Oil collected from the expeller tray is collected in settling tank is filtered for removing physical impurities. A dark yellow viscous oil in appearance with Colour: 30 Max (Y+5R), F.F.A : 2.00% Max, M.I.V: 0.50% Max.
- First Special Grade Refined Castor Oil : First Special Grade Castor Oil is produced by refining Commercial Grade Castor Oil by undergoing bleaching and filtering process. Bleaching is done using bleaching earth and activated carbon, which helps to reduce colour, F.F.A. and Moisture content. Light yellow viscous oil in appearance with Colour Max: 2.2 Yellow & 0.3 (1"Cell on Lovibond Scale), F.F.A : 0.80% Max, M.I.V.: 0.25% Max.
- Pale Pressed Grade Refined Castor Oil : Pale Pressed Castor Oil, a premium product in Castor Oil category is produced from the first pressing of the Castor seed. A Pale Yellow viscous liquid in appearance and free from suspended matter, light in colour and low in acidity with Colour Max: 10 Yellow & 1.0 Red ( 5 ¼" Cell on lovibond Scale), F.F.A : 0.50% Max, M.I.V.: 0.20% Max.
- Pharma Grade Castor Oil : Pharma Grade Castor Oil is produced by first pressing of Castor seed, without losing medicinal qualities. It is a clear, brilliant Colourless or slight yellow, viscous, from rancid odour. Produced as per USP/NF, JP, BP, EP, IP, DAB pharmacopoeia and used as emollient for pharmaceutical creams and lotions.
- Cold Pressed Castor Oil - Pharma Grade : Cold Pressed Castor Oil is a pure virgin transparent Castor Oil extracted in its natural form by pressing seeds without using steam cooking. This helps to preserve herbal and healing properties. It is considered as one of the most valuable laxatives in pharma.
- Hydrogenated Castor Oil : Hydrogenated Castor Oil (HCO), produced under controlled catalytic hydrogenation. Also known as "Castor Wax", "Opal Wax" and is a hard, brittle, tasteless, odourless and high melting solid and consists mainly of 12- Hydroxystearin. It is insoluble in most organic solvents at room temperature and compatible with ethyl cellulose, acetyate butyrate, rosin, polymethacrylate, shellac, synethtic and natural rubbers, vegetable waxes and insoluble in other waxes. HCO is available as flakes or powder which melts to a clear transparent liquid. It is a non-toxic, non-hazardous material.
- 12 Hydroxy Stearic Acid : 12 Hydroxystearic Acid (12 HSA) is an off-white, high melting solid fatty acid produced by hydrolysis of Hydrogenated Castor Oil. It is insoluble in water. 12 HSA is non-toxic & non-harzardous, partially soluble in number of organic solvents and insoluble in water. 12 HSA is used in production of lithium and calcium based lubricating greases, synthesis for complex chemicals, automotive and small appliance industries uses for hard finishing.
- Dehydrated Castor Oil : Dehydrated Castor Oil is lighter than Tung Oil. Quick drying, light colour and non-yellowing nature combined with good resistance to water and alkali makes it value in even in white finishes It can be used to improve the quality of house paints, enamels, caulks, sealants and inks. This oil also works well in clear varnishes and hard finish coatings.
- Blown Castor Oil : Blown Castor Oil is produced by oxidizing Castor Oil under thermally controlled condition and has a higher Specific Gravity and Viscosity when compared to natural oils. Blown Castor Oil is a potential replacement for phthalates and an important drying oil used in surface coatings, lubricants, adhesives, for inks and lacquers. Blown Castor Oil is available in the standard viscosity 5-10 poise, 20-25 poise, 30-35 poise 45-55 poise, 90-110 poise.
- Sulfonated Castor Oil / Turkey Red Oil : Turkey Red Oil is chemically sulphated Castor Oil. It is a liquid of varying viscosity and physical characteristics. Soluble in water and available in various grades 30%, 50%, & 70% according to the product sulfated. Mainly used as wetting and penetrating agent in textile processing. Also used for pesticide formulations, soluble cutting oil, fat liquor and paper industry.
- Ricinoleic Acid : Ricinoleic Acid (12-hydroxy-9-octadecenoic acid) is obtained by the hydrolysis of Castor Oil. It is a light colored liquid with a ricinoleic content of approximately 90%. Primary uses include, coatings, plastics, personal items, inks and cosmetics.
Toxicity
As Castor seed production presents some problems (toxicity of the seed, allergic reactions), a crop named Lesquerella was proposed as a valuable alternative source of ricinoleic acid (up to 70% in the oil) but also of lesquerolic acid, the C20 homologue of ricinoleic acid (14-hydroxy-11-eicosenoic acid).