The castor seed (ricinus communis) is a seed of large plant, castor oil plant, grown throughout the tropics. This plant is believed to be a native of Africa new Encyclopedia particularly in Nigeria where all the species are found. Today Asia is the largest area of castor seeds and castor oil, and India is the largest producer of castor seeds and accounts for over 80% of the global production, followed by China, while USA and UK are major buyers. In India it is a kharif crop, sowing in July-August and arrivals from December onwards till March. Gujarat is the chief producing state, having a share of 86% of domestic production, followed by Andhra Pradesh and Rajasthan.
Castor seed is the source of castor oil, and the castor planting is grown commercially for pharmaceutical and industrial uses of its oil. The seeds contain between 40% and 60% oil that is rich intriglycerides, mainly ricinolein. The seed also contains ricin, a water-soluble toxin, which is also present in lower concentrations throughout the plant.
2. Castor Seed Primary Process: Hulling and Shelling
The castor seeds are dehulled after harvesting. Commercial processing of castor seed is mostly based on the dry process techniques and many of the operations particularly shelling have been done by shelling machine, and good design and operation will yield highly split grains. The husking of castor seeds has been described as the primary refining process by which the texture and culinary properties of such grains are improved by the removal of fibrous seed coats defined husking or shelling as the process of removing the fibrous colored hulls of legumes seeds as traditionally practiced as primary process in Asia countries where such legumes are grown in large quantities and consumed in a variety of food preparations. It also helps in promoting ease of digestion and effective utilization of nutrient by the body tissue. It has been reported that hulling may efficiently shorten the cooking period of grains.
3. Shelled Castor Seed Deep Processing: Castor Oil and Derivatives Market Analysis and Segment Forecasts
Shelled castor seeds are a rich source of oil which can be extracted by milling, boiling, pressing or solvent extraction. The first stage of castor seed oil extraction is pre-pressing, normally using a high pressure continuous screw press – called the expeller. Extracted oil is filtered, and the material removed from the oil is fed back into the stream along with fresh material. Material finally discharged from the press, called castor cake, contains 8-10% oil. It is crushed into a coarse meal, and subjected to solvent extraction with heptane to extract further oil. Apart from medical applications, the oil has long been used as an inexpensive fuel for oil lamps. Because of its high proportion of the fatty acid ricinoleic acid, today it is a valued industrial raw material for lubricants, paints, coats, cosmetic products and many more.
Global castor oil and derivatives market demand is rising. Growing demand for biodegradable and sustainable products on account of industry shift towards reducing reliance on petrochemicals is expected to remain a key driving factor for global castor oil and derivatives market. Volatile petrochemical derived product prices on account of supply-demand imbalances have raised concerns for global chemical industry which has prompted this shift towards bio-based chemicals. Regulatory support is also expected to have a positive influence on the market owing to regulation for controlling environmental hazards linked with petrochemicals and conventional sources acting in favour of castor oil and derivatives market. Growth of major end-use industries including automotive, cosmetics, pharmaceuticals and textiles is expected to further fuel the demand for castor oil and its derivatives.
4. Another Affiliate Products of Castor Seed: Castor Meal
Two main by-products are generated in the castor oil production process: the capsule husks, produced when the seeds are separated from the fruits, and the meal, produced when the oil is extracted from the seed. Assuming that the seed weight corresponds to 62% of the fruit weight, and the efficiency of oil extraction is 47%, the production of 1 ton of castor oil results in 1.31 tons of husks and 1.13 ton of meal. Annual castor seed production in the world is around 1.2 × 103 ton; therefore, 741 × 103 ton of castor husks and 642 × 103 ton of castor meal are produced each year.
Castor meal is one of the most versatile natural manures. It is truly an organic manure which enhances the fertility of the soil without causing any damage or decay. It is enriched with the three big elements vital and conducive to the proper growth of crops - Nitrogen, Phosphorus and Potassium. It also has traces of nutrients like Manganese, Zinc and Copper, thus making it a balanced fertiliser. Moreover, it helps to neutralise the detrimental effects of chemical fertilisers. Apart from their contribution to Nutrients , they have a number of benefits in agriculture, which none of the synthetic fertilizers or pesticides can offer. They bring in the wonderful molecules that nature has designed to help the plants flourish naturally. They provide slow and steady nourishment, stimulation , protection from soil nematodes and insects, improve yields, and quality of product like taste, flavour, amino acid composition etc.
Asian shelled castor seed and its extenders such as castor seed oil, castor seed oil derivatives, castor meal and so on, have high market value, and the market share of these is increasing along with the development of economic, for example, surge in demand for organic and natural cosmetic products are expected to create lucrative opportunities for the global castor oil and derivative market. And it also drives the export, for example, South Korea is large buyer from India and buys more than 90% of total castor seed meals exported from India. At the same time, developing the castor varieties and planting technology, and improving the castor seed processing equipment and methods, are necessary for the market demand.