Location: Bioproducts ResearchTitle: Toxin content of commercial castor cultivars) Author
Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2014
Publication Date: 7/10/2014
Publication URL: dx.doi.org/10.1007/s11746-014-2505-3
Citation: Mckeon, T.A., Auld, D., Brandon, D.L., Leviatov, S., He, X. 2014. Toxin content of commercial castor cultivars. Journal of the American Oil Chemists' Society. DOI: 10.1007/s11746-014-2505-3. Interpretive Summary: While the US still imports 6-7 billion barrels of oil annually, the development of crops that can replace petroleum imports will be beneficial to the balance of trade. Most such crops are proposed for fuel replacements, such as biodiesel and ethanol; yet 30% of petroleum imports are used in producing detergents, lubricants, polymers, plastics and solvents. Castor oil is already used for some of these products, but production of the oil is limited and it is all imported. The presence of ricin in the seed is a major impediment to re-introducing the castor as a crop, even though it is well-suited to grow on marginal and set-aside land, and under ideal conditions can produce the equivalent of 6 barrels of oil per acre. This study evaluates the ricin content of several commercial cultivars of castor and has established parameters for identifying potentially low ricin castor selections for breeding. A low or no ricin castor would provide a profitable crop requiring low agricultural input and help to reduce the need for imported petroleum.
Technical Abstract: The castor plant Ricinus communis L. is the source of castor oil which has numerous uses and is a key chemical feedstock for an array of products from polymers to cosmetics. Although castor was once widely grown throughout the world, the presence of the toxic protein ricin has deterred the re-introduction of this useful crop. In order to develop a low ricin or no-ricin castor crop, a robust, accurate method for screening castor seed for ricin content is essential. We have screened a collection of castor seeds including commercial varieties and present the data here. Although the average content derived by extracting several seeds provided a fair representation of the ricin content for a given selection, there was enough seed-to-seed variation to justify determining the ricin content of individual seeds. Ricin levels observed ranged from 1.16% to 6.25% by weight.