What is in this article?:
- Castor beans are back in California as a possible source crop for making biofuels.
- Castor's main toxic protein, ricin, is so potent that a single milligram is sufficient to kill an adult.
- Castor oil is essential to the global specialty chemical industry because it is the only commercial source of hydroxylated fatty acids.
Australian Nic George, left, is a UC associate specialist,who is working on oilseed research with UC Davis Cooperative Extension biofuels guru Steve Kaffka, right. They are standing beside a castor trial.
Major castor role pending
Texas researchers are taking another look at castor because of its high seed oil content for potential use in the production of specialty chemicals, biodiesel, and RFS2 renewable fuel.
A group of Texas A&M and Texas Tech researchers have been working together on a castor variety that greatly reduces risk and still offers value in production.
“With castor seed producing as much as 50 percent oil and its ability to grow productively on marginal land, it represents a crop that could address a growing demand for castor oil. India virtually controls the global market now, and there is potential for domestic production,” reports Calvin Trostle, associate professor and research scientist at Texas A&M AgriLife in Lubbock.
“Castor production will play a major role for many years to come,” agrees Dick Auld, oilseed crop specialist and research scientist at Texas Tech University.
Last year at a Texas crop tour, Travis Miller, AgriLife Extension program leader and associate department head for the department of soil and crop sciences at Texas A&M University, told attendees a successful castor industry will require isolating castor seed and using a number of strategies to insure it remains only in industrial oil handling and marketing channels.
“The long term solution is to develop castor varieties that greatly reduce toxicity, and we’re well on the road to achieving this goal,” Auld explains.
A new variety known as the Brigham, so named after the advancement of castor research by R.D. Brigham of the USDA Research Center in Lubbock, has provided promising results, effectively reducing ricin toxicity by 70 percent to 90 percent. A semi-dwarf variety, Brigham also allows for mechanized commercial production. Bingham is from Castagra, a Canadian bioproducts company.
“And this is just a start. We are working to further reduce ricin levels in an effort to make the plant safe. We would like to reduce ricin levels to 3 percent,” Auld adds. Conventional breeding to rid castor of lethal ricin and troublesome allergens hasn't solved the problem. However, using biotechnology, scientists have been able to advance the breeding of ricin-reduced castor.
“Castor is certainly a crop that requires careful management, such as proper isolation from food crops and good hygiene practices,” Auld concedes.
Trostle adds that researchers are recommending stringent management and control measures, such as dedicating combines to castor-only applications, taking safeguard in transportation and storage of castor seed to eliminate contamination.
“Certainly we need to proceed with utmost care and careful consideration of every safety issue. No one wants to proceed without making certain each issue has been adequately addressed,” he says.
Currently castor trials continue on test plots in that region and also in the Lubbock area, and some testing of Brigham castor have been staged in the Coastal Bend and in southeast Texas.