In 1980, the U.S. produced 1.14 billion pounds of major fatty acid raw materials consisting mostly of triglycerides which, for most applications, must be split into glycerol and free fatty acids. Some of these raw materials include fats and oils such as castor, coconut, corn, palm, soybean and tallow. From 1983-1984, world production of selected fats and oils increased from approximately 56 million metric tons to approximately 60 million metric tons in 1984-1985. The major contributors to these figures include: soy, palm, sunflower, cottonseed, butter, and tallow.

The American fatty acid industry splits fats using the Colgate-Emery process. In this process superheated steam is sparged into the fat. The usual conditions for splitting are 485 OF and 700 psig. The entire fat splitting operation is blanketed with nitrogen. Nevertheless, polyunsaturated fats undergo significant degradation and must be extensively purified by distillation for most uses. Castor oil contains ricinoleic acid, a hydroxylated fatty acid, at about the 90% level. The splitting of castor oil by a heat process is very difficult due to by-product formation. Finally, the Colgate-Emery process is very energy intensive, using about 340 Btu of energy per pound of oil split.

An efficient and inexpensive method of rapidly hydrolyzing oleaginous materials of all types into their constituent fatty acids and glycerol has been developed. This method uses a naturally immobilized lipase catalyst created from seeds. Hydrolysis may be conducted in organic solvent at room temperature to yield a colorless, nonoxidized material. The fatty acid is produced as the free acid, rather than the acid salt, and may be removed from the lipase using organic solvent washes. Yields greater than 97% can be obtained.

The process described in the patent application operates near room temperature. In the time required for complete splitting (approximately 24 hours) very little oxidation and by-product formation occurs. The lipase catalyst is prepared (activated) by grinding dry race horse oats. The organic solvent used can be removed from the product and recycled. Using this procedure, the cost of the oat seeds needed to break down a pound of oil is $0.23 (retail). Since the oats can be reused, the actual operating cost would be lower. For industrial purposes it would not be necessary to defat the oats. The process has been demonstrated to work on butter fat, soybean oil, castor oil, cottonseed oil, olive oil, palm oil, tallow, lard, and corn oil. Edible fats and oils are often extracted from seeds using organic solvents. Therefore, there should be no reason why the fatty acids produced by this procedure could not be used in foods.

Patent Status:
U.S. Patent 5,932,458 issued August 3, 1999.

Responsible Scientist/Engineer:
Dr. George I. Piazza
Eastern Regional Research Center
ARS, USDA
600 East Mermaid Lane
Wyndmoor, PA 19038
(215) 233-6511
email: George.Piazza@ars.usda.gov

Technology Transfer Specialist:
Victor (Vic) Chavez
(215) 233-6610
e-mail: vic.chavez@ars.usda.gov