Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 27, 1997
Publication Date: N/A
Interpretive Summary: Many older adults vividly remember when mother prescribed castor oil for their childhood illnesses! Fortunately, those days are gone, but castor oil isn't. Imports of the oil over the last 35 years have averaged 100 million pounds annually, because of its novel content of what are called hydroxy fatty acids that impart exceptional properties to many industrial products such as nylon plastics, waxes, cosmetics, coatings, lubricants and industrial fluids. USDA scientists are working to make a native U.S. plant, Lesquerella, an option for farmers to grow, because it too has hydroxy fatty acids in its seed oil. But, to be practical, the Lesquerella hydroxy acids must be easily isolated from the oil in very pure form. A method of doing this, called low temperature crystallization, has now been discovered and shown to be practical on a large laboratory scale. This is a significant step in the product development side of commercializing Lesquerella, which when achieved will reduce our reliance on imported castor oil.
Technical Abstract: Lesquerolic and auricolic acids were obtained from hydrolyzed lesquerella oil by a low temperature crystallization procedure. The lesquerolic and auricolic fatty acids fraction was enriched from 55-59% to 85-99% with high yields (94%). Washing the free fatty acids with pH=6.0 buffer provided reproducible crystallizations of these hydroxy fatty acids. In contrast, when hydrolyzed oil from L. fendleri was not buffer washed there was, in most cases, no separation of hydroxy fatty acids by crystallization. This crystallization procedure is suitable for a large scale separation process of the hydroxy fatty acids from non-hydroxy fatty acids obtained from hydrolyzed lesquerella oil.