Location: Commodity Utilization ResearchTitle: Fatty acid composition of Tilia spp. seed oils Author
|Dowd, Michael - Mike|
Submitted to: Grasas Y Aceites Monograph
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2013
Publication Date: 4/1/2013
Publication URL: http://handle.nal.usda.gov/10113/57071
Citation: Dowd, M.K., Farve, M.C. 2013. Fatty acid composition of Tilia spp. seed oils. Grasas Y Aceites Monograph. 64(3):243-249. Interpretive Summary: Fatty acid composition was determined for the seed oils of a number of Tilia spp. seed oils. After extracting the oil and converting the fatty acid to more volatile esters, the fatty acids were analyzed by chromatography. The same unusual 17-carbon fatty acids found in cottonseed oil and Thespesia populnea seed oil were identified in these seeds. The acids appear to be products of alpha-oxidation, a secondary degradation process that is not fully understood in plants. The work will increase our knowledge of the oil composition of cottonseed and related plant species. The work should be interest to researchers trying to modify the fatty acid composition of cottonseed oil to improve its marketability.
Technical Abstract: As part of a study of the seed oil fatty acid composition of Malvaceae plants, seeds of seven Tilia species (limes or linden trees) were evaluated for their fatty acid profiles. Seeds were obtained from the Germplasm Research Information Network and from various commercial sources. After extraction of the seed oil with hexane, glycerides were trans-methylated and analyzed by gas chromatography with two polar stationary phases. All of the seed oils analyzed were composed primarily of linoleic acid (49-60%) with lesser amounts of oleic (16-22%) and palmitic (8-10%) acids. The usual secondary components were also found. In addition, cyclopropenoid acids (i.e., sterculic and malvalic acids) were present at levels between 5 and 16%. In all samples, the level of malvalic acid was approximately double the level of sterculic acid, indicating that considerable alpha-oxidation of sterculic acid had occurred in these seeds. Two additional alpha-oxidation products, 8-heptadecenoic acid and 8,11-heptadecadienoic acids, were also measured. Combined, the level of these fatty acids was between 1.3 and 2.3%, roughly comparable to the levels of these acids recently reported in the seed oil of Thespesia populnea.