Abstract
The fatty acid constitution of oils from the seeds of eleven Amazonian species of Leguminosae, namely Acosmium nitens Yakovl, Bauhinia splendens Kunt, Caesalpinia ferrea Martius var. ferrea, Clathrotropis nitida (Benth.) Harms., Cynometria spruceana Benth., Macrolobium acaciifolium (Benth.) Benth., Ormosia excelsa Benth., Parkia discolor Benth., Peltogyne venosa (Vahl.) Benth., Stryphnodendron guianense Benth., Vatairea guianensis Aubl., were determined. The individual components of the oils were analyzed by gas chromatography coupled to mass spectrometry, using two columns having stationary phases with different polarities. The fatty acids were analyzed as methyl esters, prepared by alcaline hydrolysis of the triglycerides followed by treatment with diazomethane. The mixture of fatty esters was better separated in the more polar stationary phase (polyethylene glycol). Palmitic acid was representative (18% to 35%) in five species, being especially high (52%) in C. ferrea. The stearic acid content is significant (18% to 31%) in four species, rising to about 80% in B. splendens. Oleic acid constitutes 44% of the fatty acids in A. nitens and is representative (20% to 29%) in four other species. Other constituents, such as arachidic, behenic and lignoceric acids, are present at variable concentrations (up to 20%) in most of the samples. The presence of linolenic acid is also notable in S. guianense (15%) and C. spruceana (6.2%). The high crude oil yield of B. splendens (higher than 20%) suggests it as a potential source of stearic acid for industrial purposes. Seeds of five other species had crude oil content between 6% and 10%.