Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/17/2004
Publication Date: 10/18/2004
Citation: Hojillaevangelist, M.P., Evangelista, R.L. 2004. Properties of proteins in lesquerella, cuphea and milkweed seeds[abstract]. American Chemical Society. p.75:50. Interpretive Summary:
Technical Abstract: Lesquerella and cuphea are being developed as other sources of industrial oils. Lesquerella oil is an alternative to castor oil as a source of hydroxy fatty acids (HFA), which are used in the manufacture of plastics, paints, lubricants and cosmetics. Cuphea is rich in medium chain fatty acids (MCFA), which are used in detergent, cosmetics, and lubricants. Milkweed, on the other hand, is grown mainly for the production of floss used as hypoallergenic fillers in comforters and pillows, and the seeds end up as by-products. Successful commercialization of these crops will generate substantial quantities of protein-rich co-products. Currently, there is very little information available on lesquerella, cuphea, and milkweed proteins. This investigation was conducted to study some chemical and functional properties of proteins in lesquerella, cuphea, and milkweed seeds to help identify possible value-added uses of these alternative crops. Proximate analyses determined that lesquerella contained 23% crude protein (dry basis), cuphea had 21%, and milkweed had 30%. SDS-PAGE revealed 11 protein bands in lesquerella, with the darkest bands resolving at MWs of 45, 30, and 10 kD. These intense bands were highly correlated to the salt-, water-, and ethanol-soluble proteins in lesquerella. Six protein bands were detected for cuphea. The darkest bands had MWs of 45, 30, and 15 kD and represented mostly the ethanol- and alkali-soluble proteins. Milkweed showed 13 protein bands, with the darkest bands corresponding to MWs of 45, 36, 19, and 6 kD. The dominant protein fractions were water- and salt-soluble. Solubility profiles showed that only 28% of lesquerella protein was soluble at pH 7, but solubility increased to 60% at pH 10. Cuphea protein had poor solubility (10% at pH less than 7, but at pH 10, its solubility was 88%. Milkweed protein was the most soluble at pH greater than 7 (70-90%).