ARS | Publication request: CHARACTERIZATION AND FUNCTIONAL PROPERTIES OF MILKWEED SEED PROTEINS

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract
Publication Acceptance Date: January 8, 2007
Publication Date: May 13, 2007
Citation: Hojilla-Evangelista, M.P., Evangelista, R.L., Wu, V. 2007. Characterization and functional properties of milkweed seed proteins [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 145.

Technical Abstract: Milkweed (Asclepias spp.) is a crop grown mainly for the production of floss used as hypoallergenic fillers in comforters and pillows, and the seeds end up as by-products. Milkweed seed contains 21% oil and 30% crude protein (dry basis). The oil is similar in quality to soybean oil, but there is no information on the properties of milkweed protein. This study determined the MW of major fractions, soluble classes, and functional properties of milkweed seed protein. Ground, defatted milkweed seeds were analyzed for proximate composition and subjected to SDS-PAGE and protein functionality tests. Reduced proteins showed eight distinct bands with MW ranging from 6.5 to 59.3 kDa. The dominant protein classes were water- (22%) and salt-soluble (15%). Solubility of milkweed seed protein was lowest (12%) at pH 4, 40% at pH 7, and reached a maximum (60%) at pH 10. The protein produced substantial foam volumes, but foam stability was poor. Its emulsifying capacity was excellent, especially at pH 10, and emulsions formed were stable. Water-holding capacity and surface hydrophobicity index values were higher at pH 7 than at pH 10. These results showed that milkweed seed protein has functional properties that may find use in food and nonfood applications.