Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2002
Publication Date: March 16, 2002
Interpretive Summary: Milkweed oil is very unsaturated but cannot compete successfully in the huge edible oil market because of the present limited size of the milkweed crop under cultivation. This oil would do very well in a low-volume, value-added niche market. In order to improve the economics of the new crop, we have modified (with hydroxyl chemical groups) the oil to enhance its behavior for a variety industrial applications. Additionally we have studied the flow characteristics of the modified oil compared to the major inported castor oil which is hydroxy vegetable oil. The results demonstrate that hydroxy milkweed oil is a viable competitor for castor oil in cosmetics. Improved products from milkweed oil will result in increased production of this new alternative crop in the Midwest.
Technical Abstract: Asclepias syriaca L, the common milkweed is a new industrial crop. Its fine silky fiber which naturally adapts the seed for wind dispersal is hypoallergenic and is used in pillows and comforters. The seed contains about 0-30 wt.% of a highly unsaturated oil having unusual fatty acids. Exploring value-added products from the oil, milkweed trglycerides have been oxidized by in situ performic acid to the polyoxirane and polyhydroxy triglycerides (PHTG). The rheological properties of milkweed PHTG were characterized in various shear flows. Milkweed PHTG displayed nonlinear viscoelastic behavior at applied strains greater than 1%. Milkweed PHTG was found to obey time-strain separability. A nonlinear Wagner constitutive model was used successfully to predict the behavior of Milkweed PHTG in both start-up and cessation of steady-state shear flow.