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United States Department of Agriculture

Agricultural Research Service


item Abbott Dr, Thomas
item Wohlman, Alan
item Momany, Frank

Submitted to: Industrial Crops and Products International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/16/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Natural lipids and oils are used in pharmaceutical preparations, food products, cosmetics, and various industrial products such as lubricants, coatings, inks, paints, plastics and the like. These lipids are subject to oxidative degradation which can affect color, odor, viscosity, and lubricity characteristics of the oils, adversely affecting the quality of the commercial products containing the lipids. Meadowfoam (Limnanthes alba) seed oil has been demonstrated to be highly stable to oxidation. Mixing meadowfoam oil with other oils imparts enhanced oxidative stability to the mixture. Refined meadowfoam oil (and other refined seed oils and vegetable oils) exhibit reduced oxidative stability as a result of the refining process. We found 1,3-di(3-methoxybenzyl) thiourea (3MBTU) to be one reason for the oxidative stability of meadowfoam and synthesized it. Addition of 0.1% to 1.0% of 3MBTU increased the OSI time of jojoba oil from 30 to 240% and refined meadowfoam oil from 15 to 218% at 110C. At 130C, refined meadowfoam oil stability was increased by 234%, to 1,054%. An addition of 1% of 3MBTU to high oleic sunflower oil increases its OSI time at 130C from 9 hr to 157 hr. Soybean oil and milkweed are increased in OSI time 8-fold and 6-fold at 130C with this antioxidant. Computer models of 3MBTU compared to commercially available 1,3-bis(2-methoxyphenyl)-2-thiourea show that the conformations of of 3MBTU allow easier access to the sulfur which explains why 3MBTU outperforms the phenyl derivatives.

Last Modified: 06/28/2017
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