Using genetic manipulation to modify the activity of a plant enzyme, researchers at the U.S. Department of Energy's Brookhaven National Laboratory have converted an unsaturated oil in the seeds of a temperate plant to the more saturated kind usually found in tropical plants. The new tropical-like oil has properties more like margarine than do temperate oils, but without the trans fatty acids commonly found in margarine products. Furthermore, engineered oils could be used to produce feedstocks for industrial processes in place of those currently obtained from petrochemicals. There is also the possibility that the genetic manipulation could work in reverse, allowing scientists to engineer more heart-healthy food oils.