New Process Produces Lower Trans-Fat Foods

Margarine and other foods can be made with a lower percentage of trans fatty acids using a new process developed by Agricultural Research Service scientists. This is good news for consumers because other studies have shown that trans fatty acids may slightly increase blood cholesterol levels.

The new technique, developed by ARS chemist Gary R. List at the National Center for Agricultural Utilization Research (NCAUR) in Peoria, Ill., is called low-trans hydrogenation. By using a hydrogenation reaction with carbon dioxide, it makes a product with less than 10 percent trans fatty acid content, suitable for use in margarine and other tablespread formulations.

Margarine oils are usually prepared using hydrogenation or another conventional method, interesterification. Hydrogenation changes the chemical structure of oils to yield a margarine that doesn’t melt at room temperature, but the hydrogenated product contains 10 to 30 percent trans fatty acids.

Interesterification rearranges the oil’s fat molecules without adding hydrogen molecules to make a product with few trans fatty acids. Its drawback is that the process is more expensive than hydrogenation.

But List’s low-trans hydrogenation alters the chemical bonds of the vegetable oil and produces an oil with a much lower percentage of trans fatty acids. The researchers are currently seeking an industry partner to continue this development.

This is one of many uses for an environmentally friendly processing method that Peoria-based scientists are developing.

ARS is the U.S. Department of Agriculture's chief scientific research agency.