Process of Hydrogenation

Hydrogenation is a commercial process that makes fats and oils more solid, allows them to be heated to higher temperatures before smoking, and increases their shelf life or that of the foods coated with them. The process of hydrogenation is facilitated with the aid of a metal catalyst (nickel, copper, platinum, or paladium) and the presence of pressure and heat. The catalysts are removed after the process is completed. The degree of hydrogenation, or the number of hydrogen atoms added, determines the firmness of the final product.

Through this process, vegetable oils may be convered to spreadable hydrogenated shortenings or margarines. Too much hydrogenation, however, will cause the product to become brittle and hard. In addition to affecting plasticity, hydrogenation contributes to making pie crusts flaky, puddings creamy, and processed foods stay on the shelf longer.

One of the side effects of hydrogenation is that more trans than cis configurations are created at the double bonds. The benefits to a higher concentration of trans fatty acids are a rise in the fat’s melting point, increased solidity, and lengthened shelf life. The long-term health effects of trans fatty acid intakes have yet to be determined, however. Among other health risks, trans fatty acids have been reported to increase the risk for heart disease.