Hydrogenation is a chemical reaction where hydrogen (H₂) is added to another compound, typically in the presence of a catalyst. This process is commonly used to convert unsaturated fats (which have double bonds) into saturated fats (which have single bonds), making them more solid at room temperature.

A classic example is the hydrogenation of vegetable oils. These oils are often unsaturated, containing double bonds between carbon atoms.

During hydrogenation:

Unsaturated Fat + H₂​ →Saturated Fat

Hydrogen molecules (H₂) are added across the double bonds of the unsaturated fat. This converts the double bonds into single bonds, effectively saturating the molecule with hydrogen atoms.

The catalyst, often a metal like nickel, palladium, or platinum, is crucial as it speeds up the reaction without being consumed in the process.

Hydrogenation is widely used in the food industry to convert liquid oils into semi-solid or solid forms, like margarine and shortening. This process can also increase the shelf life of food products. However, it can produce trans fats, which have been linked to various health issues