In this post we will define what the hydrogenation in food processing is as well as what it entails.
Hydrogenation is among the most significant processes in the vegetable oil industry, chiefly in the synthesis of edible fat products. It produces fats utilized in a broad variety of products that would have otherwise been impossible with unmodified forms. It influences changes in physical properties of oil, i.e the crystalline structure and melting point. Hydrogenation is a process that involves the addition of hydrogen atoms to unsaturated fatty acids (contain double bonds) resulting in the solidification of oils.
Usually, unsaturated fatty acids are in liquid form, the addition of hydrogen atoms changes their liquid state to either semi-sold or solid form. Hydrogenation is an important practice in the changing of consistency, enhancing flavour and extension of shelf stability. Oils in an unhydrogenated form easily turn rancid as the free carbon atoms can bond with oxygen atoms found in air to create peroxides that lead to rancidity.
Common products of the hydrogenation process are margarine and shortening fats. These products are used mainly in confectionaries. Though, its products comprising trans-fats are linked to increased likelihood of chronic disease if consumed regularly.
A successful hydrogenation process relies on the selection of a proper catalyst that should be handled carefully, alongside the application of appropriate equipment and operating mechanisms. The main catalyst employed is nickel due to its versatility and its cost-effectiveness. Oil and powdered nickel are injected into pressure tank. At temperatures of about Hydrogen atoms are added to the oils in no particular sequence. All components are stirred simultaneously to dispense the gas to the liquid oil. The high pressure, high temperatures and nickel catalyst facilitate conditions that allow the free carbons to bond with hydrogen atoms. As the process continues, the oil begins to solidify. This results in the shifting of double bonds away from their natural forms leading to the manufacture of trans-fats. Hydrogenation can be categorized into either partial hydrogenation that involves adding hydrogen atoms to unsaturated fats without the completion of saturation or complete hydrogenation involves the addition of hydrogen atoms to unsaturated fatty acids. In partial hydrogenation, while most molecules undergo hydrogenation, others do not. This degree of hydrogenation varies depending on the consistency intended to be achieved. Most vegetable oils undergo partial hydrogenation and not complete hydrogenation as the products of complete hydrogenation are usually like saturated fats and they cannot be applied for confectionaries because of their hardness. The aim is usually to achieve a product with a consistency that is not too hard or too liquid, mainly achieved by partial hydrogenation.
Hydrogenation involves the addition of hydrogen atoms of unsaturated fatty acids to produce more solid fats. It aims to produce edible fats that maintain solid state at room temperature, have a longer shelf life, and enhanced flavour. Usually, these products are used in confectionaries. This process is extensively used to produce products such as margarine and shortening fats. The double bonds are removed as hydrogenation takes place as carbon atoms combine with hydrogen atoms.