Trans fats and hydrogenated fats are making the health headlines today and we are time and again advised to avoid them. People are aware about trans fats being the cause of heart disease but little do they understand about them and the foods they are found in.
Trans fats are fatty acids which have altered chemical structures. They interfere with the correct functioning of healthy fatty acids. They are largely artificial fats even though a small amount is found in meat and dairy products.
Artificial trans fats are created when vegetable oils are partially hydrogenated, by a process that converts the naturally occurring "cis" unsaturated double bonds in vegetable oil fatty acids into “trans” unsaturated double bonds. A simple change from the "cis" (or "same side") configuration of the hydrogen atom to the “trans” (or “opposite side”) configuration yields a fatty acid with very different properties, ultimately called as hydrogenated fat.
Foods with TFA’s (Trans Fatty acids) are attractive to food manufacturers because the liquid vegetable oil converts into a solid or semi-solid fat at room temperature, which finds an easy application in various cooking processes.
Partial hydrogenation also destroys omega-3 fatty acids, so that the vegetable oil is less likely to become rancid, resulting in a longer shelf life.
Most commercially prepared foods contain trans fats.
Trans fats could be present in the diet in the forms listed below:
As artificially produced trans fats (by the chemical process of hydrogenation)
(Partially hydrogenated vegetable oil commercially known as dalda, vanaspati, margarine)
Partially hydrogenated vegetable oils can replace naturally solid, saturated rich fats such as desi ghee and butter in baked and fried foods like muffins, pies, pastries, chips, biscuits, cookies, puffs, croissants, desserts, confectionery, salad dressings, chocolates etc.
Most bakery products and any food label having the words “hydrogenated fat”, “partially hydrogenated oil” contains trans fats. They can even replace commercial frying where vegetable oil cannot be used.
Produced by subjection to high temperature
Trans fats are formed when oil is exposed to high temperatures. Eg. -
► Refining of vegetable oils
► High temperature heating/ reheating of same oil during frying or refrying
► In the process of baking both at household and commercial levels.
Naturally found trans fats
Trans fats are found naturally in small amounts in meat and dairy products but their effect on health varies from the artificially-produced ones.