There are two source of trans fat. Firstly, trans fat is found naturally, in small amounts, in some animal foods, such as beef and dairy. The second source of trans fat is created when liquid vegetable oils go through a process called partial hydrogenation, which is used to improve the stability of oils. Partially hydrogenated vegetable fats are used by food manufacturers because they allow longer shelf-life and give food desirable taste, shape and texture. Commercially produced trans fat are found in margarine, biscuits, crackers, fried foods, pastries, baked goods, and other processed foods made with partially hydrogenated oils.