margarine, manufactured substitute for butter. It consists of a blend of vegetable oils or meat fats (or a combination of both) mixed with milk and salt. It was developed in the late 1860s by the French chemist Hippolyte Mège-Mouries in a contest sponsored by Napoleon III for a butter substitute. Beef fat, known as oleo oil, was chiefly used at first, but later was supplemented by pork and other animal fats and by vegetable oils such as coconut oil, olive oil, and cottonseed oil. At present, most margarines contain only vegetable oils; the margarine produced in the United States is usually made from corn, cottonseed, or soybean oil. The oils, refined, deodorized, and hydrogenated to the desired consistency, are churned or homogenized, usually with cultured skim milk, then chilled and reworked to incorporate salt and remove excess water. Margarine is similar in composition to butter, yields practically the same number of calories, and is easily digestible. It is commonly fortified with vitamin A and vitamin D. In the 1960s a new type of margarine was developed made of polyunsaturated fats (see cholesterol). Margarine is sometimes called oleomargarine.