http://www.britannica.com/EBchecked/topic/364635/margarinefood product made principally from one or more vegetable or animal fats or oils in which is dispersed an aqueous portion containing milk products, either solid or fluid, salt, and such other ingredients as flavouring agents, yellow food pigments, emulsifiers, preservatives, vitamins A and D, and butter. It is used in cooking and as a spread. Nutritionally, margarine is primarily a source of calories.The French chemist H. Mège-Mouriès developed margarine in the late 1860s and was given recognition in Europe and a patent in the United States in 1873. His manufacturing method was simplified in the United States into a process in which the melted fat blend was churned with milk and salt, chilled to solidify the mixture, kneaded to a plastic consistency, and packaged, all by means of the standard butter-working equipment of the time. The edible fats used have varied widely, the trend having been from the animal fats predominant in early use to the vegetable fats, principally cottonseed, soybean, coconut, peanut, and corn oils, and, more recently, palm oil. During the late 1950s an increased interest in the relation of polyunsaturated fats and oils to health hastened the shift to corn, safflower, and sunflower oils as the fat ingredients of margarine. Whale oil has been widely used in Europe but was never common in the United States.Margarine was long subjected to severe restrictive legislation, particularly in the United States, because of the opposition of the dairy industry. But during the 1930s, margarine manufacturers learned to make margarine from domestic oils rather than the imported oils formerly used, thereby enlisting the support of U.S. cottonseed and soybean farmers. Repeal of federal and most state restrictions gradually followed, leading to the acceptance of margarine in the United States to an extent comparable with that in most European countries.