I'm looking for the definition of fractionated oil is. And how different is this from hydrogenated oil that you see so often on food labels.
Fractionated oils are ones where some of the fatty acid strains are separated. Often these are healthier oils because they separate and retain the essential fatty acid subsets with the vitamins connected (ie. Vit E) and let go of the saturated fatty acid chains that are less desirable.
First, let's discuss hydrogenation. Hydrogenation is the process that changes liquid vegetable oils into a more solid form in order to lengthen their shelf life. A good example is Crisco oil and vegetable shortening. Crisco oil is a liquid at room temperature; it is hydrogenated to produce solid Crisco vegetable shortening. The process of hydrogenation also increases the saturated-fat content. In general, foods that are less hydrogenated are preferred because they have less saturated fat.
Second, various types of oils. All oils contain saturated (the bad one), monounsaturated (the preferred one), and polyunsaturated (neutral) fats in varying percentages. We tend to encourage the moderate use of oils higher in monounsaturated and lower in saturated fats as a way to reduce the risk of heart disease. According to the Food and Drug Administration, "Vegetable oils should be labeled by their common or usual names, such as cottonseed, sunflower, peanut and sesame. Mixtures of edible oils should be labeled to show all the oils present, and the names should be listed on the labels in the descending order of predominance in the product. Terms such as 'vegetable oil' or 'animal shortening' are permitted, provided that the source of each oil or fat used in the product is disclosed."