Nonglyceride Components of Edible Oils and Fats. 2. Nutritional and Health Significance

Edible oils and fats, which consist primarily of triglycerides of different fatty acids, also contain 1% to 10% of fat-soluble phytochemicals derived from oil-bearing seeds or fruits, collectively called the nonglyceride fraction. They belong to different classes of chemicals, each with a number of different chemical compounds. These chemicals are also present in the unsaponifiable fraction of oils and fats, some of them in a modified form. Several of these chemicals have been shown during the past two decades to have health-promoting functions, with vitamin, hypolipidemic, and antioxidant activities. Studies in experimental animals and humans have shown that they can have a preventive role in noncommunicable diseases, such as cancer, cardiovascular disease, and cataract. They also serve as a source of vitamin E and provitamin A. Thus, oils and fats in the nonglyceride fraction not only are sources of energy and essential fatty acids, but also have a disease-preventing and health-promoting role and can serve as a source of some fatsoluble vitamins. Certain edible oils, such as palm oil, rice bran oil, and sesame oil, are particularly rich in the health-promoting chemicals present in their nonglyceride fraction. Some of the edible unconventional oils have high levels of the nonglyceride fraction (8%–10%), and they may have important disease-preventing potential.