Fats and oils are obtained from vegetable and animal sources. Their main constituents are mixed triglycerides (esters of glycerol) having long-chain carboxylic acid moieties. A large proportion of the vegetable oils such as coconut, palm and palm kernel oil come from countries with tropical climates. Soybean, rape seed and sunflower oils come from moderate climates. Animal fat is obtained from the meat industry with beef tallow being the most abundant fat.
Fats are an essential nutrient in the human diet For most individuals, it is appropriate to get 30% of one's daily food energy from fats and oils, evenly divided between monounsaturated, polyunsaturated, and saturated fats. Many cooking oils are known sources of various vitamins (A and E), minerals, amino acids, essential fatty acids, and antioxidants.
Handling and Storage of Oils
Whether refined or not, all oils are sensitive to heat, light and exposure to oxygen. Rancid oil has an unpleasant aroma and acrid taste, and its nutrient value is greatly diminished. It is best to store all oils in the refrigerator or a cool, dry place. Oils may thicken, but if you let them stand at room temperature they will soon return to liquid. To prevent negative effects of heat and light, take oils out of cold storage just long enough to use them. Refined oils high in monounsaturated fats keep up to a year, while those high in polyunsaturated fats keep about six months. Extra-virgin and virgin olive oils keep about a year after opening. Olive and other monounsaturated oils keep well up to eight months; unrefined polyunsaturated oils only about half as long.
Bio diesel has gained worldwide popularity as an alternative energy source. Bio diesel is manufactured from transesterification of vegetable oils, and it is basically a mixture of methyl esters. It is a light and lubricating oil and can run in most Diesel engines including trucks, generators, boats, trains, busses, and cars. With little or no modifications it can just be used in the fuel tank of Diesel engines. Tests done have shown that engines running on bio diesel have minor, if any differences, in torque, horse power, range, and top speed to those running on petroleum-based diesel. In fact, engines running bio diesel were generally found to run smoother. Diesel engines can run 100% on bio diesel or in combination with traditional diesel fuels as a blend. Maybe more importantly, bio diesel is biodegradable, non-toxic, and essentially free from sulphur and aromatics. This will help reduce our future dependence on popular fossil fuels. Still, the major challenge of bio diesel’s success hinges on the world’s vast network of petroleum-based distribution outlets taking on this alternative fuel. United Oil is not presently involved in this industry segment.