Vegetable Oils are oils that have come from some form of plant matter, be it from the seeds, nuts, fruit or sometime the peel of the plant. To extract some oils (such as that from an olive), you can simply crush the object into a paste, spread said paste over a pair of metal plates, crush the oil out of them, and filter and distill to purify the resulting product. In other cases (like sunflowers) you must dissolve the matter in a solvent and filter and distill to collect the oil. The chemical structure of Vegetable Oils consist of a glycerol part, with fatty acid parts stretching off from it
There are three scientific varieties of Vegetable Oils, which differenciate by their chemical structure. Saturated Oils have no double bonds, while Monounsaturates have a single double bond and Polyunsaturated Oils have two or more double bonds. The method in which producers change Mono and Polyunsaturated Oils into Saturated Oils is known as Hydrogenation, the products of which have a longer shelf life and higher melting point.