At the present time there is a very lively interest in oilseed crops as a whole. This arises from a number of causes but principally the fact that the supply of animal fats and oils has been reduced as a consequence of conservation measures taken in the interests of whale populations. Perhaps more importantly, the role of saturated animal fats in human diets and nutrition has been called in question. This has led to an increased demand for polyunsaturated plant edible oils, which the supply of long established traditional oilseed crops has not been able to meet. This has meant that oils which twenty years ago were used almost entirely in industry are now extensively used in the food trade. The longerestablished traditional oils, from the olive, groundnut and sesame, have been substantially replaced in part at least by a later generation of oilseeds: sunflower, soyabean, rapeseed, mustard and cottonseed, for example. Production of the traditional oils could not keep up with increased demand; there seems to be little prospect, for example, of a substantial increase in olive oil production. The very high culinary quality of oils such as olive and groundnut oils and their high cash value has led to problems of adulteration. Adulteration is not always easy to detect and control, with the increased tendency for oilseeds to be expressed in the country of origin.