Production of oleoresin paprika is a comparatively new development – post Second World War – and has become commercially significant in about the last 12 to 15 years. The oleoresin is obtained, mainly by processors in the United States, Canada and the United Kingdom, from selected paprikas imported from Spain, Hungary, Yugoslavia, Bulgaria, Morocco or Ethiopia.

In the United States, a flourishing paprika industry has been developed in California since the last war, and a substantial part of this crop is processed domestically into oleoresin. The oleoresin is produced by the conventional method, using (normally) acetone, dichloroethane or trichloroethane as the solvent, and yielding, according to Naves (1974), 4 to 8 per cent with acetone and 4.5 to 11.6 per cent with dichloroethane. Todd (1959) has reported a method of extraction which differs from the conventional process in that fresh peppers are used instead of dried fruits.

It has been mentioned previously that the fruits of Capsicum species vary widely in their size, shape, colour, flavour and pungency and this is reflected in the relative abundance of certain constituents. The composition of the freshly picked fruits is determined by the species, the cultivar, the environmental conditions of growth and the stage of maturity at harvest. Further changes in the relative abundance of some constituents can also occur post-harvest during after-ripening (‘curing’), drying, processing and storage.