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.

By extraction of the pericarp, after removal of the seeds, the content of both capsaicin and colour in the oleoresin can be substantially increased when compared with those in the oleoresin prepared from the whible fruits. This forms the basis of a patented method by which a cornpany in the United States produces oleoresin paprika; here, the capsaicin content is very small, but the product shows a marked enrichment of its colour.

Chillies and paprika may, therefore, be regarded as taking up posi- tions at opposite ends of a spectrum of common properties. On progressing from chillies through capsicums to the paprika varieties, there is a steady decrease in the pungency level and an increase in the pigment content. This transition is accompanied by a trend for an increase in the size of the fruits, but it should be noted that size is at best only a pragmatic indicator of the properties of the fruit, especially with regard to the pungency level.

The smaller-fruited types (C. annum cultivars, including var. glabriusculum, C. frutescens and C. baccatum) sold in the dried form as capsicums or chillies are considerably more pungent than paprika. Their capsaicin content ranges from about 0.1 per cent in mildly pungent capsicums up to 1.3 per cent in the very small chillies from Central Africa.