Guaraná (Paullinia cupana var. sorbilis): ecological and social perspectives on an economic plant of the central Amazon basin.

Guaraná is considered an ideal crop for supplementing the incomes of small peasant farmers in the Amazon basin. A fast-growing perennial, guaraná can be planted in the midst of manioc crops, allowing the formation of extensive orchards in the place of regenerating scrub once the manioc has been harvested. Traditional forms of guaraná agriculture practised by the Saterê-Mawé Indians compare favourably with the plantation system favoured by government agronomists. Indigenous techniques of hand-processing guaraná are also shown to produce better quality in the finished product than those practices adopted by industrial concerns. A detailed comparison of two systems of production show the Indians' implicit concern to avoid oxidization of the phenolic compounds in the seed, since this leads to the guaraná becoming dark in colour, bitter in taste, and irritating to the gastrointestinal tract. The short-term medicinal effects of guaraná are commonly thought to result from a high content of caffeine and associated alkaloids, as well as from considerable amounts of tannin. Future research may well show that various saponins also play an important part in the drug's pharmacology, particularly with regard to its long-term influence as a general tonic and prophylactic.