The Xanthine Content of Guarana and Its Preparations

Abstract
The Identity Of Caffeine As The Major Xanthine Present In Guarana Has Been Confirmed By Spectroscopic Methods. Theobromine and Theophylline Were Present In Small Amounts But The Presence Of A Tetramethylxanthine Could Not Be Detected. Evidence Was Obtained For The Presence Of A Complex Of Caffeine and A Tannin. Hplc Was Used To Quantify The Caffeine Present In Various Samples Of Guarana and Its Products. The Amount Of Caffeine Present Was Found To Be Between 2.0 and 4.5% W/W Which Is Of The Same Order As That Present In Tea and Coffee.