ANALYSIS OF THE CONTENT OF THE DITERPENES CAFESTOL AND KAHWEOL IN COFFEE BREWS

The diterpenes cafestol and kahweol have been implicated as the compon ents in boiled coffee responsible for its hypercholesterolaemic effect s. These particular coffee constituents have also been shown to posses s anticarcinogenic effects. A simple and sensitive reverse-phase HPLC method using solid-phase extraction has been developed for the analysi s of cafestol and kahweol in coffee brews. This method was used to con firm that the method of coffee brewing is a major determinant of the c up content and hence level of consumption of these diterpenes. Scandin avian-style boiled coffee and Turkish-style coffee contained the highe st amounts, equivalent to 7.2 and 5.3 mg cafestol per cup and 7.2 and 5.4 mg kahweol per cup, respectively. In contrast, instant and drip-fi ltered coffee brews contained negligible amounts of these diterpenes, and espresso coffee contained intermediate amounts, about 1 mg cafesto l and 1 mg kahweol per cup. These findings provide an explanation for the hypercholesterolaemic effect previously observed for boiled coffee and Turkish-style coffee, and the lack of effect of instant or drip-f iltered coffee brews. This methodology will be of value in more correc tly assessing the human exposure to these diterpenes through the consu mption of coffee, and hence the potential physiological effects of dif ferent brews. (C) 1997 Elsevier Science Ltd.