Discrimination Between Coffee Species (Coffea arabica
and Coffea canephora) by the Content of Kahweol and Cafestol
F.G. CAMPANHA, R.C.E. DIAS, M.T. BENASSI
Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina,
Rodovia Celso Garcia Cid, km 6, Londrina, Brazil
SUMMARY
Commercial coffee is mainly accounted for by two species: Coffea arabica (arabica) and
Coffea canephora (conilon). Since these species differ in their commercial value, quality, and
acceptability, adulteration and mislabeling are major concerns. High performance liquid
chromatography (HPLC) has been used to characterize the composition of coffee samples and
discriminate the species. The degree of roasting alters the levels of several constituents.
Defective beans may also affect the final composition of the product. The aim of this work
was to evaluate the possibility of discriminating arabica and conilon coffee species by their
kahweol and cafestol contents. Samples of arabica, conilon, and their blends with different
degrees of roasting and amounts of defective beans were investigated. After direct
saponification and extraction with 3°butyl methyl ether, the samples were analyzed by
reverse-phase HPLC with UV detection. A predictive model was generated and validated to
estimate the proportion of conilon added to arabica coffee. The addition of conilon coffee
reduced the diterpenes content. A linear model using kahweol and cafestol concentrations
allowed a good fit (R2 = 0.93) and the highest predictive power. Kahweol and cafestol showed
potential for discrimination of coffee species.