Kinetic Study of Mineral Ion Extraction from Kenyan Arabica Coffee

Abstract

The rate of infusion into distilled water of caffeine and of Mg, Mn, K and P have been measured. The coffee used was roasted Kenyan Arabica coffee, ground, and sieved to a size range of 1.70–2.00 mm. The analytical techniques employed were HPLC for the analysis of caffeine and ICP-AES for analysing mineral ions. The kinetic data have been interpreted in terms of a steady-state theory, and the rate constants of infusion have been calculated. The diffusion coefficients of the various species within the bean were calculated from the resultant rate constants. These values have been compared with the corresponding diffusion coefficients in pure water at 80°C and the hindrance factors in the bean have been determined.