Electrical conductivity of coffee grain exudes I Methodology development (Coffea arábica L.).

Abstract

This paper aims to complement usual methods for coffee quality determination. The relation between electrical conductivity of coffee grains and its quality was studied. The methodology for evaluation of electrical conductivity was developed at the Seed Laboratory of the Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ-USP, Piracicaba-SP). Was recommended the use of 4 samples of 50 grains of coffee, weighed and immersed on 75ml of destilled water (in 180ml plastic glasses). Temperature was kept on 25°C for 3.5 hours, followed by shaking. The determination in electrical conductivimeter was expressed in uS/g/sample. The results showed that potassium was the most leached ion by coffee grains. The evolution of electrical conductivity follows the water absorption and potassium leaching.