Physicochemical difference of coffee beans with different species, production areas and roasting degrees

Abstract

In recent decades, the demand for coffee has seen a continuous increase, and the aroma and flavor of coffee has been widely studied. The current research chose coffee beans of two species (<i>Coffea arabica</i> and <i>C</i>. <i>canephora</i>) from five production areas (Brazil, India, Indonesia, Uganda and Vietnam) with four different roasting degrees (medium light, medium, medium dark and dark), to investigate the difference on physicochemical properties. The results showed that Arabica coffee beans had higher concentrations of fat and organic acids, and total amount of volatile compounds, whereas Robusta beans had higher concentrations of protein. With the increase of roasting degree, the concentrations of protein, fat, organic acids, and the total amount of volatile compounds of coffee beans increased, while the concentrations of chlorogenic acid compounds decreased. The discriminant analysis indicated that the tested coffee beans could be clearly discriminated by species and roasting degrees, but not by production area. The results of this research conclude the physicochemical difference of Arabica and Robusta beans with different roasting degrees. The results can provide a theoretical basis for coffee bean selection for the relevant industries.