Physical-mechanical characterization of coffee fruits Coffea arabica L. var. Castillo classified by a colorimetry approach

Abstract

Colombian coffee is internationally recognized for its quality and flavor, reflected in its natural acidity, medium body, and intense aroma. These features require predominately harvesting ripe fruits (only 2% of unripe fruits are allowed) which is carried out manually by several topographic restrictions. To overcome this difficulty, the study of coffee fruit physical and mechanical characteristics is essential for designing and improving machinery and equipment for selective coffee harvesting. In this paper, the physical and mechanical properties of Coffea arabica L. var. Castillo fruits have been experimentally measured and classified by its ripening. Applying a colorimetry methodology based on CIELab color space, 211 fruits have been categorized into four ripening states. Physical properties measurements include mass, volume, density, geometry, pH, and mechanical properties as detachment loads and firmness indexes. Mainly all properties showed a dependence degree on the ripening stage of the fruits. The measurements presented in this work are essential to use in simulations tools which allows to understand several aspects related with selective coffee harvesting.