Comparative study of the physical and chemical characteristics of coffee and sensorial analysis by principal components

Abstract

The objective of this work is to compare properties of coffee under different post-harvest processing with its sensorial characteristics by principal component analysis (PCA) features, in order to help it, making it less subjective. Coffee fruits were harvested, and a part of them had their mucilage removed and, then, taken to the Laboratory of Physical Properties in the Federal University of Viçosa, Brazil. The coffee without mucilage was dried at temperatures of 40, 50, and 60 °C. Cherry coffee was dried at three different temperatures (40, 50 and 60 ºC); however, when subjected to 40 °C, coffee quality suffered an addition of 0, 10, 20, and 30 % of green fruits. The samples were subjected to analysis of color, electric conductivity, density, thousand grain masses, gas chromatography, and sensorial analysis in the beginning and at every 3 months of storage for 1 year. Through the PCA, it was possible to differentiate samples that were submitted to post-harvest processing. After 12 months of storage, it has been noted a similarity between groups differentiated by PCA of chemical and physical characteristics of coffee and groups differentiated by PCA of sensorial analysis. Compatibility between characterization techniques for PCA was observed, making the technique effective in helping the cup testing.