Colorimetry parameters and wood density for Amazonian species

Abstract

Even though wood color is a subjective parameter, it can now be measured. Colorimetry is a technique that can be performed with specific tools, allowing a color to be identified and recorded by associating it with a numerical value. This study aims to relate the color of 11 Amazonian woods, on the tangential plane, to their basic density, using the CIEL a*b* system. The colorimetric parameters assessed were: lightness (L), red-green axis (a*), yellow-blue axis (b*), color saturation (C*), and color hue (h*), in addition to the physical parameter, bulk density. Shapiro-Wilk test, Spearman's correlation, and cluster analysis were performed to attest normality of data, correlations, and similarities between species, respectively. The grouped species showed correlations ranging from strong to weak. The strongest correlations were: (b*) positively correlating with (C*) and (a*) negatively correlating with (h*). The weakest correlations were: (L*) with (C*), and (a*) with (b*). Peltogyne sp. wood (Peltogyne sp.) did not form a group due to its peculiar colorimetric characteristics, and jatobá (Hymenaea sp.) was classified with yellowish tones and grouped as a medium-density wood, showing that high-density wood does not necessarily exhibit a dark color.