ISHS Acta Horticulturae 475: VII International Symposium on Pear Growing
USING HUE DIFFERENCE TO DESCRIBE AND COMPARE BI-COLOR PEAR CULTIVARS |
| Authors: | D. Sugar, M.C. Dussi |
| Keywords: | Colorimeter, color, lightness, Hue-Angle, chroma |
| Abstract:
The color of eight red pear cultivars at final harvest was analyzed using a Minolta portable chromameter. This meter describes color in three coordinates: L*, lightness, from 0 (black) to 100 (white); a*, from -60 (green) to 60 (red); and b*, from -60 (blue) to 60 (yellow). At any level of lightness, the hue angle can be calculated as arctangent (b*/a*). Hue angle is a measure of color, which is highly correlated, with human experience of color discrimination. The hue angles describing the sun-exposed and shaded surfaces of each red pear cultivar were used to find the hue difference: the hue angle of the shaded surface minus the hue angle of the sun-exposed surface. A small hue difference represents greater uniformity of color, while a large hue difference indicates greater bi-color strength. Among the cultivars studied, the greatest color uniformity was seen in ‘Starkrimson’ and ‘Gebhard Red Anjou’, while the greatest bi-color strength was in ‘Rogue Red’, ‘Cascade’, and ‘Max Red Bartlett’. | |
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