Colorimetric Characterization of Red Pear Cultivars

Abstract

Fruit color was characterized in eight red pear cultivars by measurement using the Commission Internationale d'Eclairage L* a* b* color space coordinates. Color was measured on sun-exposed and shaded fruit surfaces at mid-summer and three times during harvestable fruit maturity. All cultivars gained red color (a* value) on the sun-exposed surface during the growing season, but varied in yellowness (b* value). Hue angles calculated from these values described differences in color change and color at final harvest. Color response on the shaded fruit surface varied among cultivars to a greater extent than on the sun-exposed surface. ‘Rosired Bartlett’ and ‘Rogue Rea’ became darker (decreased in L* value) and redder (decreased in hue angle) with maturity on both sun-exposed and shaded fruit surfaces. All other cultivars became lighter and less red with maturity. ‘Rogue Red’ and ‘Cascade’ showed the greatest difference in hue between sun-exposed and shaded fruit surfaces, indicating a strong degree of bi-color. The least contrast between fruit surfaces was in ‘Starkrimson’ and ‘Gebhard Red Anjou.’