Subjective and Objective Pericarp Colour Measurement in Block‐Red Kiwifruit

Kiwifruit ( Actinidia chinensis ) genotypes include fruit with green, yellow, or red flesh. Red‐fleshed kiwifruit may be either starburst, with a red inner pericarp, or block red, in which both inner and outer pericarp are red. In the research reported here, the flesh colour of two block‐red A. chinensis var. chinensis genotypes has been evaluated during maturation. Red colouration was scored subjectively by eye and objectively as hue angle data. In addition, a spectrophotometer was used to collect the spectral reflectance light (360–740 nm) from the pared fruit surface. Chlorophyll and anthocyanin contents of fruit at the extremes of flesh colour were quantified. Data have been evaluated for the association between subjective and objective scores, which were noisy, along with changes during fruit maturation. The objective hue angle data gave clear quantification of fruit‐to‐fruit differences. The degree of red colouration differed between the genotypes with considerable fruit‐to‐fruit variation. Fruit in the 90°–100° hue range had degreened, but with no red colour, whereas at <70° fruit had marked red colouration, with maximal values in the range 40°–50°. The degree of outer pericarp red colouration is not indicative of maturity or ripening.