Sweet Cherry Skin Colour Measurement as an Non-Destructive Indicator of Fruit Maturity

Colour measurement is one of the methods used to evaluate food quality. Aim of completed research was the evaluation of a fast and non-destructive method which consisted of assessing colour changes. It was used to determine the ripeness of cherries during their harvest. Additionally, the most significant parameter determining fruit ripeness was identified. Colour measurements of the Burlat cherry on the PHL A rootstocks were supposed to provide standards for practical evaluation of fruit ripeness of this species at an orchard. During the research, the measurements concerned the internal quality of the cherry fruit (firmness, extract content) and the force required to tear off the stem, depending on the size of the fruit. The extract appeared to be the most important indicator to be used for the determination of an optimum harvesting period. It was most prominently correlated with the cherry’s colour. Changes in the skin colour were the most reflected by the value of the parameter CIE a*. The coordinates CIE L* and b* are also important for the determination of fruit quality. Burlat cherries achieve their optimum harvesting ripeness if the coordinate a* is within the range 30.0 to 0.0, the coordinate b* within 10.0 to 0.0 and the coordinate L* within 30.0 to 20.0, which corresponds to the extract value of 12-20%.