Determination of size and shape in the 'Moro' blood orange and 'Valencia' sweet orange cultivar and its mutants using image processing

Abstract

Fruit size and shape are important physical characteristics in designing relevant equipment, sorting, sizing and packaging systems. Therefore, the properties of size and shape of the sweet orange cultivar, 'Valencia', and its three mutants, 'A70', 'A77', and 'A88' were determined by image processing. The blood orange cultivar, 'Moro', was also included in this analysis. The volume of each cultivar and mutant was measured by the liquid displacement method. Linear equations with high R2 values were developed in order to estimate the surface area and geometric mean diameter, which were dependent upon the mass and volume of the orange samples. The results of this study showed that the 'A70' mutant differed from the other mutants and the 'Valencia' cultivar in regard to most physical properties. The 'A70' and 'A88' mutants and the 'Valencia' cultivar had the highest sphericity values, which varied from 96.41% to 97.18%. The lowest shape factor was found in the 'Valencia' cultivar, with a mean of 0.73. The elongation of the 'A88' mutant and 'Valencia' (1.07 each) was smaller than that of the other cultivars. The highest coefficient of variance was observed within the 'Valencia' and 'Moro' cultivars in most physical properties, suggesting that the 'Valencia' mutants produce more homogeneous fruits than the 'Valencia' cultivar itself.