Characterisation of Morphological and Chemical Traits of Costa Rican Fruits from Purple Pitaya (hylocereus Sp.) Genotypes

Purple-fleshed pitayas (Hylocereus sp.) are cactus fruits commercially cultivated outdoors in tropical regions like Central America and the Far East, or under artificially shaded conditions in Israel. Pitayas can be freshly consumed but also employed as a natural food ingredient and colourant due to their high contents of betalains. Betalains are water soluble nitrogenous yellow-orange to red-purple pigments exerting broad pH stability and high antioxidant activity. Most studies on pitaya properties, composition and fruit development have been conducted on a limited number of Hylocereus clones cultivated in Israel. However, little is known about genotypes growing in their natural habitat. Therefore, the present work aimed at a thorough characterisation of pitaya genotypes cultivated in Costa Rica during fruit ontogenesis until full ripeness. Besides overall appearance, betalain patterns, together with chemical parameters such as soluble solids, total acidity, organic acids, sugars, pectin, but also firmness, have been assessed. Moreover, the betalain and phenolic profiles, together with antioxidant activities and colour properties of pitaya juices from the different genotypes were studied. Finally, these data should be useful to classify the genotypes with respect to their potential exploitation, and to differentiate fruits from diverse provenances.