Changes in the physical and physico-chemical characteristics of red-pulp dragon fruit during its development

The red-fleshed dragon fruit (Hylocereus polyrhizus) has high functional potential; however, but there have been only few studies on it. Knowledge about the changes that occur during fruit development facilitates the adoption of strategies that address issues related to fruit management, quality, conservation, and harvest. The objective of this study was to evaluate the quality evolution of red-fleshed dragon fruit at different development stages and to ascertain the ideal season for fruit harvest. The following parameters were evaluated: fruit, pulp and skin weight, yield, longitudinal and transverse diameter, firmness, skin thickness, pH, soluble solids, acidity, pulp and skin color. Measurements were taken every two days, from 28 to 42 days after anthesis. Significant physical and physico-chemical changes occured in red-fleshed dragon fruit during its development, including increase in soluble solids, pH, diameter and mass, as well as decrease in acidity, firmness, and skin thickness. Skin color and external appearance were found to be good indicators of the degree of maturity and can be thus be used to determine the fruit harvest point. From 34 to 42 days, the fruits showed characteristics appropriate for consumption and commercialization. Our findings demonstrate that the fruit should be harvested atat 34 days of anthesis or when the fruit skin is predominantly reddish, when destined to more distant markets. For marketing in nearby markets and immediate consumption, fruits should be harvested after 36 days or with intense red coloration.