Process standardization and evaluation of free flowing dragon fruit powder

Dragon fruit ( Hylocereus sp .) is gaining popularity in India as a minor tropical fruit crop. However, due to its high perishability, drying is one of the viable method for its long term preservation. In this study, low-cost tray drying was used to produce dragon fruit powder using different hydrocolloids viz ., maltodextrin, corn starch and carboxymethyl cellulose (CMC) in different combinations and different levels ranging from 2–64% of the pulp weight. The dragon fruit pulp without additives served as a control. The results indicated the additive combination predominantly made up of corn starch was the only one able to produce free-flowing dragon fruit powder. The results also revealed that the powder recovery percentage, lightness ( L *) and bulk density increased with increasing additive concentrations, while the concentration of physico-chemical parameters in the powder showed a declining trend. Further, the study pointed out that the dragon fruit powder with the lowest level of additive incorporation (4%) had the highest nutrient retention after drying, with values for titratable acidity (0.98%), total sugars (49.73%), ascorbic acid (10.83 mg/100g), total betalins (361.39 mg BCE/100g), total phenols (466.70 mg GAE/100g), flavonoids (409.34 mg CE/100g) and antioxidant activity (DPPH-59.57% RSA). The perusal of the investigation suggests that the use of a low concentration of additives combination containing corn starch as principle ingredient (4%) has the potential to produce free flowing dragon fruit powder for use as a functional ingredient in the food industry.