Biochemical and nutritional characterization of dragon fruit (Hylocereus species)

•White pulped dragon fruits are superior for yield & sugar content than to red ones.•Red pulped fruits are superior for dietary fibre, phenolics & antioxidants.•Rich in essential amino acids viz. histidine, lysine, methionine, & phenylalanine.•Rich in caffeic acid, ferulic acid, vitamin C, vitamin K1, potassium & iron.•Both types are an ideal fruit for maintaining good health as they have low calorie. Nutritional and biochemical composition of dragon fruit (Hylocereus) species H. undatus (fruits with white pulp and pink skin), and H. polyrhizus (fruits with red pulp and pink skin) were investigated to develop the nutritional composition data for dragon fruit and compare the difference between H. undatus and H. polyrhizus. The pH, TSS, total sugar, moisture, ash, protein, and dietary fibre content varied between 4.8 and 5.4, 8–12%, 5.13–7.06%, 82–85%, 0.7–0.85%, 0.90–1.1% and 0.8–1.0%, respectively. Total phenolics and flavonoids content varied between 25 and 55 mg GAE and 15–35 mg CE per 100 g, respectively. H. polyrhizus have a significantly high quantum of phenolics and antioxidant potential than H. undatus. 100 g fruit contained about 120–200 mg K, 30–45 mg Mg, 20–45 mg Ca, 20–35 mg P, 0.70–1.5 mg Fe, and 0.20–0.40 mg Zn. Vitamin C was found maximum (6 mg/100 g), followed by vitamin E (150 µg), pantothenic acid (50 µg), and vitamin K1 (25 µg). It is an ideal fruit for maintaining good health as it has low calories.