Abstract: This study examined the nutritional composition and the antioxidant properties of unripe papaya (
Carica papaya L. var BARI Papaya-1) peel powder which could be an ideal functional food source to be incorporated into food products in the future. From the analysis, it showed that the peel powder is rich in nutrients containing protein (10.51%), crude fiber (15.58%), moisture (9.41%), ash (6.33%), carbohydrate (57.07%) and energy ( 280.24 kcal/100 g ). It further revealed substantial content of bioactive vitamins with antioxidant activity, such as vitamin C (60.6 mg/100 g), ?-carotene (2952.08 µg/100 g), and vitamin A (246.01 RE/100 g). The results indicated that the peel powder had total phenolic content (1216.75 mg GAE/100 g DW), total flavonoid content (158 mg QE/100 g DW), and excellent total antioxidant activity (161.75 mg/100 g DW). The free radical scavenging ability was remarkably higher in peel powder in particular, with the highest DPPH radical inhibition of 74.41% obtained from the 80% methanolic extract of peel powder. Thus, these results indicate that the unripe peel powder of papaya can be used as a potential source of nutrients and antioxidants for health-promoting food and nutraceutical applications.