Comparative evaluation of total phenolic content, total flavonoids content and antioxidants activity in Skin & Pulp extracts of Cucurbita maxima

The aim of this study was to determine the total phenolic content, total flavonoids content, and antioxidant activity of various extracts of pumpkin Cucurbita maxima skin and pulp. The various solvents used for extraction were acetone, methanol, ethanol and water. The total phenolic content in pulp extracts ranged from 9.72 ± 0.37 to 106.92 ±0.47 mg GAE/g of extract, while in skin extracts ranged from 55.91 ± 5.67 to 336.19 ± 0.89 mg GAE/g of extract. The total flavonoids content varied from 0.13 ± 0.01 to 2.21 ±0.06 mg CE/g of extract in pulp extracts and from 1.17 ± 0.08 to 4.64 ± 0.02 mg CE/g of extract in skin extracts. Antioxidant activity of extracts was expressed as percentage of 2, 2-diphenyl-1-picrylhydrazyl (DPPH), IC50 values (mg/ml), and radicals inhibition. The IC50 values in pulp ranged from 1.55 to 4.01 mg /ml and from 1.12 to 67.64 mg/ml in skin. The highest antioxidant scavenging activity was obtained in water skin extract (lowest IC50 value of 1.12 mg/ml). The Cucurbita maxima skin extracts contains impressively higher total phenolic and total flavonoids contents when compared to pulp extracts. The present study revealed that the skin followed by the pulp of pumpkin Cucurbita maxima could be used as an excellent natural source of antioxidant.