Antioxidant activity and mineral content of watermelon peel

Both synthetic and natural antioxidants are using in the food industries. The evaluation of the former showed its potential carcinogenic effects. So, different studies focused on natural materials as the rich source of antioxidant compounds. The aim of the present study was to evaluate some chemical properties of watermelon peel (WMP). So the minerals content, physicochemical parameters, antioxidant activity, total phenolic content, crude protein, fat, fiber, and ash determined in the WMP sample. The results showed that, watermelon peels contain protein (6.77 g/100g), fat (0.92 g/100g), ash (13.2 g/100g), fiber (24  g/100g), sodium (53.59 mg/100g), potassium (2074 mg/100g), calcium (468 mg/100g), copper (0.59 mg/100g), iron (12.08 mg/100g), magnesium (164.48 mg/100g), zinc (0.91 mg/100g) and phosphorus (107 mg/100g). It also indicates a significant free radical scavenging activity (IC50 of 147.30 mg/kg) and total phenolic content (2.47 g/100g). Finally, the WMP can consider as a good source of natural polyphenols, antioxidants and minerals.