Proximate analysis and antioxidant activity of watermelon rind powder

Watermelon is a summer plant and it belongs to the Cucurbit family (Citrullus lanatus). Watermelon is high in nutrients even though it is low in calories. It contains Vitamin C and Vitamin A in the form of beta — carotene which is powerful antioxidant to protect the body from free radical and fight disease. The watermelon rind has natural source of antioxidant nutrients including flavonoids, flavones and polyphenols. Therefore, this research aimed to determine the proximate analysis and to analyze antioxidant activity in the watermelon rind powder. The proximate analysis was performed to find moisture, ash, crude fat and crude protein. Then, the antioxidant activity was performed to find antioxidant activity using DPPH. The results of proximate analysis showed that the ash, moisture, crude fat and crude protein content in watermelon rind powder were 43.33 ± 19.73, 16.71 ± 0.55, 0.70 ± 0.26 and 1.89 ± 0.66 respectively. Moisture content and crude protein were significantly (p<0.05) higher than control. The result of antioxidant activity show watermelon rind powder was significant (p<0.05) higher compared to control. The result also showed the moisture content in the watermelon rind was high compared to control, thus to increase shelf life, the moisture level of the watermelon rind must be reduced. In conclusion, the watermelon rind powder was excellent source of important nutrients that may be used to enhance human diets and the antioxidant activity in watermelon rind powder has lower antioxidant in every concentration compared to control. Further studies may be performed to lower the watermelon rind powder moisture content with using osmotic dehydration machine Keyword: Watermelon, Watermelon rind, Proximate analysis, Antioxidant, Shelf life