Proximate analysis and phytochemical screening of watermelon (citrullus lanatus) pulp, peels and seeds

Abstract

The fruit popularly known as Watermelon (Citrullus lanatus) is a local recipe eaten in Nigeria and African. The research was conducted to evaluate the nutritional composition and phytoconstituents of the peels, pulp and seeds of the fruit. The vitamin C was also determined. Proximate analysis revealed that the pulp contained much higher moisture content of 11.50 ± 0.50 % than the peels with 8.78 ± 1.25 %, and 3.66±0.29 % seed respectively. The ash content for peels was high with 5.31 ± 0.55 %, while pulp contained 3.66 ± 0.82 % and the seeds contained 2.97 ± 05 % respectively. For crude lipids; seeds contained high value of 13.66 ± 0.29 % compared to the peels with 2.33 ± 0.29 % and pulp contained 0.5± 0.00 %.respectively. The crude fibre; seeds contained higher value of 14.66 ± 0.57 % compared to peels with 10.66 ± 29 % and7.66 ± 0.29 % for pulp. The crude proteins, the peels contained 2.88 ± 1.69 %, while the pulp contained 3.33± 0.17 % and seeds contained 18.75± 0.65% having the highest value which implies that the seed is rich in protein thereby help to build the body and replace worn-out tissues. The carbohydrate value for pulp was much higher with 73.35 ± 1.78 %, peels contained 70.04± 4.05 % and seed contained 46.3± 0.78 % respectively. The mineral elements revealed that Na, K, Ca, Mg, Fe, P and Zn are much present with significant different P<0.05.Therefore, seed is a reservoir of crude lipids, while pulp serves as a reservoir of moisture content and food supplement whereas peels serve as reservoir for mineral elements. The vitamin C value ranged from (4.56± 0.47 to 3.32± 0.37) mg/100 g respectively. Phytochemical analyses of aqueous extracts revealed that terpenoids, saponins, alkaloids, cardiac glycosides and steroids are present. This justify the claim why the fruit can be used as food and medicinal purpose.