Estimation of some phytoconstituents in the aqueous extract of the endocarp, seeds and exocarp of watermelon (Citrullus lanatus) fruit

Abstract

Watermelon (Citrullus lanatus) is an indigenous fruit consumed in Nigeria and the world over. This study was aimed at comparatively evaluating phytoconstituents in the endocarp, seeds and exocarp of this fruit. Phytochemical tests revealed that, terpenoids, flavonoids and saponins were significantly (p<0.05) higher in the endocarp, whereas, alkaloids, total phenols, cyanogenic glycosides and anthraquinones were significantly (p<0.05) higher in the exocarp. Proximate analysis revealed that crude lipids and proteins were significantly (p<0.05) higher in the seeds; crude fibre and ash significantly (p<0.05) higher in the exocarp, while the moisture and carbohydrates were significantly (p<0.05) higher in the endocarp. Minerals like phosphorus, magnesium, chloride, iron, calcium and potassium were significantly (p<0.05) higher in the exocarp while sodium and iron were significantly (p<0.05) higher in the endocarp. The entire fruit may be consumed since every part had phytoconstituents of medicinal relevance; instead of the common practice of discarding the exocarp and seeds.