Chemical and Antioxidant Evaluation of Star Apple Fruit (Chrysophyllum albidum) Crude Extracts
The physicochemical, antioxidant properties, vitamins and minerals composition of star apple fruit (Chrysophyllum albidum) a seasonal tropical rainforest tree  were analyzed  and revealed the proximate composition as moisture (48.38 and 47.02%), crude protein (2.75 and 2.68%), carbohydrate (24.26 and 25.17%), ash (4.175 and 4.68%), crude fat (10.94 and 10.79%) and energy value (206.50 and 208.53 Kcal) for ethanolic and aqueous extract. 100 g mineral composition (mg) of the fruit contains sodium (123.05), iron (42.45), zinc (34.45), magnesium (34.05), calcium (24.55), manganese (4.1) and potassium (2.05). The vitamins analyzed in mg/100 g indicated vitamin K (35.36), vitamin (0.124), vitamin B1 (18.68), folate (2.02), vitamin C (3.084) and vitamin B6 (3.26). Tannins, phenols, flavonoids, cardiac glycosides, terpenoids, reducing sugar and phlobatannins were present in both extracts. Saponins, steroids and alkaloid only, were present in the aqueous extract. Anthraquinone was absent in both extracts. Ethanolic extract measured by percentage inhibition of DPPH scavenging activity, scavenged more free radicals compared to the aqueous extract. Reducing power increased remarkably at 75 µg/mL in the extracts. The ethanolic extract showed more reducing power than the aqueous at equal concentrations though significantly lower than the standard at that concentration (figure 1). Nitric oxide showed significant increase in the scavenging activity of the ethanolic extract at 75 µg/mL at p < 0.05 while there was a significant decrease in the scavenging activity of the aqueous extract. The ethanolic extract showed greater scavenging activity at all concentrations than the aqueous extract.
Acknowledgements: Thanks go to Adenekan, SO Technologist Department of Biochemistry, University of Lagos for the laboratory. Partial support for this work was provided by Elder and Mrs. Urua E and Dr. and Mrs. Urua I, is gratefully acknowledged. References:  Okoli BJ, Okere OS (2010) Trans campus J Res in Nat Dev, 8(1): 1.  William H (2000) Official methods of Analysis of AOAC International. 17th ed. Gaithersburg, MD, USA, Official method, 999.11.