Evaluation of proximate and antioxidant activities of Ethiopian eggplant (Solanum aethiopicum L) and Gboma Eggplant (Solanum macrocarpon L)

Abstract

There are over 25 species of egg plants in Nigeria including those domesticated for their leaves, fruits or both; eaten as vegetables or used in traditional medicine. However, S. aethiopicum and S. macrocarpum are the most cultivated and most utilized in Nigeria. Nutritional composition, phytochemical screening and antioxidant activity of S. aethiopicum and S. macrocarpon were studied. The moisture, crude protein, crude fat and crude fibre contents were 91.20 ± 0.34, 1.07 ± 0.01, 0.38 ± 0.03 and 2.44 ± 0.04% for S. aethiopicum while those of S. macrocarpon were 92.00 ± 0.43, 0.52 ± 0.02, 0.15 ± 0.02 and 2.50 ± 0.02%. The results revealed that the S. aethiopicum specie has higher nutritional values than the S. macrocarpon specie. Alkaloids, tannins, saponins, flavonoids, terpenoids and cardiac glycosides are present in the species at different levels. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) quantitative antioxidant analysis confirmed this. The extracts of the S. macrocarpon specie has a higher DPPH scavenging activity with a lower IC₅₀ value of 33.56 μg/ml compared to the extracts of S. aethiopicum specie with IC₅₀ of 38.92 μg/ml. The experimental results have revealed that the two species of African eggplant are nutritionally and therapeutically valuable and can be developed as functional foods having both nutritional and medicinal benefits to consumers.

Keywords: Solanum aethiopicum, Solanum macrocarpon, phytochemical screening, antioxidant, DPPH