Nutritional and antioxidant composition of eggplant accessions in Ghana

Abstract

Eggplants (Solanum spp.) are important vegetable crops, well known for nutritional and medicinal values of their fruits and leaves. In order to select more nutritious varieties in Ghana, 33 eggplant accessions were investigated for nutritional, mineral and antioxidant content of their fruits. Proximate and antioxidant analysis were determined by AOAC and DPPH methods. The results showed significant differences (P<0.05) among nutritional, mineral and antioxidant traits. Most accessions contained high moisture content (above 70%). Nutrient concentrations ranged from 0.10 fat to 6.10 g 100 g-1 carbohydrate; and 0.107 magnesium to 11.271 mg 100 g-1 iron. Total phenolic content was highest in accession ST004-03 (210 mg GAE g-1 (gallic acid equivalent), and lowest in SA002-02 (171.10 mg GAE g-1). Accessions ST004-02 and ST004-03 displayed the highest DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging activity (0.017 mg ml-1); while San 005-01 (1474 mg ml-1) showed the highest antioxidant content. Principal component analysis indicated that the first 3 components with Eigen value >1.5 contributed 68.68% of total variability. Dry matter, protein, moisture and carbohydrate contents showed maximum contributions to the total variability. Biplot analysis displayed strong and positive associations among ash, protein and moisture with dry matter; moisture and carbohydrate and; protein and ash. Accessions San 005-01, San 005-02, SA 002-07, SA 002-08 and ST004-03 were identified as good sources of nutrients, minerals and antioxidant properties among the others; and could be used as potential donors for hybridisation programme to develop varieties with higher concentration of these traits.

Key words: Carbohydrates, mineral, nutritional, Solanum