Functional Properties of Fruits of Selected Five Solanum Species in Sri Lanka

Abstract

Solanaceae is an economically and medicinally important family consisting of many species. The fruits of Solanum spp. have a significantly high number of secondary metabolites. Therefore, used in the treatment of numerous ailments and it has a lot of attention as a functional food. The present study aims to determine the total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) of fruits of five selected Solanum spp. namely; Solanum melongena (brinjal), Solanum torvum (thibbatu), Solanum violaceum (thiththa thibbatu), Solanum insanum (prickly calyx; local elabatu) and Solanum insanum (non-prickly calyx; thai elabatu) in Sri Lanka. Homogenous, representative fresh samples in the harvesting stage were collected from home gardens situated in North Western and Southern Provinces in Sri Lanka. TPC, TFC and TAC were determined using the Folin-Ciocalteu method, colorimetric method and ferric-reducing antioxidant power (FRAP) assay respectively. Data were analyzed using analysis of variance (ANOVA) followed by the Turkey Multiple Range Test using SAS. Solanum torvum was reported the significantly higher TPC (13.17 ± 0.23 mg GAE /g DW), TFC (51.96 ± 1.34 mg RE /g DW) and TAC (20.05 ± 1.83 mg TE / g DW). Other selected species were recorded  TPC, TFC and TAC as Solanum melongena with seeds (12.17 ± 0.47 mg GAE /g DW, 35.74 ± 0.95 mg RE /g DW, 10.78 ± 1.14 mg TE / g DW), Solanum violaceum with seeds (5.27 ± 0.34 mg GAE /g DW, 8.63 ± 1.07 mg RE /g DW, 6.03 ± 0.63 mg TE / g DW), the flesh of Solanum insanum (prickly calyx) (5.07 ± 0.30 mg GAE /g DW, 10.63 ± 2.00 mg RE /g DW, 5.24 ± 0.33 mg TE / g DW), Solanum insanum (prickly calyx) with seeds (8.68 ± 0.30 mg GAE /g DW, 17.74 ± 1.84 mg RE /g DW, 9.69 ± 0.81 mg TE / g DW), the flesh of Solanum insanum (non-prickly calyx) (6.32 ± 0.63 mg GAE /g DW, 14.18 ± 1.59 mg RE /g DW, 5.86 ± 0.37 mg TE / g DW ) and Solanum insanum (non-prickly calyx) with seeds (11.08 ± 0.93 mg GAE /g DW, 32.96 ± 2.00 mg RE /g DW, 11.10 ± 3.34 mg TE / g DW) respectively. Moreover, this study showed positive correlations of TAC with TPC (R² = 0.7699) and TFC (R² = 0.8935). The results of the present study concluded that fruits of all selected Solanum species exhibited a marked amount of bioactive compounds and antioxidant capacity.