Abstract
Twenty one (21) traditional food plants recognized as medicinal by communities in Kamuli and Gulu districts in Uganda were identified and analyzed for their phytochemical content and antioxidant activity. The total phenolic content (2.6 ± 0.1 to 184.2 ± 6.4 mg GAE gDW-1) and flavonoid content (0.3 ± 0.1 to 162.2 ± 3.5 mg CE gDW-1) as well as antioxidant activity (0.1 ± 0.1 to 57.8 ± 0.5 mg VCE gDW-1) varied widely among the food plants. The seeds of Tamarindus indica L. and leaves of Ipomea eriocarpa R.Br., Corchorus trilocularis L., Ocimum suave L., Corchorus olitorius L., Acalypha bipartita Müll.Arg., and Hibiscus acetosella Welw. ex Hiern showed the highest phenolic contents and antioxidant activities. Juice prepared from tamarind pulp alone or mixed with tamarind seed powder (0.5, 1 and 3%) and analyzed for sensory acceptability, phenolic content and anti-oxidant activity were found to be highly acceptable, recording an overall hedonic acceptability scores of 7.40 ± 0.4, 6.65 ± 0.3, 7.01 ± 0.1 and 5.34 ± 0.2, respectively on a nine-point scale for juice containing 0, 0.5, 1 and 3% seed powder. Incorporation of tamarind seed powder into tamarind pulp juice resulted in a dose dependent increase in antioxidant activity from 8.5 ± 0.2 mg VCE 100 ml-1 for the control to 12.05 ± 0.3, 15.33 ± 0.7 and 17.22 ± 0.7 mg VCE 100 ml-1 for tamarind juice containing 0.5, 1 and 3% seed powder, respectively. A similar trend was recorded for the total phenolic and flavonoids.
Key words: Medicinal foods, nutraceuticals, antioxidant activity, phenolics, flavonoids.
