Bioactive constituents of waakye; a local Ghanaian dish prepared with Sorghum bicolor (L.) Moench leaf sheaths

Abstract

Rice and beans are widely consumed in most countries in the world. ‘Waakye’, a popular traditional dish widely consumed in Ghana, is prepared with Sorghum bicolor leaves to give it a distinctive colour. For the first time, the phytochemical properties of waakye prepared with Sorghum bicolor leaves are determined. Total polyphenols and flavonoid content were determined by Folin Ciocalteau and Aluminium chloride techniques respectively. The antioxidant activity of waakye was analyzed based on Ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Sorghum leaves showed high fibre (22.53%) and fat composition (8.86%). The leaves depicted high polyphenols (7.30–107.85 mg GAE/g), flavonoids (10.99–960.29 mg CE/g) and good antioxidant ability. Due perhaps to processing related losses, the polyphenols and antioxidant ability retained in the differently treated waakye products significantly reduced with exception of the waakye treated with saltpetre, which showed a higher ferric reducing ability than the aqueous extract of the leaves. Waakye (prepared with sorghum leaves) was therefore found to contain essential phytochemical constituents including antioxidants than without the sorghum leaves (control). The nutritional implication of these findings is that the consumption of waakye could be a potential cheap source of essential fatty acids, antioxidant and polyphenols which could contribute to the health and biological activities. Keywords: Bean and rice, Polyphenols, Antioxidants, Colour, Bioactive compounds