Determination of elemental, phenolic, antioxidant and flavonoid properties of Lemon grass (Cymbopogon citratus Stapf)

Commonly consumed Ghanaian lemon grass for tea making were analysed for contents of Potassium (K), Chlorine (Cl), Calcium (Ca), Magnesium (Mg) Manganese (Mn), Aluminium (Al), Copper (Cu) and Sodium (Na) across five locations using Instrumental Neutron Activation Analysis, in addition to total phenolic, antioxidant and flavonoid activities using standard methods. Potassium was the most abundance element and Cu was the least. Concentrations of these eight elements differed from location to location. Total phenolic activity in cold and hot percolations ranged from 1.3 to 4.7 mg and 2.6 to 7.3 mg of garlic acid equivalents (GAE)/g dw respectively; total antioxidant activity in cold and hot percolations ranged from 65.4 to 81.3 % and 65.4 to 81.3% respectively; and total flavonoid concentration ranged from 6.9 to 11.3 μg/g Quercetin Equivalent (QE) and 6.9 to 12.9 μg/g QE dry weight basis for cold and hot percolations respectively. The temperature of percolations therefore had pronounced effect on total phenol, antioxidant and flavonoid activities, which underscores the importance of boiling of lemongrass herbal teas to allow both simple and complex phenols to percolate faster and provide more antioxidant activities.