Characterization of bitter leaf (<i>Vernonia amygdalina</i> Delile) extract, lemon (<i>Citrus limon</i> Osbeck), and honey in functional beverages making

Bitter leaves ( Vernonia amygdalina ) are renowned for their health benefits, largely attributed to their polyphenol and flavonoid content, which contribute to their antioxidant properties. Traditionally, these leaves are consumed as a decoction to treat fever. In this study, the antioxidant compounds of bitter leaves were extracted using three different solvents—ethanol, ethyl acetate, and hexane—through maceration for 1, 2, and 3 days. The ethanol extract obtained after 2 days of maceration was selected for further analysis. To mitigate the inherent bitterness of bitter leaves ( Vernonia amygdalina ), complementary flavors and sweeteners such as lemon and honey were incorporated. The objective was to develop a functional beverage that is both palatable and retains antioxidant activity. Combinations of 5, 10, and 15 mL of 0.5% bitter leaf extract were mixed with lemon and honey ratios of 1:1, 1:3, and 1:5. The beverages were analyzed for their antioxidant activity, physicochemical characteristics (pH, color, total titratable acidity, and total soluble solids), and sensory properties through hedonic analysis. The selected formulation was the beverage with a lemon and honey ratio of 1:1 and 10 mL of bitter leaf extract, which exhibited an IC 50 of 7.91%, total phenolic content of 13.11 mg GAE/100 mL, and total flavonoid content of 2.90 mg QE/100 mL. This study highlights the potential of utilizing local plants like Vernonia amygdalina in product development, which can contribute to the diversification of the beverage industry and support the use of indigenous resources.