Evaluation of Antioxidant Properties and Polyphenol Content of Selected Nigerian Teas and Herbal Infusions Consumed in Bauchi State

Tea and herbal infusions are widely consumed beverages across Northern Nigeria, with consumption in Bauchi State spanning both imported commercial teas and locally prepared herbal infusions from plants such as Hibiscus sabdariffa (zobo), Zingiber officinale (ginger), and Cymbopogon citratus (lemongrass). These beverages are valued for both their taste and perceived health-promoting properties. This study evaluated and compared the total polyphenol content and antioxidant properties of six commercial tea brands and four traditional herbal infusions consumed in Bauchi State. Beverages were prepared according to standard consumer methods. Total polyphenol content was determined by the Folin-Ciocalteu method expressed as gallic acid equivalents. Antioxidant activity was measured by DPPH radical scavenging, FRAP, and ABTS radical cation decolorisation assays. Caffeine content in commercial teas was determined by UV spectrophotometry at 273 nm. Total polyphenol content ranged from 38.4 mg GAE/100 mL in the lowest commercial brand to 214.7 mg GAE/100 mL in Hibiscus sabdariffa infusion. Hibiscus infusion also showed the highest DPPH scavenging activity and FRAP value. Among commercial teas, green tea brands showed consistently higher polyphenol and antioxidant values than black tea brands. Ginger infusion showed moderate antioxidant activity with a distinct flavonoid-rich profile. These results provide comparative antioxidant data supporting the nutraceutical value of local herbal infusions as health-promoting alternatives to imported commercial teas. Keywords: polyphenols, antioxidant, herbal infusions, Hibiscus sabdariffa, Bauchi State.