Evaluation of the antioxidant capacity and content of polyphenols obtained from tea (Camellia sinensis) of four brands sold in Colombia by extraction at room temperature

Herbal medicines have long been used to treat chronic diseases such as cancer, neurodegeneration and diabetes, usually in the form of herbal teas, also called tisanes. Tea, second only to water, is the most highly consumed beverage worldwide and its medicinal and health properties, long known to early Chinese civilizations, have been widely explored. The consumption of green tea in Colombia is a recent trend and the market is continuously growing, then the most common commercially available types of green tea were tested in this study; Oriental, Lipton, Hindú and Jaibel. The main objective of this study was to determine and compare the amount of polyphe-nols present in tea samples considering extraction in water at room temperature and stirring every 30 seconds for 5 minutes. The antioxidant capacity was determined by the 1,1- diphenyl-2-picrylhydrazyl (DPPH) free-radical scav-enging assay and the oxygen radical absorbance capacity (ORAC) assay. Concentrations ranging from 22.36 ± 0.98 to 41.29 ± 0.86 mg Trolox equivalent / g dry sample for DPPH assay and 22.95 ± 1.31 to 46.25 ± 2.05 mg Trolox equiv-alent / g dry simple were determined for ORAC assay. It was also found that the amount of total phenols in tea samples ranging from 2.53 ± 0.25 to 14.63 ± 0.53 mg gallic acid equivalent (GAE) / g dry sample and total flavonoid content concentration was obtained from 2.67 ± 0.20 to 7.08 ± 0.38 mg catechin equivalent / g dry simple. The antioxidant activity and total flavonoid content were highly correlated for both DPPH (r2= 0.9911) as ORAC (r2 = 0.9968). Tea extracts from the Oriental brand had the highest polyphenol content showing greater biological ac-tivity, contrary to Jaibel tea brand which recorded the lowest concentrations in all analyzes