TPC was determined according to the method of Wang, Meckling, Marcone, Kakuda, and Tsao (2011). Briefly, tea infusion (0.02 mL) was diluted with 1.58 mL of deionized water, followed by 0.1 mL of Folin–Ciocalteu reagent. A volume of 0.3 mL of 7.5% sodium carbonate was then added. Mixture was allowed to stand at room temperature for 30 min before measuring the absorbance at 765 nm. The phenolic content was compared to a gallic acid standard curve. For CSB extract, 0.45 mL was diluted with 1.55 mL deionized water before the addition of sodium carbonate and Folin–Ciocalteu reagent. The total phenolic content of the samples was expressed as milligrams GAE per gram of sample.