Effect of Different Brewing Methods on Some Physicochemical Properties of Green Tea (Camellia sinensis)

Different brewing methods can lead to changes in the physicochemical properties of green tea. In this study, the physicochemical properties of green tea brewed with different amounts (5, 7.5 and 10 grams) and times (5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 minutes) were investigated. Green tea produced by Çaykur was used in the study. Mineral analysis of green tea samples was performed with ICP-OES, and color analysis was performed with Minolta Spectrophotometer. The antioxidant activity was assessed using the DPPH method and the total phenolic content was determined using the Folin–Ciocalteu method. In terms of mineral content, it was determined highest levels of mineral content (mg/kg) for Al, Ca and Mg (10 g-25 minutes); Fe, Mn and Na (10 g-25 minutes); and B (10 g-50 minutes) as 16.005, 4.099, 24.075, 0.120, 13.855, 1.320 and 0.164, respectively. It was determined lowest levels of mineral content (mg/kg) for Al, Ca, Mg, and Mn (5 g-5 minutes); B and Fe (5 g-10 minutes), and Na (5 g-15 minutes) as 2.756, 1.193, 3.324, 1.23, 0.025, 0.002 and 0.48, respectively. In terms of color, it was determined that the lowest and highest L* values are 39.97 (10 g-45 minutes) -54.23 (5 g-35 minutes), lowest and highest a* values are -2.24 (5 g-5 minutes) (-4.70) (7.5 g-35 minutes) and lowest and highest b* values are 4.91 (5 g-5 minutes)- 23.98 (10 g-60 minutes). The antioxidant activity value (inhibition %) in green tea was found to be the range of 28.51 % (5 g, 45 minutes)- 47.95 (10 g- 40 minutes), and the total phenolic content (mg GAE/mL) was found to be the range of 15.99 (5 g, 5 minutes)- 35.61 (10 g, 15 minutes). The findings determined that green tea brewed with different amounts and times showed statistical differences in terms of color, mineral content, antioxidant activity, and total phenolic content.