Investigation about Various Infusion Conditions on Physical, Chemical and Antioxidant Properties of Clitoria ternatea L. Tea

Abstract

The study detected changes in some physical, chemical, and antioxidant properties of Clitoria ternatea L. teas infused at different infusion temperatures (ITE) (70 °C, 80 °C, and 90 °C) and infusion times (ITI) (9, 18, and 27 minutes) using dried flowers of particle sizes (PS) (whole and powder). The antioxidant activity was measured using DPPH, ABTS, and FRAP methods. The a*, b*, C*, and Hº values of the tea samples were found to be statistically different according to ITE, ITI, and PS (p<0.01). A significant decrease was identified in averaged a*, b*, and C* values with increasing ITE. There was a significant decrease in mean L* values of tea samples with increasing ITE (p<0.05). The total monomeric anthocyanin (TMA), total phenolic content (TPC), and antioxidant activity of tea samples differed significantly with ITE, ITI, and PS (p< 0.01). The highest TMA and TPC according to ITE (69.72 Cy-3 glu mg/L and 1000.68 mg GAE/L) in tea samples were at 90 ºC and the highest TMA and TPC according to ITI (51.54 Cy-3 glu mg/L and 918.45 mg GAE/L) were detected at 27 minutes of infused. It was determined that the TMA of the teas infused with whole flowers was higher (55.31 Cy-3 glu mg/L) than the teas infused with flower powder, and the TPC was higher (926.07 mg GAE/L) in the teas infused with the flower powder. The total flavonoid content (TFC) of the teas was determined the highest (5161.69 mg QE/L) according to ITE at 80 ºC and the highest TFC (4578.53 mg QE/L) according to ITI in 9 minutes of infused. It was observed that antioxidant activity of tea samples increased with increasing ITE and ITI. Regarding PS, it was also determined that teas brewed with flower powder showed higher antioxidant activity. According to the sensory evaluation results of tea samples, it was found that tea samples infused with whole flowers at 70 ºC for 9 minutes and tea samples infused with flower powder at 80 ºC for 27 minutes had the highest overall acceptability.