The Effect of Tea Additives and Decoction Time on the Antioxidant Activity of Traditional Libyan Tea

Aims: This study is intended to determine the effect of tea additives and decoction time on the antioxidant activity of red tea. 
Study Design: Department of Pharmacognosy, Faculty of Pharmacy, University of Tripoli 
Methodology: Tea additives that have been selected in this study were geranium, spearmint, peanut, and table sugar.  The extraction method (preparation of aqueous individual extract and poly-extract combination) was applied to mimic the Libyan folk method of tea preparation.  Using the decoction method, each individual red tea was boiled for 10, 20, and 30 mins to study the effect of decoction time.  An in-vitro analysis of antioxidant activity was applied using quantitative DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity.  
Results: Compared to the red tea, each extract has exhibited a significant increase in antioxidant activity (P < 0.05) except spearmint and table sugar.  Superior antioxidant activity was observed in the individual extracts of geranium and peanuts. In this work, the decoction time (20, 30 min) showed a decrease in the antioxidant activity in comparison to the decoction time (10 min). 
Conclusion: The poly-extract combinations were statistically significantly superior in antioxidant activity than the individual red tea.  Moreover, decoction time might influence the antioxidant activity of red tea.