Kinetics of Tea Infusion. Part 2: The Effect of Tea-bag Material on the Rate and Temperature Dependence of Caffeine Extraction from Black Assam tea

Abstract

Extraction experiments of tea inside tea-bag material were carried out at different temperatures. The rates of extraction were measured for caffeine from black orthodox Assam tea into distilled water. The leaf size used was 1.18±1.40 mm and the results obtained were compared with those of loose tea. The first order rate constants for the tea-bag tea were found to be 29% smaller than those of loose tea. The activation energies were found to be 45ã2 and 43ã2 kJ molˇ1 for loose tea and tea-bag tea, respectively. These results show that the tea-bag material slows the infusion.