Kinetics of tea infusion. Part 2: the effect of tea-bag materia1 on the rate and temperature dependence of caffeine extraction from black Assam tea

摘要

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 l.l8-l.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 29/100 smaller than those of loose tea. The activation energies were found to be 45±2 and 43 ±2 kJ mo1~-l for 1oose tea and tea-bag tea, respectively. These results show that the tea-bag material slows the infusion.