Effect of different concentrations of theaflavins and caffeine on the formation of tea cream

A model system consisting of theaflavins and caffeine was set up for studying the mechanism for the formation of tea cream in black tea. The transmittance,amount of tea cream,theaflavins and caffeine concentration of the solution were investigated to study the effects of different concentrations of theaflavins and caffeine compounds on the formation of tea cream. The results showed that the transmittance of the original solution and store solution was decreased,and the amount of precipitate was increased with adding the concentration of theaflavins and caffeine. These changing trends were more pronounced with increasing concentration of one of the two components at a constant level of the other. Sterilization didn't influence these trends. In addition,high performance liquid chromatography analysis of the concentration of caffeine and theaflavins showed that caffeine and TFDG were the main compounds forming tea cream. In order to reduce tea cream,improve the sensory evaluation of black tea beverage,and at the same time retain theaflavins concentration as much as possible,the concentration of theaflavins was less than 100mg/L and caffeine concentration was less than200mg/L when black tea raw materials were chosen to produce black tea drinks.