Patent ID: 7879371

Claim:
A method of preparing a thermolabile caffeine fraction from tea leaves of a tea plant, said method comprising the steps of: a. extracting dried tea leaves overnight at room temperature with about 10-40% aqueous acetone to obtain an aqueous acetone extract; b. extracting the aqueous acetone extract of step (a) with n-hexane to obtain an aqueous acetone layer and a hexane layer; c. extracting the aqueous acetone layer of step (b) with petroleum ether and ethyl acetate to remove catechins from the aqueous acetone layer; d. extracting the aqueous acetone layer of step (c) with chloroform to obtain a chloroform layer containing caffeine; e. concentrating the chloroform layer to obtain a caffeine fraction and estimating total caffeine in the caffeine fraction; and f. sterilizing the caffeine fraction both by autoclaving and filter sterilization to obtain said thermolabile caffeine fraction.