Abstract: The extactrion of tea-polyphenols from tea leaves by using the ultrahigh pressure extraction technology (UPE) was studied. The experiment was designed with orthogonal method, and the yield of tea-polyphenols is used as the testing index. The extract conditions, including of the solvent concentration, pressure, the holding time of pressure and the soaking time before extraction, were investigated. The optimum extraction conditions are as follow, 60% ethanol, 200βMPa holding 3βmin., soaking 0.5 hr. The yield of tea-polyphenols is 28.92% under the optimum extraction condition. After separation, the yield of crude product of tea extraction is higher 25.3% than that of heat reflux method and the total of tea-polyphenols is higher 32% than that of heat reflux method. In addition, the extraction liquid of UPE is clear, easily to filter and no turbid after stored a long time. As a new extraction technology, UPE showed the great economic benefit if applied to extract tea-ployphenols from tea leaves in industrial scale.

Key words: tea leaves, tea polyphenols, ultrahigh pressure