The Thechnology Of Separating And Purificating The Tea Polyphend Monomer From Waste Tea

A new technics of extraction and separation was adopted in the experiment,and improved and innovated the extraction and purification process on basis of traditional tea polyhenols extracting technology.The southern shaanxi tea scrap was used as the raw materials in the experiment.There are two new technologies of ultrasonic extraction and coupled ultrasonic wave and vacuum extraction used to effectively strengthen polyhenols extracting.Furthermore,macroporous absorption resin was used to purify the two kind of ester catehchin monomers,and EGCG and ECG products of high content can be obtain by silica column chromatography.1.The optimum process of ultrasonic extractionThe southern shaanxi tea scrap was used as the raw materials.To optimize the ultrasonic extraction of tea polyphenols from tea scrap,the response surface methodology with four factors at three levels was adopted,and the factors influencing the process parameters were determined by regression analysis.The results showed that the optimum conditions for the ultrasonic extraction were as follows:extracting time=25min,ultrasonic power=350W,alcohol concentration=68%,extracting temperature=70℃,repeating the validation in 5 times,and the extraction yield of tea-polyphenols from tea scrap=22.36%,the experiment results was coincident with the prediction of 22.92%.2.The optimum process of coupled ultrasonic wave and vacuum extractionThe southern shaanxi tea scrap was used as the raw materials.To optimize the ultrasonic extraction of tea polyphenols from tea scrap,the response surface methodology with three factors at three levels was adopted,and the factors influencing the process parameters were determined by regression analysis.The results showed that the optimum conditions for the ultrasonic extraction were as follows:extracting time=13min,alcohol concentration=65%,extracting temperature=65℃,repeating the validation in 5 times,and the extraction yield of tea-polyphenols from tea scrap=22.44%,the experiment results was coincident with the prediction of 23.49%.3.adsorption and desorption experiment of the tea-polyphenolsIn the resin static adsorption experiment,we selected eight kinds of macroporous absorption resins with different polarity and finally screened the resin DM-130 for the further dynamic adsorption test.The adsorption conditions(maximum saturation adsorption quantity,absorption velocity,ratio of height to diameter)and analytical conditions(elution velocity,ratio of height to diameter,least to the pulse volume)were confirmed.Desorpting via the water,10%ethanol,50%ethanol solution and then using the rotary evaporation to remove the ethanol solution,two kinds of tea polyphenols monomer material were got.HPLC and LC/MS identified as EGCG and ECG.The content of ECG were 79.15%and the content of EGCG were 69.97%.Based on the experimental data,by comparing the other Extraction Methods,combination of ultrasonic wave technology and vacuum extraction technology to extract tea-polyphenols is determined the best extraction method and provides new reference for extracting technology development.The process for extracting and purifying EGCG and ECG is simple,easy to control,low cost and high yield,also the reusable ethanol solvent will be reuse.The routing can be used in the industrial production in the future.