Study On The Preparation Technology Of Tea Polyphenol And Its Modification

In my work, we prepared tea polyphenols (TP)with green tea scraps or coarse tea as raw materials by ion complexing method. After purifying the products by column chromatography, we modified the tea polyphenol and characterized by IR spectra. The main conclusions are as follow:1. After analyzing by single factor experiment, central composite design and response surface, the influence factors of Zn-TP complex are the amount of precipitant, pH value, settling time, and temperature. The optimize conditions:Zn:TP=3:1 (mol: mol), settling time=30 min, temperature=30℃, pH=6.3. The precipitation of TP is up to 93.95% in this condition. The IR spectra demonstrates Zn2+and TP have a good complexation. The Atomic absorption spectra shows the content of Zn is 9.3%, and TP is 90.19%. The results are the same to the optimize values by central composite design.2. We choose polyamide resin as filler in the column. The influence of ethanol concentration, the amount of samples, elution volume and flow velocity were investigated. The results show 7 g TP was absorbed by 104 mg polyamide resin in the flow velocity of 2 BV/h. Respectively, CAF and EGC can be washed by 10% and 10-40% ethanol.3. TP modified by oleoyl chloride is pale yellow powder. The polyphenol content of TP is 97.1%, which is much higher than that of modified TP (35.62%).The TP and modified TP were characterized by IR spectra. Result shows oleoyl was successfully modified to TP.4. We also research the oxidation resistance of modified TP. The results demonstrate the oxidation resistance improve obviously by increasing the adding amount of modified TP. Moreover, it can effectively prolong oxidation induction period of oil. The modified TP is attractive in the fields of food and medicine.