Polyphenols Extract New Technology Research,

On basis of the composition, structure, properties and application of Tea poly- phenols(TP) and its extracting theory , the technological process of TP extraction was investigated. (1) Technological process of extraction for TP with organic solvent was investigated; the anti-oxidation of TP was elementarily discussed also. Experimental results by HPLC and UV Spectra show: oxidation of TP in water especially catechins can be inhibited by ethanol aqueous, the extraction ratio of TP is 32.1wt% when extracting with 40vol% ethanol aqueous, three times at 40 癈, lOmin each time, EGCG, EGC, C, EC and ECG is 7.5%, 4.1%, 0.1%, 0.6% and 2.2wt% respectively. The yields of TP and catechins increases by 29.4% and 16.1wt% compared with extracts by GB8313-87. (2) Technological process of purification was completed by chromatographic column packed with 30-40 mesh polyamide. Employing 120 X 30mm column, the saturated adsorption amount determined by dynamic experiments of TP is 73.4mg/g (dry resin) , the optimum adsorption amount by adsorption-desorption experiment for TP separation is 50mg/g(dry resin); At this condition, purification was carried out first by 120ml, 5vol% ethanol aqueous at the flow rate 1 .Oml/min to elute caffeine, then pigment by 285ml 70vol% rated ethanol aqueous at 1.Oml/min. The recovery ratio of TP in the process of purification is 59.4wt% on average, and desorbing ratio of caffeine 96.3wt%. The total yields of TP is 19.2wt%( Ig dry tea leaves), the contents of catechins analyzed by HPLC in the product is 65.1wt%, in which EGCG33.3%, EGC 18.8%, ECG8.8%, EC2.6%, CO.5% and GA1.0wt% respectively, especially, the content of caffeine is as low as 1.04wt%. (3) Effects of mobile phase, acid, flow rate, pH, and injection volume on analysis of TP by High-performance Liquid Chromatograph were discussed as well. The contents of catechins of TP were determined by 250X4.6mm reversed phase column packed with 5um Cig modified silica, the analysis condition is as follows: mobile phase is aqueous rated by ethanol: water: acetic acid =25:74.5:0.5(v/v) , flow rate 1.Oml/min, temperature 30"C, injection volume 6ul, UV detector at 280nm, isocratical elution. According to these conditions, the experimental separating time is 45min; the resolution 1.46, the value of relative co-efficiency of the regression equation is 0.996 and recovery ratio 96-98wt%.