| Tea is usually comprehensively processed by centrifugal clarification, solvent separation,column purification,vacuum concentration and so on, which result in shortages of product of low clarity,poorly cold water solubility,low yield,high cost and heavy pollution because of low efficiency of centrifuge,lose or change of hot sensitive ingredients,poor selectivity of solvent and its low recovery rate.Membrane technology has been becoming a kind of greenish and energy-saving technology in clarification,separation and concentration. Membrane filtration process has been deepgoing studied in theory and experiment,but most physical and chemical models for charactering membrane filtration process are often limited in simple liquor system with only one or two kinds of component and very low concentration, which do not suit to liquor system of current plant comprehensive processing with many components and 2% over concentration. There are some application of membrane technology on tea comprehensive processing. However, they not only could not pay attention to the membrane filtration process and the liquor quality or the yield rate,but also mostly rested on the caked filtration method of plated membrane in laboratory.Under the background of present applied technology for tea comprehensive processing and under the target to develop tea concentrated liquor, de-bitter instant tea, EGCG, theanine and theaflavin with high quality by industrialization of membrane filtration clarification, separation and concentration, the experiments of pilot-scaled micro-filtration for clarification, ultra- filtration for separation, nano-filtration or omosis filtration for concentration are carried out for different kinds of tea liquid system based on the comparative study of membrane filtration with traditional clarification, separation and concentration method. Through the analysis of regression, the mathematical models that can pay attention to both the membrane filtration process and the liquor quality is established, which can provide a set of theoretic method to screen the optimizal membrane and its operating parameters for tea comprehensive processing. Meanwhile, based on the status of membrane pollution by clarification, separation, concentration and rejected character for active ingredients in tea, high performance regeneration method for polluted membrane and technical measure to enhance the yield rate and to lighten membrane pollution were established by using external enzyme during membrane filtration processing. It provides theoretic basis and technical platform to develop tea concentrated extracts with high quality and high yield by membrane technology in tea comprehensive processing. The high performance membrane theory and technology was applied the industrial production of de-bitter instant tea, EGCG, L-theanine and theaflavins for the first time.Micro-filtrated clarification Comparative study of different clarification methods show that micro-filtration is significantly prior to natural paper filtration, paper filtration with vacuum system and centrifuge filtration. Moreover, the good clarificationcan be obtained by the processing of 0.2 n m micro-filtration under the conditions of 45 C, 0.28MPa and 2 times dialysis while the filtrated liquor is 90% of the original liquor and the weight of each dialytic water is 15% of the original liquor. By using the regression analysis of micro-filtration temperature(T),averaged pressure( A P),membrane aperture(M) and filtrated time(t) to micro-filtration flux (J) of 0.05 M m,0.2 um,0.8 um membrane ,the regression equation before dialysis has been established, which is J=92.03002+ 0.087377T+110.0528AP+10.01056M-0.3256t. Through the regression analysis of T, A P, M to the quality index of Y, the regression equation of quality index has also been established, which is Y=26.63409-0.10087T+12.45306 A P-3.67115M. Micro-filtration efficiency of different module shows that united module with shorter membrane pipe can enhance micro-filtration efficiency. The regeneration results of polluted...
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