| Tea was classified to spring and summer-autumn tea according to different acquisitiontime and fertility properties of tea. Due to different seasonal climate differences in theenvironment, as well as tea plant growth and metabolism, the spring tea contains more aromasubstances and abundant amino acid, while phenol to ammonia ratio is lower. Moreover,summer-autumn tea tastes bitter taste with lighter aroma smell. Therefore, the quality ofsummer-autumn tea is far less than spring tea.Far below the spring tea, the poor quality of summer-autumn tea determines its pooreconomic benefits, resulting in great part of fresh leaves being cut back directly for costsreduction, which causes a great waste of resources. With the promoting of Great Developmentof Western China, more tea plantations will be set up, and more summer-autumn tea resourceswill be wasted. To avoid production and marketing imbalances, transformation and upgradingof tea industry must be achieved as early as possible. And tea comprehensive processing is thetransformation and upgrading route one must take.The tea comprehensive processing mainly refers to tea production processing of fresh tealeaves, end product tea, tea scraps or defective products as raw materials, such as the effectivecomposition extraction, instant tea processing，soft drinks processing，tea-liquor processing，tea-food processing，tea-pharmaceutical processing and etc.The development of effective components extraction developed rapidly and attractedsignificant attention. Therefore, a high efficiency, low-energy-waste and green technologywill be important for functional ingredients separation and purification of tea. In this study,theanine and polyphenols are selected as research object，the summer-autumn tea as rawmaterials，to find a green, high-efficiency separation method.In order to comprehensive utilize the summer-autumn tea, the AB-8type of macroporousresin was selected and applied in the effective components extraction study of TP. And theparameters of extraction were optimized. Via static and dynamic adsorption experiment, theadsorption performance was determined. And on this basis, the Box-Behnken design was alsoapplied in establishing the mathematical model and quadratic regression equation for the TPextraction from the summer-autumn tea. And the optimized parameters were：flow rate of2.2mL/min, temperature of35℃，sample concentration of6.5mg/mL. On this condition, theadsorption rate is92.52%. In conclusion, as a high-efficiency and green extraction method,the AB-8type of macroporous resin perform well and can be used in TP extraction of the summer-autumn tea.The adsorption and desorption behavior of L-theanine with HZ-202anion exchange resinwas investigated during this study. The dynamic kinetics of HZ-202anion exchange resinwere studied, and the optimum parameters of adsorption were procured. It was shown that thepH value and concentration of L-theanine, the flow rate and temperature affected the kineticcurves of HZ-202anion exchange resin to L-theanine. Following single factor investigations,optimization of process conditions for the adsorption of free amino acid based on theadsorption rate was carried out using Box-Behnken design combined with response surfacemethodology (RSM).The optimal adsorption conditions were flow rate of4.3(BV/h), pHvalue of5.0and sample concentration of1.30(mg/mL). Under the optimal extractionconditions, a adsorption rate value of94.69%was obtained, and the relative error is1.39%ascompared to predict value. And the optimum desorption conditions were the eluent flow rate6BV/h, eluent concentration0.02mol/L. In these conditions, the adsorption rate was over98%,while desorption rate was86.22%. |
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