Preliminary Studies On Synthesis And Purification Conditions Of Theaflanina

This article reported a new process applied bio-enzyme method that green tea p owder with low cost and high polyphenol as raw material to synthesize theaflavins, then macroporous adsorptive resin was done to purify theaflavins in earlier studies. The technological process was divided into polyphenol oxidase(PPO) selection, extra cted PPO from seven plants such as pear,apple and so on and measured their acti vity, choose the material with highest activity as the best enzyme source; the effects of different metal ions on PPO, different metal ion with different concentration wer e measured to choose activator of PPO; the selection of reaction conditions of synth esizing theaflavins, optimum synthesis condition were determined on the basis of sin gle factor and orthogonal experiments; the selection of optimum condition to purify theaflavins.(1) Pear, apple, potatoes, tea leaves, eggplant, sweet potato and lotus root seve n plants were chosen as enzyme source materials, the buffer solution method were used to extract and measure the activity of PPO. By comparing the activity of diffe rent enzyme source materials, the material with the highest activity was chosen as t he best enzyme source material for theaflavin synthesis. The PPO activity in differe nt source material was:174U in eggplant,101.43U in potato,58U in sweet potatoes, 37U in pear,32U in lotus roots,24.67U in apple,10U in tea leaves. Eggplant wa s choosen as the best enzyme source material.(2) Copper ion, manganese ion, magnesium ion, calcium ion, sodium ion,alumi num ion and ferric ion at different concentrations were added into crude eggplant P PO enzyme.The results showed that copper ion at a concentration of 3mmol/L can s ignificantly activate PPO, while calcium ion, sodium ion, aluminum ion and ferric i on inhibited the activity of PPO. Among them, ferric ion at concentration of 5mmol /L can significantly inhibit the activity of PPO, which can be inhibited 96.6% on th is condition.(3) Different synthesis conditions (pH value, temperature, concentration of subs trate, enzyme concentration and reaction time) were determined on the basis of singl e factor and orthogonal experiments. The results showed that the best conditions of reaction System were a:pH value of 4.5, temperature of 25℃, substrate concentrati on of 2.5g/L, enzyme additive amount of 35ml and a reaction time of 40min. Am ong these conditions, pH value and concentration of substrate were two the most i mportant factors in this reaction system.(4) Macroporous adsorptive resin was selected to putify theaflavins that synthesi zed on the best conditions included the type of resin, pH value, concentration of sa mple, the flow rate, the effluent volume and the concentration of effluent.The results showed that the best condition to purify the theaflavins were:pH valve of 3, samp le filling rate of 2BV/h,15% effluent of eliminating impurity volume, effluent volu me of 3 BV and an effluent concentration of 90%. pH value and sample filling rat e were two important factors in the purification system.