Studies On The Dynamic Changes Of The Main Quality Components In Green Tea During Brewing And The Correlation Between The Components And The Organolepeic Evaluation

In this paper we describe the dynamic changes of some quality-related components in green tea during brewing. In addition, the correlation between the chemical compositions of green tea and the organolepeic evaluation was analyzed.The effects of temperature on the amount water-extracted tea polyphenols, caffeine, and amino acid are that with the increasing of water temperature, the water-extracted increase logarithmic linearly. The regression equation between the water-extracted tea polyphenols in green tea soup and temperature is: Y=137.130Ln(X)-465.540(R=0.981**).The regression equation between the water-extracted amino acid and temperature is: Y=21.827Ln(X)-68.004(R=0.98r*). The regression equation between the water-extracted caffeine and temperature is: Y=25.236Ln(X)-83.942(R=0.985**).The brewing tune also affected the infusion efficiency. But with further brewing, about 25min later, they declined again. On the other hand, amino acid could continually transfer to tea solution; only with time, the infusion rate became slower. The regression equation between the water-extracted amino acid and brewing time is: Y=7.504Ln(X)+18.708,(R=0.993**).The water-extracted tea polyphenols and caffeine don't correlate with brewing time.The water-extracted tea polyphenols in green tea soup were raised with the more brewing water used. The water-extracted tea polyphenols correlated with tea-water proportion. The regression equation between the water-extracted tea polyphenols and tea-water proportion is: Y=1.117X+89.262(R=0.987").The effects of brewing water on the water-extracted amino acid were that with the more brewing water used, the water-extracted amino acid were raised, and to highest levels when the tea-waterproportion is 3g - 200ml.The amount of brewing water could raise the water-extracted caffeine in green tea soup. The regression equation between the water-extracted caffeine and tea-water proportion is: Y=0.051X+40.579,(R=0.993**).The average diffusing velocities of the main quality components in green tea soup under various brewing temperature were raised with the temperature increased. With the increased of water temperature the average diffusing velocities increased logarithmic linearly. The regression equation between the average diffusing velocities of tea polyphenols in green tea soup and temperature is: Y=41.319Ln(X)-139.660 (R=0.981**). The regression equation between the average diffusing velocities of amino acid in green tea soup and temperature is : Y=6.549Ln(X)-20.404(R=0.98f *). The regression equation between the average diffusing velocities of caffeine in green tea soup and temperature is: Y=7.571Ln(X)-25.182(R=0.985**). The average diffusing velocities of the chemical components didn't increase same when brewing temperature increased 10癈.The diffusing velocities of tea polyphenols increased quickly from 60 癈 to70癈 and from 70 癈 to 80 癈.It could be increased by 24.48% and 20.79%. The infusion rate became slower with the brewing temperature increased. The diffusing velocities of amino acid in green tea soup increased quickly from 70癈 to 80癈 and from 80癈 to 90癈. It could be increased by 15.77% and 14.14%.The diffusing velocities of caffeine increased quickly from 70 癈 to 80 癈.With the increasing of brewing time, the average diffusing velocities of the main quality components increased linearly. We put forward a regression equation between the average diffusing velocities of tea polyphemols and brewing time: Y=145.070X~?08 (0.998**),a regression equation between the average diffusing velocities of amino acid and brewing time: Y=26.351X~?09(R=0.996**) and a regression equation between the average diffusing velocities of caffeine and brewing time: Y=28.457X~?726(R=0.994**).The diffusing velocities of the main quality components were not same in each period. With further brewing, the diffusing velocities of tea polyphenols, caffeine, and amino acid decreased. The diffusingvelocities reached maximum in the first minute. With further brewing, they declined q...