Extraction Of Tea Green Pigment And Effects Of It On Low Temperature Extraction Tea Juice

The tea is one of the world-famous three major beverages. With thedevelopment of tea industry, people pay more and more attention to tea deepprocessing. The researches of tea green pigment and the low temperatureextraction technology of tea are two mainly research aims. With fresh tea,enzym-denatured leaf and tea, the optimum material that was suitable forextraction of tea green pigment was selected and the optimum extractionconditions of tea green pigment was researched. The conditions of the lowtemperature extraction of tea was studied by two times general rotatory designtest. At last, the experiment that tea green pigment enhanced the quality oftea juice colourr was conducted. The results of experiments were as follows:1. Selecting the material and studing optimum extraction conditions of teagreen pigment. The results show enzym-denatured leaf was the best materialfor the extraction of tea green pigment. With enzym-denatured leaf, ethanolconcentration, ratio of ethanol to tea, extraction temperature, and time were themain factors that affected the extraction rate of tea green pigment. Theoptimum extraction conditions of tea green pigment were 100% ethanol, theratio of ethanol to tea 4.5mL:1g, the temperature 75oC and the extractionduration 25min. The extraction rate of tea green pigment was 31.50%, it wasimproved by 20.69% than the 26.1% from the past document. The tea green pigmentcontained the abundant effective components: tea polyphenols, caffeine, aminoacids etc. It was a kind of fine natural food coloring.2. The properties of tea green pigment. There were two characteristicabsorption peaks of tea green pigment at 430nm and 663nm. Tea greenpigment was stable to heat, but it was unstable to daylight, and it was stablewhen the pH of tea juice was 5⁶; effects of K⁺,Na⁺,Mg²⁺,Ca²,Zn²⁺,Cu² on the colour of tea green pigment was little, Al³⁺made tea greenpigment produce yellow deposit, and Fe²⁺,Fe³⁺made it produce dark-browndeposit immediately.3. The optimum conditions of the extraction were as follows: the...