| Tea is one of the most famous three traditional beverages, which is an important industrial crop in the world. People all over the world like it. With the development of tea industry, people pay more and more attention to tea advanced processing. The researches of extraction and application of tea green pigment is one of main research aims. The extraction of tea green pigment enhances the income of peasant and is helpful to appreciation of tea and health of people. With fresh tea, enzym-denatured leaf and tea, the optimum material that was suitable for extraction of tea green pigment was selected and the optimum extraction conditions of tea green pigment was researched. At last, the experiment that tea green pigment enhanced the quality of tea juice colour was conducted. The results of experiments were as follows:1. Selecting of tea green pigment extracting material. The results show enzym-denatured leaf was the best material for extractiing tea green pigment. With enzym-denatured leaf, ethanol concentration, ratio of ethanol to tea, and extraction time and temperature were the four main factors that affected the extraction rate of tea green pigment.2 Optimizing extraction conditions of tea green pigment. The optimum extraction conditions of tea green pigment was A4B2C4D4, that was to say, 100% ethanol, the ratio of ethanol to tea 4.5mL:1g, the extraction temperature 75oC and the extraction duration 25min. The extraction rate of tea green pigment was 30.17%, which was improved by 15.59% compared with the 26.10% which was reported before. The tea green pigment contained abundant effective components: tea polyphenols, caffeine, amino acids etc. It was a kind of fine natural food coloring.3. Properties of tea green pigment. The tea green pigment had two characteristic absorption peaks which were at 430nm and 663nm, respectively. Tea green pigment was stable to heat, but it was unstable to daylight, and it was stable when the pH of tea juice was 5~6; adding K+,Na+,Mg2+,Ca2+,... |
PDF Full Text Request