Determination and analysis of main componentsof four kinds of tea and their tea wastes

With 4 kinds of tea (i.e. green tea, Ti Kwan Yin tea, black tea, Pu-er tea) as experimental materials, the contents of tea polyphenols, free amino acids and nutrient component in the tea and their tea wastes were determined by national standard method, respectively. The results showed that the content of tea polyphenols in the 4 kinds of tea wastes was 4.2%-10.1%, which was significantly lower than that in the corresponding tea (6.5%-17.8%), but which was retained more than 60% of that in the corresponding tea. Similarly, the content of free amino acids in the 4 kinds of tea wastes was 1.1%-1.4%, which was significantly lower than that in the corresponding tea (1.2%- 2.2%), and also retained more than 60% of that in the corresponding tea. However, the content of crude fiber (13.0% -19.0%) in the 4 kinds of tea wastes was significantly higher than that in the corresponding tea (10.0%-16.0%), respectively. The results of determination of nutritional ingredients showed that the content of crude protein (26.0%- 35.0%) in the 4 kinds of tea wastes was slightly higher than that in the corresponding tea (25.0%-35.0%), respectively. But the content of moisture in the 4 kinds of tea wastes (7.81%-8.82%) was significantly higher than that in the corresponding tea (4.5%-7.2%) respectively. Conversely, the content of crude fat in the 4 kinds of tea wastes (1.5%-4.5%) was significantly lower than that in the corresponding tea (4%-11%), respectively. And the content of total ash in the 4 kinds of tea wastes (3.3% -4.7%) was also significantly lower than that in the corresponding tea (5.0%-7.0%), respectively. The active and nutritional ingredients in tea wastes still contained high tea polyphenols, amino acids and main nutritional components, which could provide a theoretical basis for the development and utilization of tea wastes.