Study On The Processing Technology And Quality Of Lotus Leaf Tea

The lotus leaf contains a variety of active ingredients, such as flavonoids, alkaloid, volatile oil, organic acid, Vitamin C, ?-Carotene, sterides and saponin, which have the effect of lipid regulation to lose weight, reducing blood press, oxidation resistance, inhibition of hypercholesterolemia and atherosclerosis, bacteriostat and antispasmodic. And the resource of lotus leaf is abundant and widely and the price is low, therefore the lotus leaf tea has a broad development prospect.There are not many kinds of leaf tea drinks on the market at present and the drinks are mostly packaged in bags or bottles. The preliminary working of the lotus leaf is mainly dried directly or employs the technique like part of the green tea process. The flavor of lotus leaf is not good and part of the products has off-flavor, which having the health and safety issues. Therefore, combining the clean production technology to optimize the processing technic and technical parameters in each process of the lotus leaf tea systematically to improve the flavor of the tea and improve its nutritional value is the current problem needs to be solved urgently.The tea processing theory and technology is used for reference in this thesis and the lotus leaf in different periods is taken for raw material to study the impact of different processing technic and main technical parameters on the quality of the lotus leaf tea to determine the suitable season for collecting and processing the tea and the treatment of its appearance. The main result of the study is as follows:(1) The processing technic of the green tea is more suitable for the process of the lotus leaf tea. The fragrance of the processed lotus leaf tea product is rich and lasting, the liquor color is yellow (green) and clear and the taste is fresh and sweet, having the feature of the famous quality green tea.(2) To scatter (lightly wither) the lotus leaf tea modestly is in favor of the formation of the good quality of the tea. Within a certain period of time, short-time scattering of the lotus leaf tea can make the tea fresh while the long-time scattering can make the tea sweeter. Under the environment conditions of this test, the lotus leaf tea which is scattered in 2h and the water content is 78% has the good sensory and biochemical quality. The state of the lotus leaf which reaches the best scattering time is:the leaf is dark green, the greenness is weakened, the fragrance comes up, the leaf is soft and the edge of the leaf is curly.(3) The best method of de-enzyme is the microwave de-enzyme, the following is the steam de-enzyme. The leaf treated through microwave de-enzyme is green and more fresh and has the bean fragrance. The content of soluble sugar is 45% higher than that of steam de-enzyme. Within certain limits, the longer the microwave treatment is, the content of aqueous extract, soluble sugar and flavonoid is higher, but the evaluation score for the sense is lower.(4) The short-time rolling (or no rolling) is more conducive to the formation of lotus leaf tea quality. The long-time rolling influences the sensory and biochemical quality and makes it lower though it is favor of the formation of the tea. The mould can be used to cut the leaf into beautiful shape for the non-rolling lotus leaf tea. The short-time rolling tea can be processed into the tea bag to solve the problem of coarse and loose shape which is not beautiful.(5) Baking temperature of lotus leaf tea should not be used for a long time,100? bake 1 hour is better.The tea made in June to August has insignificant difference in the quality. Comparatively speaking, the lotus leaf tea made in July is better.