Optimization Of Fermentation Technology And Bioactivity Of Hawk Black Tea

Hawk tea,also known as Laoyin tea,has a variety of bioactive components and potential application prospects.In this study,Sichuan hawk tea was used as raw material to separate bioactive substances from tea from different regions,and its antibacterial and antioxidant properties were analyzed.The black tea product fermented with Shimian hawk tea as raw material was developed,and the production process was optimized,and the hypoglycemic effect of the product was studied.The main results are as follows:1.Extraction and measurement of main bioactive substances from Hawk tea.The crude extract rich in tea polyphenols and flavonoids was separated and extracted by ultrasonic assisted extraction technology,and the content of the leaves was determined by using fresh plant leaves of 3 different producing areas in Sichuan Province.The results showed that the content of tea polyphenols in 6 samples was 16.24%-22.1%,and the flavonoid content was13.84%-16.77%.The content of polyphenols and flavonoids in leaves of the fresh plants of asbestium Hawk tea was the highest among the six samples.2.Study on the antibacterial activity and antioxidant activity of the main active substances of the Hawk tea.The crude extracts of fresh plant leaves of three different areas of Aoying tea and Aoying tea were extracted by ultrasonic assisted extraction technology.The antibacterial effect on four bacteria,DPPH scavenging ability and total reduction ability were measured.The results showed that the diameter of the inhibition circle of 6 samples was0.85-2.56 cm,and the growth of four bacteria was inhibited.The higher the concentration of the extract,the stronger the bacteriostatic effect,and stronger anti-oxidation ability.The DPPH free radical scavenging ability and total reduction ability of the six samples were higher than that of the control BHT(2,6-di-tert-butyl-p-cresol).The order of antibacterial activity and antioxidant capacity was from strong to weak: fresh leaves of asbestos Hawk tea,fresh leaves of Xuzhou Hawk tea,green Sichuan Hawk tea leaves,asbestos Hawk tea,Xuzhou Hawk tea,Qingchuan Hawk tea.3.Optimization of fermentation technology of black tea.The fresh leaves of Shimian hawk tea were selected as raw materials and processed by black tea technology.The differences of sensory quality,main biochemical components and aroma components of black tea during fermentation were studied,and the effects of black tea technology on Hawk tea quality were analyzed.According to the results of sensory and physical and chemical experiments,the inoculation amount was 1.5 ml,the water content was 40%,the fermentation temperature was 30 ℃,and the fermentation days was 18 days The content of water extract decreased by 7.64%,the content of tea polyphenols decreased by 9.25%,the content of flavonoids increased by 3.6%,the content of soluble sugar increased by 1.47%,the content of theaflavins and thearubicin decreased by 0.85% and 1.85%,respectively,and the content of theabrownin increased by 6.32%.According to the experimental results of aroma analysis,the aroma of Hawk tea showed the unique aroma of Lauraceae plants,with strong irritation and poor flavor.The flavor quality of Hawk black tea was good,the characteristic pungent odor was weakened,the fresh flower aroma,fruit aroma and rosin were increased,the pleasant odor was produced,and the overall aroma was improved.4.Research on the effect of fermented black tea on lowering blood sugar.A rat type 1diabetes model was established by STZ(streptozotocin),and the effects of Hawk tea and black tea extracts on rat body weight,blood sugar,glucose tolerance and pancreatic tissue lesions were observed.The results showed that Hawk tea and dark tea had a significant inhibitory effect on the weight loss caused by diabetes.The blood sugar values of the Hawk tea group and dark tea group were reduced by 7.84% and 9.62%,respectively,indicating that the blood sugar of rats was significantly reduced.The glucose tolerance level of diabetic rats has been improved,and the secretion function of pancreatic islet cells has been significantly improved.The hypoglycemic effect of black tea was better than Hawk tea.