Study On The Effective Components Of Artificial Inoculation Of Fermented Mulberry Leaf Tea And Its Effect On Lipid Lowering In Mice

Mulberry leaves are medicinal and edible herbs,containing various chemical components such as flavonoids and amino acids,which have functional benefits such as lowering blood pressure,anti-oxidation,and anti-virus on the human body.my country is rich in mulberry leaf resources.In addition to fresh food,it is often processed into mulberry leaf green tea.Therefore,on the basis of the production of mulberry leaf green tea,further fermentation was carried out:that is,microwave sterilization was used,water was added to soften mulberry leaf green tea,and then pure Aspergillus niger was inoculated to prepare fermented mulberry leaf tea,and its fermentation process was carried out.Optimization was carried out,and at the same time,the content of total flavonoids,total polysaccharides,polyphenols,free amino acids,rutin,quercetin,1-DNJ and antioxidants in fresh mulberry leaves,mulberry leaf green tea and fermented mulberry leaf tea were determined and analyzed.Finally,the prepared fermented mulberry leaf tea was fed to high-fat mice,and the lipid-lowering function of fermented mulberry leaf tea was studied in depth,in order to enrich the types of functional tea products,make full use of mulberry leaf resources,and meet people’s urgent needs for health,providing a theoretical basis.The specific test methods and results are as follows:1.First,under the condition of 400 W,60 s microwave,sterilize the mulberry leaf green tea sample with 5%water content.According to the tea sensory evaluation method,three factors of fermentation time（t）,fermentation temperature（℃）and inoculum amount（%）were selected for single factor test.The best process results of fermented mulberry leaf tea were obtained:the fermentation time was 5.68 d,the fermentation temperature was 30.08℃,and the inoculum amount was 16.55%.2.Through the determination and analysis of the content of bioactive components in fresh mulberry leaves,mulberry leaf green tea and fermented mulberry leaf tea boiling water extract,it was found that the content of total flavonoids in fermented mulberry leaf tea was14.71±0.21 mg/g,and the content of total polysaccharides was 14.71±0.21 mg/g.was25.17±0.30 mg/g,the polyphenol content was 2.13±0.22 mg/g,the free amino acid content was 16.45±0.26 mg/g,the rutin content was 0.96±0.25 mg/g,and the quercetin content was0.037±0.002 mg/g,the content of deoxynojirimycin（1-DNJ）was 2.19±0.36 mg/g.The content of bioactive ingredients in bisangye green tea increased by 14.40%12.68%2.67%3.47%81.88%24.98%,but the content of deoxynojirimycin（1-DNJ）decreased by 15.65%.Theofulin was only detected in fermented mulberry leaf tea,and its content was 7.55%±0.37,and the highest content of water extract was 47.30%±1.89.3.By comparing the antioxidant properties of bioactive components in fresh mulberry leaves,mulberry leaf green tea and fermented mulberry leaf tea boiling water extract,the superoxide radical scavenging ability is:fermented mulberry leaf tea>mulberry leaf green tea>fresh Mulberry leaves;the three have weak DPPH free radical scavenging ability and Fe²⁺chelation ability,and the scavenging ability is positively correlated with the tea concentration;the scavenging rate of hydroxyl free radicals is as follows:fresh mulberry leaves>fermented mulberry leaf tea>mulberry leaves Green tea;the reducing power of fresh mulberry leaves is slightly higher than that of fermented mulberry leaf tea,and is similar to that of vitamin C.4.Feeding high-fat mice with fermented mulberry leaf tea,it was found that fermented mulberry leaf tea could regulate the accumulation of fat in mice to a certain extent,increase the body length of mice,and promote the growth and development of mice.Triglyceride（TG）,total cholesterol（TC）and low-density lipoprotein（LDL-C）in serum,liver and feces of mice were measured.Alanine aminotransferase（ALT）and aspartate aminotransferase（AST）total bile acid（TBA）index content and liver tissue morphology of mice showed that serum TG TC LDL-C ALT AST content of mice fed with fermented mulberry leaf tea decreased by19.93%,30.12%,41.89%,18.24%,respectively 16.73%,high density lipoprotein HDL-C content increased by 36.96%;The content of TG TC LDL-C ALT AST in liver of mice fed with fermented mulberry leaf tea decreased by 28.41%,35.52%,30.19%,17.28%,8.93%,respectively.At the same time,TG TC content and bile acid（TBA）content in feces of mice fed with fermented mulberry leaf tea increased by 25.00%and 32.81%respectively.Through the morphology of liver tissue,it was found that the damaged liver of mice fed with fermented mulberry leaf tea was well repaired.Through the comparison of the contents of bioactive components in fresh mulberry leaves,mulberry leaf green tea and fermented mulberry leaf tea,as well as the research on the antioxidant and lipid-lowering functions of bioactive components,it was found that fermented mulberry leaf tea not only improved the flavor of mulberry leaves,color,and increased the content of bioactive components with antioxidant and lipid-lowering functions,further improving the added value of mulberry leaf products,and providing new ideas for innovative mulberry leaf products.