Effects Of Aspergillus Niger Fermentation On The Main Active Substances Of Ampelopsis Grossedentata And Its Enzyme Production

Ampelopsis grossedentata,namely the tender leaves of the genus Omphitis in Vitis family,is widely distributed in Guangdong,Guangxi,Guizhou,Yunnan and other regions.It is a traditional plant used for both medicine and food.Its main active substances,flavonoids,have a variety of biological activities.In this study,Aspergillus Niger was inoculated with Ampelopsis grossedentata as the substrate.Fermentation was carried out at different fermentation temperatures,time,inoculation amount and water content.After the completion of fermentation,the content changes of total flavonoids of main active substances of Ampelopsis grossedentata and the changes of related indexes were determined,and the enzyme production of Aspergillus Niger was detected.At the same time,the orthogonal optimization method was used to optimize the fermentation conditions,in order to provide a new reference scheme for the development and utilization of camellia sinensis,and make a preliminary exploration for the feasibility of Aspergillus Niger fermentation of camellia sinensis as feed additive.The main experimental results are as follows:(1)after fermentation rattan tea flavonoids compared with unleavened rattan tea flavonoids,its content increased significantly,with ultrasonic crushing method(50% ethanol as solvent,and solid-liquid ratio1:7 0,ultrasonic broken 20 min),total flavonoids extraction and fermentation before and after fermentation cany tea with aluminium trichloride chromogenic method determination of its content,so after fermentation of the tea flavonoids content is higher than that of without fermentation rattan tea flavonoids.Under fermentation conditions of temperature 28?,moisture content of 50%,fermentation time 48 hours and inoculation amount of 5%,the total flavonoids content was the highest,which was 66.89mg/g,more than twice as high as that of33.44mg/g without fermentation.(2)The antioxidant activity of total flavonoids was significantly improved after fermentation: DPPH free radical scavenging rate and hydroxyl free radical scavenging rate were used as indexes to determine the antioxidant activity of total flavonoids before and after fermentation,and the antioxidant activity of total flavonoids after fermentation was significantly increased.The scavenging rate of DPPH and hydroxyl was56.16% and 20.35% respectively.The clearance rate of DPPH and hydroxyl group of total flavonoids in the fermented group were much higher than those in the unfermented group.The DPPH scavenging rate of the total flavonoids was the highest after fermentation with water content of 40%,temperature of 30?,inoculation amount of 5% and fermentation time of 48 h,which was up to 88.98%,32.82% higher than that of the total flavonoids of the unfermented Ampelopsis grossedentata.Under the conditions of 50% water content,30?,inoculation amount of5% and fermentation time of 36 h,the hydroxyl scavenging rate of total flavonoids was the highest,reaching 68.89%.The removal rate of hydroxyl was 48.54% higher than that of unfermented hydroxyl.(3)Aspergillus Niger production of enzymes: sodium carboxymethyl cellulose,xylan,sodium phytate as substrates;The activity of cellulase,xylanase and phytase was determined.Enzyme activity unit is defined as:at a specific temperature and p H,catalyzing the substrate to produce 1?g of product per unit time is an enzyme activity unit.The results showed that the maximum cellulase activity reached 484.52U/g when the water content was 30%,fermentation temperature was 30?,fermentation time was 48 h,and inoculation amount was 5%.The maximum activity of xylanase and phytase was 223.47 U/g and 287.20U/g,respectively,when the water content was 50%,fermentation temperature was 30 ?,fermentation time was 48 h,and inoculation amount was 5%.