Preparation And Quality Analysis Of Acanthopanax Senticosus Tea Fermented By Eurotium Cristatum

Acanthopanax senticosus as the unique Chinese herbal medicine in northern China,the work aims to improve the flavor and the utilization rate of Acanthopanax senticosus resources,the fresh leaves of Acanthopanax senticosus were made into fermented-tea by solid state fermentation with Eurotium cristatum which provided theoretical basis for the production and application of fermented-tea of Acanthopanax senticosus.The main conclusions are as follows:1.In the prior research,the strains of Eurotium cristatum was extracted,purified and identified,and the results showed that the strain was Eurotium cristatum,and then the fermentation experiments was carried out.Acanthopanax sentieosus fresh leaf was used as the experimental material to made into tea,Eurotium cristatum was used as the starter culture to fermentation the Acanthopanax sentieosus tea.The optimum fermentation conditions were determined by single factor test,and the fermentation technique was optimized by orthogonal array.The results showed that the best fermentation conditions were fermentation temperature 28?,fermentation time 8 d,and inoculation quantity 35%,under these conditions,the sensory score of fermented-tea is91.10.The best fermentation conditions of fermented tea were obtained by single factor and orthogonal design method,the sensory quality of fermented tea was improved,to provide experimental basis for measuring the main active components and flavor changes of fermented tea.2.The fermented tea of the postoptimality was used as raw material,the variations of main quality components and enzymatic activity were examined during the fermentation process.The results showed that tea polyphenols,amino acid,soluble sugar and water extract were decreased from 16.36%,4.33%,1.96%,25.39%,22.67 to 5.42%,1.34%,0.88%,21.96%,12.63,while theabrownin was increased from 14.0% to 16.61%,but theaflavins,thearubigins were increased first and then decreased during the fermentation process of Acanthopanax sentieosus tea.In addition,cellulase,pectinase and protease hadbeen there as the endogenous enzyme before generating microorganisms,while polyphenol oxidase were exogenous enzymes.The main quality components and enzymatic activity changed obviously as the time was prolonged,the quality of Acanthopanax sentieosus tea were improved effectively.3.The volatile constituents and tastes in the tea were analyzed by electronic nose,electronic tongue and gas chromatography mass spectrometry(GC-MS),the results showed that the flavor of tea changed obviously during the different fermentation times.The radar chart analysis showd that the electronic nose was sensitive to the aroma components of the tea,and can quickly and non-destructively detect the aroma components of the tea.PCA and LDA can distinguish tea flavors well.The olefins were the main components of volatile aroma compounds in Acanthopanax sentieosus tea,the content of olefins were increased from 19.37 to 44.59.The bitterness and astringency of fermented tea were significantly decreased from 4.92 and 7.72 to 2.26 and 6.49,which effectively improve the flavor of Acanthopanax senticosus tea.