Study On The Brewing Process And Flavor Characteristics Of Persimmon Wine

Through the research and optimization of the astringent process of persimmon fruit,the preparation process of persimmon juice,the fermentation process of persimmon wine and the clarification process of persimmon wine,and the changes of tannin and flavor substances during the persimmon wine brewing process,the following results in conclusion:(1)Preparation process of persimmon juiceThe effect of combined use of pectinase and cellulase on the yield of persimmon juice was explored.Through the single factor test and orthogonal test,the best enzymatic hydrolysis process is obtained: the pectinase addition amount is 4g / L,the cellulase addition amount is 3g/ L,the enzymolysis time is 5h,the enzymolysis temperature is 40 ? The juice yield is 66.04%.(2)Optimization of fermentation process of persimmon wineUsing persimmon juice as raw material and SY Angel yeast as fermentation strain,the effects of fermentation temperature,initial acidity,initial sugar content and yeast inoculation amount on the quality of persimmon wine were investigated by single factor test and orthogonal test.The best fermentation process was obtained: fermentation temperature 20 ?,initial acidity7.5g / L,initial sugar content 200 g / L,yeast inoculation amount 0.2g / L.Under this excellent combination,the sensory score of persimmon wine is 92 points.(3)Analysis of aroma components of persimmon wineUsing the three techniques of electronic nose,gas phase mass spectrometry and sensory evaluation to analyze the aroma components of persimmon wine with different brewing processes,the following conclusions were obtained:A.Comparing the aroma components of the three fermentation methods of fruit pulp,clear juice and skin residue fermentation,the aroma components of the persimmon wine fermented by clear juice and skin residue are similar;the content of esters,alcohols and aldehydes in the aroma components of persimmon wine fermented by clear juice Most,the highest sensory score.B.Comparing the aroma components of three yeasts,F15 yeast,RW Angel yeast,and SY Angel yeast,the aroma components of persimmon wine fermented by RW Angel yeast and SY Angel yeast are similar;the aroma components of persimmon wine fermented by SY Angel yeast Medium esters,alcohols,aldehydes and other content,the highest sensory score.C.Analyze the aroma components of persimmon wine by gas-mass spectrometry combined with the best process,and obtain 68 kinds of volatile substances in aroma components of persimmon wine,15 kinds of alcohols,27 kinds of lipids and 8 kinds of alkanes There are 7kinds of acids.The main aroma components of persimmon wine include: 3-hydroxy-2-butanone(milk aroma),isoamyl alcohol(with apple brandy aroma and spicy flavor),isoamyl acetate(pleasant banana flavor),phenylethanol(rose pattern)Aroma),diethyl succinate(pleasant smell),etc.(4)Detection conditions of tannin components and changes of tannin components during fermentation of persimmon wineA.Using a high-performance liquid chromatograph,the chromatographic column was selected from Thermo Fisher's(Hypurity HPLC C18 4.6 * 250mm),the mobile phase was 0.01%formic acid(V): acetonitrile(V)= 90: 10,the column temperature was 30 ?,the flow rate Under the chromatographic conditions of 0.8m L / min,injection volume of 20?L,and detection wavelength of 220 nm,the separation effect of tannin components was good.B.By analyzing the components of persimmon tannin by high-performance liquid chromatography,the content of gallic acid in the fermentation process of persimmon increased continuously,reaching 45.02 ?g / m L on the 8th day of fermentation,but the content decreased again until 44.2 ?g / m L.The content of catechins did not change much,and the content of the second day of fermentation was high,reaching 4.01 ?g / m L.As the fermentation progressed,the content gradually decreased.The content of epicatechin reached its maximum on the fourth day of fermentation,which was 0.86 ?g / m L,and then decreased.Through the experiment,it is concluded that the trend of the total change of the persimmon tannin components during the fermentation process is to increase first and then gradually decrease.(5)Study on the clarification process and stability of persimmon wineA.Comparing the effects of natural clarification,membrane filtration clarification,centrifugal clarification and clarifying agent clarification,it was found that the effect of clarification with clarifying agent is better.After adding chitosan 0.04 g / L,the light transmittance of persimmon wine reached 96.8%.According to the electronic nose,chitosan clarified and naturally clarified persimmon wine have little difference in odor and many volatile components,so choose chitosan clarified persimmon wine.B.Persimmon wine stability test: by testing protein stability,hydrogen tartaric acid stability,iron stability,copper stability,and oxidation stability,the fruit wine did not precipitate,indicating that the chitosan clarified persimmon wine,wine Body stability is better.