The Study On Way Of Evaluation Dry Red Wine Astringency Intensity And Its Effection Factors

The astringency of dry red wine is caused by the compound of saliva protein and polyphenol combination,and it brings drying,coarse,and puckering in oral cavity and belongs to tactile sense.According to reaction mechanism,there exist many analysis methods in vitro.Astringency would be enhanced or weaken with the change of ethanol,total acid concentration,pH value and temperature of red wine.The different polyphenol and chemical construction will cause both velvety astringency and puckering astringency,and the former mainly derived from polyphenol esters,while the later caused by mono phenol.The paper manages to realize objectively evaluation dry red wine astringency and analysis synthetic wine to replace wine through establishment the correlativity of sensory evaluation and chemical measurement of dry red wine,and also correlativity of dry red wine and synthetic wine.In order to exploring the effect of ethanol,total acid,pH value and drinking temperature on astringency,the research analysis the change of astringency intensity in synthesis wine.At last,the paper verification astringency evaluation by analysis the content of mono phenol which caused the puckering astringency in dry red wine.The main results demonstrated as follows:1.By means of SDS-PAGE and sensory evaluation to analysis dry red wine and synthetic wine with the same chemical index of wine,results show that astringency intensity Pearson coefficient of dry red wine and synthetic wine is 0.497 through sensory evaluation.While the astringency intensity Pearson coefficient of dry red wine and synthetic wine is 0.900 by SDS-PAGE,so the synthetic wine can replace dry red wine for further studying.2.Single factor experiment of synthetic wine to determine 0-7-11-13-15%as the ethanol gradient,2.0-2.5-3.0-3.7-4.5 as pH value gradient,0-1.0-2.0-4.0-6.0 g/L as total acid gradient,10-18-25-37-45? as temperature gradient.Result shows that all of the index changing can affect astringency intensity.In synthetic wine,we get the quadratic regression model of four factors effecting astringency intensity by quadratic-rothogonal-rotation-combination:Y=85.8833-1.44667X1-4.41917X2+5.65083X3+2.30667X4-1.22271X12-5.24271X22-6.76146X32-0.48896X42+1.34750X1X2+1.61625X1X3-1.52000X1X4+2.14750X2X3+1.17375X2X4+0.46750X3X4After significance testing of regression coefficient and get rid of non-significance part,we get the optimization model:Y= 85.88333-4.41917X2-5.65083X3+2.30667X4-5.24271X22-6.76146X32After analysis factors main effects and interaction effects,results show that pH value is the most effective factors,and then total acid and temperature,the least factor is ethoal.pH value and total acid interaction effects show significant,ethanol and temperature has less effect.3.By means of high performance liquid chromatography(HPLC)to determination the content of(+)-catechin,vanillic acid,caffeic acid,syringic acid,(-)-epicatechin,gallic acid,p-coumaric acid and ferulic acid,these are mono phenol which bring puckering astringency in dry red wine.Result shows that the most astringency wine contain higher content of vanillic acid,syringic acid and gallic acid.These mono phenol play the most role in enhance red wine astringency.While the wine storage in oak barrel show less astringency and mono phenol contents.