Analysis Of Wine Quality Of Six Grape Varieties And Construction Of Mono-phenol Fingerprints

In this study,we compared the quality characteristics of different grape varieties and the quality of their single-variety wines using wine grapes: Granoir(JNH),Dunkelfelder(ZDF),Meili(ML),Moldova(ME),Gongniang No.1(GN)and Beibinghong(BBH)as raw materials,and constructed a wine monomer phenol fingerprint profile in order to provide a theoretical basis for wine grape cultivation selection and wine variety identification.The main results of this study are as follows:(1)Analysis of six kinds of wine grapesIn six wine grapes,the ZDF grape had the largest ear quality.The ME grape had the largest grain quality along with the highest juice yield.The GN grape had the highest reducing sugar content and titratable acid content.The content of phenols in grape seed was higher than that in grape skin.The contents of tannins,flavanols,flavonoids,total phenols,and anthocyanins in ME grape's skin were higher than those of other varieties.The phenols content in seeds of JNH and ZDF grapes were higher than other varieties.The total content of organic acids in the six wine grapes was shown in descending order,i.e.,BBH > JNH >ME > GN > ZDF > ML.Seven kinds of acids including citric acid,tartaric acid,malic acid and succinic acid were detected in six varieties.The total content of aroma substances was decreased in the order of GN > BBH > ME > ZDF > JNH > ML.The principal component analysis shows that the three hybrid grapes were located at the positive end of the first principal component,and the Eurasian grapes were located at the negative end of the first principal component,above which indicate the grapes could be well distinguished in aroma.(2)Quality analysis of six single-variety winesThe physical and chemical indexes of the six single-variety wines meet the requirements of GB/T15038-2006.The content of reducing sugar,total sugar,alcohol,total extract and dry extract of the BBH wine was the highest among the six single-variety wines.The GN wine had the highest total acid,and the ME wine had the highest volatile acid.As for the phenolic substances,there were significant differences in different varieties of wine.The BBH wine had the highest total content of tannins,flavonoids,and total phenols.The GN wine had the highest content of flavanols and anthocyanins.The total content of tannins,flavanols,flavonoids,total phenols,and anthocyanins in ML wine were the lowest.The content of the six wines' monomer phenol compounds was shown in descending order,i.e.,GN > BBH > ME > ZDF > JNH > ML.Seven kinds of organic acids were all detected in six wines.Among them,succinic acid,tartaric acid,and malic acid were more than other acids in content,while oxalic acid,acetic acid,and citric acid were less.The organic acid content of the ML wine was the lowest among the six single-variety wines.The total content of aroma substances in the six single-variety wines was shown in descending order,i.e.,ML > BBH > GN > ZDF > JNH > ME,and the descending order for richness of types was ML > BBH > GN > JNH > ZDF > ME.The aroma content and the richness of ML wine were relatively prominent.Combined with the results of principal component analysis,ML wine was located at the positive end of the first and second principal components,JNH and ZDF wines were also located at the positive side of the second principal component.Moreover,ME was located in the third quadrant,and GN and BBH wines were located in the fourth quadrant.Different varieties of wines could be well distinguished in aroma.The sensory evaluation results of the six wines in descending order was BBH > JNH > ZDF >ME > ML > GN.The aroma of the JNH,ML and ME wines was mainly fruity and the spice flavor of the BBH wine was more obvious while the aroma of the ZDF and GN wines was more complicated.(3)Construction of monomeric phenols fingerprints for six single-variety winesAfter methodological verification,the UPLC fingerprint method with great precision,repeatability and stability were used to establish a fingerprint of monomeric phenols.According to the retention time,15 monomeric phenol compounds in the six wines were qualitatively identified.The peak time of the same compound in different wines was similar,but the overall peak shapes were different,thus,it can be used to distinguish the variety of wines.Based on methodological investigation,it is proved that the UPLC fingerprints of the six wines meet the national standards.The results of similarity evaluation and cluster analysis show that the monomer phenol fingerprints established in this experiment can be used for wine quality detection and variety identification.