Research On Maturity Changes Of Red Wine Grapes In Different Regions Of Xinjiang

Xinjiang have a large content of light and heat conditions,with little precipitation and superior geographical advantages.In recent years,Xinjiang wine industry has been growing.in addition to brewing process,wine quality also with the quality of grape raw materials,which is great significance to improve the quality of grape wine.there will be some difference of the quality,polyphenol content and aroma of grape fruit due to different varieties and producing areas.In this experiment,Cabernet Sauvignon and Merlot grape from different producing areas in Xinjiang are taken as the experimental objects,which explore the dynamic changes in quality of grapes in various regions during ripening,polyphenol-related enzyme activities,and the aroma substances at maturity period of grape.The main results are as follows:1.The physical and chemical indicators of grapes in various regions were measured during ripening.The soluble solid content,reducing sugar content,and sugar-acid ratio of Hami,Changji,Heshuo,and Yili Cabernet Sauvignon and Merlot grapes during maturity were increased.The titratable acid content showed a declining trend,the 100-grain weight as showed a gradual upward trend and stabilized at a later stage.2.The change trend of polyphenols content in peel of Cabernet Sauvignon and Merlot grape at different producing areas is different.Compared with Cabernet Sauvignon from four regions,the polyphenols in the peel of Cabernet Sauvignon from Changji are higher,and the sugar content and maturity of Cabernet Sauvignon from Heshuo are higher;compared with Merlot from four regions,the polyphenols in the peel of Yili Merlot are more prominent and the sugar-acid ratio of Changji Merlot is better.Combining Principal Component Analysis and actual production forecast that the best harvest time of Hami Cabernet Sauvignon grape should be around August 31st,and Merlot grape should be around September 7th;the best harvest time of Changji Cabernet Sauvignon and Merlot grape should be around September 19th;the best harvest time of Heshuo Cabernet Sauvignon should be around September 13th,and Merlot grape should be around August 27th;the best harvest time of Yili Cabernet Sauvignon and Merlot grape should be around October 5th.3.The content of polyphenols and the activity of related enzymes in the peel of Merlot grape in two years were determined.It indicates that during the ripening process of Merlot grape fruit,the content of phenolic substances in the peel are regulated by various enzymes.The correlation analysis showed that except for anthocyanin and flavanol,there was a significant positive correlation between polyphenols in the peel of Merlot grape.Between polyphenols and related enzyme activities,anthocyanins were significantly positively correlated with PAL;POD and C4H were significantly positively correlated with flavonoids.4.Through GC-MS,a total of 60 kinds of aroma substances were detected in Cabernet Sauvignon and Merlot grapes in four regions.There were some differences in the types and contents of aroma substances in each region.The aroma of grape fruits had their own characteristics,and the outstanding aroma substances were also different.Cluster analysis shows that Cabernet Sauvignon grapes can be divided into two categories,one is Changji and Yili Cabernet Sauvignon grapes,the other is Heshuo and Hami Cabernet Sauvignon grapes;Merlot grapes can be divided into three categories,Hami Merlot grapes as a category Heshuo Merlot grapes as a category,and Changji and Yili Merlot grapes are divided into one category.