The Best Harvest Time Of Grape Cabernet Sauvignon And Chardonnay In Heshuo County,Xinjiang Province

The experiment was conducted in Quhui Town,Heshuo County,Xinjiang Province in 2011.Two genotypes of winegrape varieties,Cabernet Sauvignon and Chardonnay were chosen as experimental materials,and agronomic characters,physicochemical composition,phenolic composition and antioxidant activity of these grapes at different harvest dates were detected,and their brewing characteristics and wine quality were evaluated.So as to determine optimum harvest time of Cabernet Sauvignon and Chardonnay and provide basis for related research in other wine region.The main results as follows:1.Mature process,the change of bunch grapes weight of Chardonnay is ’S’ type,their bunch grapes weight and juice yield were maximum on August 25 and 31 respectively.The change of bunch grapes weight of Cabernet Sauvignon is inverse ’S’ type,their bunch grapes weight and juice yield were maximum on September 12 and 3 respectively.Delaying harvest appropriately,the yield of Chardonnay and Cabernet Sauvignon grapes and wine were improved.2.Mature process,sugar content of grape berry were rising and their acid content were descending continually.Negative correlation was highly significant between sugar content and acid content.Sugar and acid content of Cabernet Sauvignon were higher than those of Chardonnay on the same harvest date,and acid-sugar ratio(M value)were 17.55～45.67 and 9.83～45.87,reached 20 on August 19 and August 7,respectively.It means that Cabernet Sauvignon and Chardonnay began to mature on August 7 and August 19,respectively.Physicochemical composition of wine was significantly correlated to harvest dates.Delaying harvest winegrapes could improve wine alcohol,reduce its acidity.3.Mature process,the content of phenolic composition were significant positive correlation to each other,but the difference were obvious.The tannins content was most in these phenolic.Cabernet sauvignon each phenolic compounds was obviously higher than chardonnay,but both change trend were similar,all followed the regulation of after the first decline rise.Each phenolic composition content of Cabernet sauvignon respectively in September 6～12 reached maximum,and Chardonnay was earlier,respectively in August 10～13 reached maximum.Excessive delaying harvest time would reduce phenolic content in chardonnay and wine,and appropriate delaying harvest time would be beneficial to accumulate phenolic compounds of Cabernet Sauvignon.4.Comprehensive analysis ripe coefficient,polyphenols content of grape,sensory evaluation of wine and other related indexes,the results showed that:the optimum harvest time of Chardonnay in Heshuo were from August 10 to 13,and it was not suitable for being delayed harvest;the optimum harvest time of Cabernet Sauvignon in Heshuo were from September 6 to 12,and it was allowed to delay harvest.