Research Of Grape Polyphenols Maturity Parameters Based On Gansu Jiayuguan Region

JiaYuGuan city in Gansu province is one of the most important grape and wine region ofHexi corridor in china. Its unique climate attracts conditions both at home and abroad. Thewine industry started relatively late. Wine grape harvest time is determined mainly by sugaracid ratio. The index is relatively single, neglecting to unique elements especially phenolics ingrapes mature. This paper is intended to filter parameters of the maturity of the grapepolyphenols, in order to establish a new wine grape maturity index system. This study choseCabernet Sauvignon, Merlot and Camay, three grape varieties as experiment material, in2013,sampling grape peel and seed，determining phenolics (total polyphenols, flavonoids, flavanols,anthocyanins, tannins) content and evaluation four times. Finally analyze basic physical andchemical composition of grapes using principal component analysis method. Results:(1) The skin total polyphenols, flavonoids, flavanol and anthocyanins content rise afterthe fall of first, tannins increased in Cabernet sauvignon. The skin total phenol, anthocyaninscontent in the fall after rise first, flavonoids, flavanols, tannin content in mature periodgradually rise in Merlot and Gamay.(2) The total phenol, flavanol content in cabernet sauvignon seeds fall after rise first,flavonoids content increased, tannin content begins to decline gradually rise; Content of totalphenol, flavanol in Merlot seeds fall after rise first, flavonoids, tannins content showed a trendof increase and decrease after the first drop; Gamay seed total phenol, flavanol content riseafter the fall of first, flavonoids content after falling first increase trend, tannin contentshowed a trend of increase and decrease after the first drop.(3) Considering three varieties polyphenols maturity indicators, it can preliminarily bedetermined to characterization of grape polyphenols maturity indicators for the skin totalphenol, anthocyanins, flavonoids, flavonols.(4)) The grape maturity parameters F=M+X1skin total phenols+X2anthocyanins+X3flavonids+X4lavonols. When the Cabernet sauvignon F value of CS, ML, GM hasrelatively reached around55,77,73, it is considered the best grapes mature period.X1,X2,X3,X4are correlation coefficient with sugar acid ratio for each index.