Detection Of Non-anthocyanin Phenolic Substances In Cabernet Sauvignon Grape Of Different Growth Stages And Wines In Hexi Corridor

Non-anthocyanin phenol is a secondary metabolite in grapes.It changes complex during grape maturation.And the content is affected by factors such as variety and origin,and it play an important role.in bitter and astringent taste,color,storage life and biochemical stability.Therefore,studying the change of composition characteristics of non-anthocyanin phenol in grape fruit ripening is helpful to understand the characteristics of varieties and origin styles of wines from the perspective of non-anthocyanin phenols.In this experiment,single factor combined with response surface methodology were used to optimize the extraction conditions of polyphenols in wine.And UPLC-MS technology was applied to analyze different vinyards of Hexi Corridor(38°,Mogao,Guofeng and Zixuan).The changes of Non-anthocyanin composition and content of Cabernet Sauvignon were anlaysed during different growth stages and dry red wine.The main findings were as follows:(1)This experiment established a method for determining of 38 non-anthocyanin phenolic compounds,such as hydroxybenzoic acids,hydroxycinnamic acids,flavonols,flavanols,and terpenoids(resveratrol).The equmpiment contration was water(0.2% acetic acid)-acetonitrile as the mobile phase A,B,and UPLC-MS/MS with negative ESI mode.This method has a lower detection limit and higher repeatability and accuracy.(2)The optimum single factor conditions for the polyphenol extraction process were:50°C extraction temperature,40 min extraction time,1:3 ethyl acetate ratio,and 4 extraction times.Moreover,the result of response surface methodology showed that this method has obvious optimization effect,and the best exteration content was 0.542±0.012 mg/L(P>0.05).(3).The results of total acid,and total phenol,hundred-grain weight showed that the rapidly decreased and increased respectively during the veraison.There were 33non-anthocyanin phenolic compounds detected by the UPLC-MS/MS,and the total amount was significantly different between periods and vinyard.The flavonols was the main compounds of non-anthocyanin phenolics,such as 38° had 83.60% concentration at T2 stage.The content changes of flavonols were similar to the total amount of non-anthocyanin phenols.In general,the trend of the 38° and Mogao vinyards were same,and meanwhile,the similar results were also found between Zixuan and Guofeng counterparts.(4)Cabernet Sauvignon dry red wines,producted by Zixuan and Guofeng companies,were used as raw materials in this experiment.The results showed that the phenolic acids and flavanols were main non-anthocyanin phenols,including chlorogenic acid,catechin,dihydroquercetin,quercetin,ferulic acid,kaempferol and so on.The different vinyards andproduction years were the significant factors to affect the abovementioned compounds.Among the all tested red wine samples,the 2010 Zixuan(114.50 mg/L)and 2015 Guofeng(32 kinds)were hightest concentration and type of non-anthocyanin phenolics samples,respectively.