Effects Of Light On Phenols And Aromas In The Beibinghong V.amurensis Rupr From The Color Conservation To The Frozen Period

Beibinghong Vitis amurensis Rupr is a new bisexual flower species,which is made from female parent"Zuo Youhong"and the male parent Shanou F₂ generation grape strain"86-24-53"through interspecific hybridization.It has good cold-resistance and disease-resistance characteristics,and it is harvested through the color conservation till the frozen period,as the main raw material for brewing ice wines currently.Phenolic and aromatic substances are very important components in grapes and wines,which play an extremely vital role in the wine quality such as color and stability.Light also has an effect on the production of phenolic and aromatic substances in grapes.In this study,HPLC and GC-MS techniques were used to analyze thematerial changes of phenolic and aroma substances through the color conservation till the frozen period in the normal light and dark growth of the Beibinghong V.amurensis Rupr.The main research results obtained in this experiment are as follows:（1）The total phenolic content of Beibinghong V.amurensis Rupr grown under light and dark conditions showed an increasing trend first and then decreased in content.At the end of maturity,the total phenol content reached the highest.However,the total phenol content of Beibinghong V.amurensis Rupr under dark conditions was growing at a slower rate,and the total phenol content of Beibinghong V.amurensis Rupr was also 0.12 mg/g lower than those normally growing on picking day.（2）The dark treatment has changed the growing trend of monomeric phenols.The experimental results showed that 14 kinds of monomeric phenolic substances were detected in thenormal growth conditions of the Beibinghong V.amurensis Rupr.Among them,the contents of gallic acid,syringic acid,salicylic acid,caffeic acid,coumaric acid,ferulic acid,quercetin,kaempferol,resveratrol,and myricetin all showed a tendency of increasing first and then decreased.The content of protocatechuic acid,vanillic acid and epicatechin decreased first and then increased.However,the content of chlorogenic acid has been decreasing.At the day of picking on November 30,the chlorogenic acid content was only 0.03 mg/100 g,which was0.341 mg/100 g lower than the amount initially determined.The contents of gallic acid,vanillic acid and chlorogenic acid in Beibinghong V.amurensis Rupr have declined under the dark conditions,and the content of syringic acid,salicylic acid,and coumaric ferulic acid increased first and then decreased.The content of acid,epicatechin,and quercetin decreased first and then increased.However,the resveratrol content did not change significantly and it has been fluctuating within the range of 0.03-0.06 mg/100g.While caffeic acid and kaempferol only appeared during the first determination process,they were not detected afterwards.The results showed that the dark treatment had a certain effect on the content variation of monomeric phenols in Beibinghong V.amurensis Rupr from the color conservation till the frozen period.（3）The dark treatment has changed aroma substances in the Beibinghong V.amurensis Rupr.The experimental results showed that a total of 34 kinds of volatile aroma components were detected in the light growth of the Beibinghong V.amurensis Rupr,accounting for 96.34%of the total peak area,on August 27^th.A total of 36 kinds of volatile aroma components were detected in the dark growth of the Beibinghong V.amurensis Rupr,accounting for 94.19%of the total peak area.On October 10^th,a total of 38 kinds of volatile aroma components were detected in the light growth of the Beibinghong V.amurensis Rupr,accounting for 99.30%of the total peak area.A total of 39 kinds of volatile aroma components were detected in the dark growth of the Beibinghong V.amurensis Rupr,accounting for 99.73%of the total peak area.On December 2^nd,a total of 31 kinds of volatile aroma components were detected in the normal growth of the Beibinghong V.amurensis Rupr,accounting for 96.73%of the total peak area.A total of 39 kinds of volatile aroma components were detected in the dark growth of the Beibinghong V.amurensis Rupr,accounting for 97.71%of the total peak area.Under the light conditions,the contents of alcohols,acids and alkanes gradually decreased,and the content of esters increased through maturation till the frozen period.However,under the dark conditions,the content of alcohols,esters,and alkanes gradually increased,and the content of acids decreased.It showed that under light and dark conditions the content of acid gradually decreased and the content of esters increased.Therefore,it was found that dark conditions did not affect the synthesis of acids and esters.Instead,it promoted the synthesis of alcohols and inhibits the synthesis of alkanes.