Study On Brewing Technology And Quality Of 'Guankou Grape' Dry White Wine

'Guankou grape'originated in Jianshi County,Enshi,Hubei Province.It has large and compact ears and rich aroma.It is named for its origin in Guankou Township.'Guankou grape'is a fresh food species with strong seasonality.Due to the increase of planting area and yield,the'Guankou grape'has a serious problem of unsalability.Fresh food alone can not meet the needs of production.Fruit wine brewing is the first choice for sustainable development.However,there are some technical problems in the production of'Guankou grape'dry white wine,such as low juice yield(only about 30%),easy oxidation of broken grape juice,no outstanding aroma of varieties,etc.In the early stage,we systematically studied the different processing technology and the comparison of polyphenol oxidase characteristics of'Guankou grape'dry white wine,solved a series of processing problems such as easy oxidation and difficult to get juice during the brewing process,and produced dry white wine with the characteristics of this variety.However,there were still some problems in the production process,such as bitterness.The phenomenon of higher strength.Therefore,this paper studies the brewing technology and sensory quality of'Guankou grape'dry white wine from the fruit itself,in order to develop dry white wine suitable for the characteristics of this variety.The main results are as follows:(1)The phenolic substances in'Guankou grape'mainly distribute in grape seeds;the aroma substances mainly exist in the pericarp;the terpene substances in the pericarp are the highest,accounting for 33%of the total aroma.(2)Different juice extraction processes have different effects on physical and chemical indexes and quality of'Guankou Grape'dry white wine;low temperature impregnation before fermentation can improve the quality of wine better,and self-flowing juice after low temperature impregnation has the best overall evaluation of appearance and taste.(3)With the increase of low temperature soaking temperature,the content of phenolic substances in wine first increased and then decreased;the content of aroma substances gradually increased;the quality of wine produced at 5?1(?)C was higher.With the increase of pectinase content,the content of phenolic substances increased,and the overall quality of'Guankou grape'dry white wine could be improved when the content of pectinase was 40mg/L.With the prolongation of soaking time,the content of phenolic substances increased first and then decreased;the total amount of aroma substances decreased first,then increased and then decreased;the aroma quality,taste and overall score of wine samples soaked at low temperature for 24 hours were the highest.(4)The optimal fermentation parameters were obtained by using the sensory score as the response value through the quadratic general rotational combination design of three factors(fermentation temperature,initial p H value and initial sugar content),and the fermentation temperature was 16.11 C,the initial p H was 3.72,and the initial sugar content was 204 g/L.(5)Relevance study found that:Volatile acid,residual sugar,SO₂,flavonoids,flavanols,flavonols,cinnamic acid monomer phenols and monomer phenols were not significantly correlated with the quantitative intensity of taste(P>0.05);total phenols,tartaric acid lipids and benzoic acid monomer phenols had a greater impact on the bitterness of wine;sweetness was positively correlated with polysaccharides;hot and hot taste was positively correlated with alcohol content.Honey peach,pineapple,musk grape and lipids,especially ethyl acetate,ethyl butyrate,isoamyl acetate,have obvious correlation.There was no significant correlation between liquorice,apple,bitter almond and black coffee aroma and wine-like aroma substances.