Screening Of Fine Cider Yeast Strain And Study On Brewing Technologies Of Cider

China's one apple producing country,due to insufficient processing of apples,has caused a serious waste of apple resources in China.Due to its low alcohol content,good taste,and the higher nutritional and health benefits,making it the best choice for apple further processing.In order to improve the winemaking technology,stabilize the fruit wine processing technology,and provide a certain theoretical basis for brewing the higher-quality apple wine research and development and actual production,this paper mainly designs from two aspects:First,screening out the excellent yeast strains suitable for cider brewing,randomly sampling from the one local orchard in Handan of its apple skin and soil,and separating and purifying the flora,and preliminary obtained 42 strains of gas producing strains,5strains?Y1,Y2,Y3,Y4,Y5?strains with good gas production,and five commonly used yeasts?1#,2#,3#,4#,5#?have undergone different single factor tests:fermentation capacity test,alcohol tolerance test,SO₂ tolerance test,nutritional starvation tolerance test,found that 5 strains of yeast?3#,4#,5#,Y1,Y3?fermentation broth body light,wine and fruit fragrance coordination,but natural screening Strain Y1 and Y3 can tolerate a certain concentration of SO₂,but it has strong inhibition and is generally resistant to hunger.Second,using Fuji apple as raw material,firstly adopting composite color-protecting agent for orthogonal optimization to inhibit browning of apple juice,selecting single factor experiment of sucrose addition amount,initial pH value and fermentation time design,and on this basis,As a response index,the fruit wine comprehensive score was analyzed by the Box-Behnken program and the regression equation model.The main results are as follows:The best color protection process:2%NaCl,0.2 g/L Sodium Erythorbate,0.6%citric acid,and 15 min treatment time,which inhibited the browning effect of juice.The response surface analysis method was used to establish a multivariate regression equation for the effects of sucrose addition,pH and fermentation time on the sensory quality of cider.The best brewing process was as follows:sucrose addition15.9%,pH 3.5 and fermentation time was 11 days.Under this optimal conditions,the sensory score was 84.40,the test score was 84.33,the alcohol content was 13.9%,the residual sugar?soluble sugar?was 1.14mg/mL,and the primary and secondary factors affecting the fermentation were determined.Sequence:sucrose addition amount?A?>pH value?B?>fermentation time?C?.Under the optimal process,the mixed fermentation test of yeast double strains was carried out.The appearance of cider was light yellow,the liquid was clear and translucent,and there was a slight sediment at the bottom.The apple aroma and the wine were harmonious,no odor;the sweet and sour was moderate.The sensory score was 85.7 and the alcohol level was 10.6%.