Study On Selection Of Suitable Varieties Of Ice Cider

In order to select suitable varieties for brewing ice cider,12 late-ripening apple varieties were used as experimental subjects to delay harvesting and brewing ice cider,and analyzed the changes of physical and chemical indexes during the delayed harvest and freezing of apples and their effects on the quality of the brewed ice cider,the correlation ship between the physicochemical indexes of raw materials and the quality indexes of ice cider was established.The results were as follows:（1）In December,the temperature in Luochuan kept below-8°C for several times,which has the climatic conditions for the production of raw materials for ice cider.（2）Delayed harvest could change the physical and chemical properties of apples,and the change trends of physical and chemical indexes was similar in all varieties during the delayed harvesting.For example,sugar contents,p H value,total phenol contents increased,however,titratable acid contents and juice yield decreased.Significant differences in physicochemical indexes among different apple varieties after late harvest were observed.（3）In the process of wine brewing,the sugar content showed a downward trend,the alcohol content exhibited an upward trend,the titratable acid content increased but the p H value decreased in the fluctuation,and the total phenol content did not change obviously in the fermentation broth of all apple varieties.（4）The physicochemical indexes of ice cider brewed by apple varieties were significantly different.In all tested samples,the sugar content ranged from 2%to5.76%,the titratable acid content ranged from 2.05 to 5.68g/L,the p H value ranged from 3.25 to 4.01,the total phenol content ranged from 916.40 to 1466.50 mg/L,and the alcohol content ranged from 6%to 12%vol.As a result,when‘Luao’,‘Fuji Kiku’and‘Aixiang’were used as raw materials,the ice cider is golden and clear,fruity aroma,mellow and refreshing,unique flavor,and has the typical characteristics of ice cider,thus,these apple varieties are the preferred raw material for brewing ice cider.In addition,‘Golden Delicious’,‘Jonagold’,and‘New York No.1’also showed better brewing properties.（5）The correlation analysis was performed,and the results showed that the sugar content of the raw materials had a slight effect on the total phenol,color and taste of ice cider,but a significant influence on the alcohol content,style and comprehensive sensory score.Meanwhile,The acidity in apple raw materials mainly affected the acidity and p H of ice cider.Moreover,the p H value in the raw materials was significantly positively correlated with the p H value and color of the ice cider,and negatively correlated with the aroma and style,and the correlation was relatively high.Additionally,the total phenol content in the raw materials was significantly correlated with the total phenol content in the cider,and it also has an effect on the acidity of the ice cider.（6）Based on the multivariant linear stepwise regression analysis,a prediction model for ice cider indicators was established and verified.The model equations are as follows:acidity:Y₂=2.42+0.72X₂（R²=0.652）,p H value:Y₃=3.925-0.183X₂（R²=0.624）,total phenol:Y₄=180.572+0.867X₄（R²=0.337）,alcohol content:Y₅=4.661+0.667X₁-1.555X₃（R²=0.901）,aroma:Y₇=34.697-2.323X₃（R²=0.460）,style:Y₉=3.741+0.246X₁（R²=0.480）.The verification results found that the prediction model has a better prediction effect on the acidity,p H value,alcohol content,aroma,and style of ice cider,but has a poor prediction effect on the total phenol content.