Brewing Process And Quality Evaluation Of Compound Liqueurs And Distilled Spirits From Major Fruits Of Shaanxi Province

Suffering from the problems of overproduction and insufficient deep processing of fresh fruits in recent years,four kinds of advantage fruits（apple,kiwifruit,pear and table grape）in Shaanxi Province were used to brew single fruit fermented wine and distilled spirits respectively,which consisted of low-temperature maceration and fermentation process combining with flavor blending technique and quality evaluation.It aims at developing the processing technology of high-quality compound fruit liqueurs and distilled spirits to enrich fruit wine types,which may not only effectively solve the problem of surplus of fresh fruits in our province,but also increase the added value of fruits and improve the economic income of fruit farmers,promoting the rapid and high quality development of local fruit industry.The main results obtained are as follows:（1）Optimization of fermentation conditions for high-quality kiwifruit wine based on low-temperature maceration and fermentation processA low-temperature maceration and fermentation process was used to make fruit wine from Huayou kiwifruit,and the optimal maceration fermentation time and fermentation conditions suitable for making high-quality kiwifruit wine were investigated through physiochemical index measurement and sensory evaluation.The results showed that 8 d of maceration and fermentation at 15℃was the best condition for separating the peel;the best fermentation conditions for quality kiwifruit wine were selected by orthogonal tests:fermentation temperature of 14℃,initial sugar content of 234 g/L,pectinase addition of 60mg/L,and yeast addition of 160 mg/L.The kiwifruit wine made under this process had a juice yield of 76.02%,a methanol content of 282.79 mg/L and a sensory score of 84.38 points;it was lemon-yellow in color,clear and transparent,with a predominantly fruity aroma and aromas of honey and cream,and with a soft and refreshing body.（2）Screening of high-quality compound liqueurs and distilled spirits based on flavor blending techniquesFour single liqueurs and eight compound liqueurs with a range of 15%to 18%vol alcohol content were obtained through sensory evaluation and flavor blending,using fermented wines and distilled spirits of each fruit as the base wines.After 3 months of bottle storage,the compound liqueurs showed higher flavor complexity and stability,and higher antioxidant activity compared to the single liqueurs.The kiwi-based compound liqueurs （KAP、KA and KP）were particularly well characterized by their lemon-yellow color,fruity aroma,smooth mouthfeel,moderate sweetness and acidity,and full body,with the average methanol content of 380 mg/L.Four single distilled spirits and four compound distilled spirits with a range of 43.43%to 46.25%vol alcohol were also obtained using single distilled spirits of four fruits as the base spirits.Compared with single fruit distilled spirits,the compound distilled spirits（especially G₁K₁ and G₁K₁P₁）had more complex and intense aromas.（3）An aging technique developed for obtaining low methanol and high-quality apple distilled spiritsThe high methanol content in apple distilled spirits was reduced by removing"head and tail"of distillates,and the effects of different roasting levels of oak blocks on apple distilled spirits were investigated.The results showed that the methanol content of the secondary distillate was lower when the head and tail was 8%and 20%of the primary distillate;the distilled spirits aged for 25 d in heavily toasted oak blocks had the best performance,containing higher total esters,total phenols and tannins and lower methanol content,with light amber color,complex and intense aroma,in particular oak and baked aromas in addition to the characteristic aromas of the variety,and soft and balanced body on the palate.