Study On The Optimization Of The Preparation Process Of Blueberry Wine

Blueberry,named for its blue fruit,is rich in nutrients.Blueberry fruit has a suitable ratio of sweet to acid,and its fragrance is refreshing.It can not only be eaten fresh,but also processed into by-products.In this paper,the brewing method of blueberry wine was studied.The blueberry in Zhuanghe City,Liaoning Province was selected as the experimental material.The enzymatic hydrolysis,fermentation,changes of antioxidant components in the main fermentation process and the effects of oak chips on the quality of blueberry wine during aging were systematically studied.The results are as follows:Firstly,by adjusting different enzymatic hydrolysis conditions in the process of blueberry juice enzymatic hydrolysis,the optimum enzymatic hydrolysis technology of blueberry juice was determined: pectinase 40 mg/L,enzymatic hydrolysis temperature 55 C and enzymatic hydrolysis time 60 min.Under these conditions,the juice yield of blueberry juice was the highest and the total antioxidant capacity was the best.Secondly,the yeast inoculation and initial sugar content during the fermentation of blueberry juice were investigated.The optimum fermentation conditions were obtained as follows: yeast inoculation 7%,initial sugar content 220 g/L,initial pH 4.0 and main fermentation time 8 days.Under these conditions,the alcohol content of the product was the highest and the residual sugar content was the lowest.Thirdly,the changes of total anthocyanin content,total phenol content,total antioxidantcapacity,·DPPH free radical scavenging capacity and superoxide anion free radical scavenging capacity during the fermentation of blueberry wine were investigated.The total anthocyanin content,total antioxidant capacity,·DPPH free radical scavenging capacity and superoxide anion free radical scavenging capacity were obtained.The change is that it rises first and then decreases to a stable level.The content of total phenol decreased.Therefore,in order to reduce the decline of antioxidant capacity in the process of fermentation,it is necessary to shorten the main fermentation time under the condition of ensuring complete main fermentation.According to the data,the optimum main fermentation time for blueberry wine was 8 days.Finally,the quality changes of blueberry wine during aging were explored by adding oak chips with different baking degrees: the total sugar content increased after adding oak chips,the total acid content increased most when adding light baked oak chips,the total phenol and tannin content increased,and the moderate baked oak chips increased.The blueberry wine with moderately baked oak chips tastes best.