Study On Brewing Technology Of Wild Blueberry Icewine

Blueberry belongs to the azaleidaeVaccinium plants,also known as cranberry,blue berries.Blueberry is nutrient-rich fruit,containing a lot of anthocyanins,anthocyanins and other substances.These substances are helpful for human healthy for it have some excellent functions,including anti-aging,prevent cardiovascular,protect vision.Further more,blueberry also contains a large number of human essential amino acids,carbohydrates,trace elements.Thus,blueberry is one of five top health foods identified by the United Nations.However,the harvest time of blueberries is around August,it is costly to preserve as fresh fruit for a long time.Therefore,processing the blueberry to wine is one of potential choice.In this subject,we used wild blueberry as raw material,after pretreated by frozen and pressing,the sugar concentrations(without additional sugar adding)of the blueberry juice were achieve to the requirement of icewine fermentation.Different yeasts were tested in the fermentation experiments and a suitable yeast was finally screened out.The clarifying agents were also compared in the clarification experiment and the suitable clarifying agent for wild blueberry icewine was then identified.The main aroma components of wild blueberry icewine were analyzed by GC-MS method.The main results are as follows:1.Three kinds of yeast were used in the fermentation experiment.The yeast of the wild blueberry icewine was selected by physical and chemical testing and sensory evaluation and comprehensive analysis.Yeast A1 was considered as the suitable yeast for brewing wild blueberry icewine.The fermentation temperature,the amounts of A1 adding and the concentration of residual sugar were tested by single-factor test and orthogonal test,respectively.The results showed that the optimum fermentation conditions were as follows: fermentation temperature was 12 ?;amount yeast addition was 1.4%;residual sugar concentration was 165 g / L;The product of ice wine was tasted pure,typical high,rich aroma.2.The effect of bentonite,gelatin and chitosan on the clarification of wild blueberry raw wine was tested by comprehensive analysis.The results indicated that chitosan had the best clarifying effects compared to the other two agents.After clarified by 1600 ppm chitosan,the transmittance was 81.3%.3.The main aroma components of wild blueberry icewine and Inniskillin icewine were comparably analyzed by gas chromatography-mass spectrometry(GC-MS).The results showed that wild blueberry icewine contained 14 kinds of aroma substances;Inniskillin icewine contains 16 kinds of aroma substances.According to the comparative analysis,some of aroma substances of wild blueberry icewine were different to that of Inniskillin icewine.The unique aroma substances of wild blueberry icewine might be the main reason for it had the distinct taste.Further more,the two kinds of icewine shared some same aroma materials,but the proportion of them was different.In a word,the blueberry juice produced by the pretreatment of frozen and pressing achieved to the requirement of icewine fermentation.Combined yeast A1 and fermentation parameters,the blueberry icewine meet the icewine standard.