Research On Fermentation Technology Of Blueberry Wine

The fruit of blueberry plants belonging to Vaccinium Genus of Rhododendron family is nutritious which is rich in VA、VB、 VC、VE、arbutin, anthocyanin, SOD, protein, dietary fiber and mineral elements potassium, iron, zinc, calcium, in addition to containing sugar, enzyme, Vc. Anthocyanin content of blueberry lists first among more than40kinds of fruit which has endowed blueberry with strong antioxidant ability and good function of brain-aging-prevention, heart-enhanced, anticancer.By using blueberry as raw material to develop blueberry wine, the study mainly researched on the fermentation technology, the changes of anthocyanin and organic acid before and after fermentation, and flavor material.Optimal fermentation parameters of blueberry wine was determined by single factor experiment of which pectinase, potassium metabisulfite, inoculating amount, initial sugar degree, initial pH were0.25%,0.01g·L-1,1.0g·L-1,220Bx, pH3.3respectively, and the process was carried on at fermentation temperature24℃for10days.On this basis, the multiple regression model was established between inoculating amount, initial sugar degree, fermentation temperature, initial pH and blueberry wine alcohol degree through response surface analysis, and the equation of alcohol degree could be calculated by the following equation:alcohol degree=10.90+0.29A-0.33B+0.53C+0.64D-0.15AB-0.17AC+0.100AD-0.13BC-0.22BD+0.30CD-1.66A2-1.07B2-0.92C2-1.56D2;Results showed that blueberry wine alcohol degree of10.9%was obtained on the optimization fermentation conditions of which inoculating amount, initial sugar degree, fermentation temperature and original pH value were optimized as1.00g-L’1,21.9°Bx,25.0℃and pH3.41respectively.Content of total anthocyanins of blueberry juice was146.79μg-mL-1by using high performance liquid chromatography; After fermentation, the content of total anthocyanins of blueberry fruit wine was163.31μg·mL-1, which showed that anthocyanins of blueberry was effectively extracted during fermentation process; the content of oxalic acid, a-ketoglutaric acid, citric acid and succinic acid was decreased by testing of organic acid during blueberry wine fermentation process; and the content of malic acid and lactic acid with being characteristic of softer acid was increased, and the content of malic acid and lactic acid has been increased by6times,14.5times especially after fermentation, which is of great importance to blueberry wine taste. Forty seven aroma components from volatile materials of blueberry wine were identified through ATD-GC-MS technology, of which the kinds of alcohols, esters, acids, ketones, aldehydes; heterocyclic compounds, acid anhydride and alkane were13,10,4,7,5,5,1,1respectively.The main flavor materials were as follows:Isopentyl alcohol, Acetone alcohol,1-Hexanol,2,3-Butanediol, Phenylethyl Alcohol, Maltol, Methyl acetate, Ethyl Acetate, Ethyl2-methylbutyrate, Isoamyl acetate, Methyl hexanoate, Ethyl hexanoate, Ethyl2-hydroxypropanoate, Ethyl caprylate, Butyrolactone, Methyl3-furoate, a-Angelica lactone, n-Hexadecanoic acid, Palmitoleic acid,2,3-Pentanedione, Dihydro-2-methyl-3-furanone, Acetophenone,2(5H)-Furanone,3,5-Dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one, Nonanal, Furfural and etc.