Research On Optimization Of Brewing And Antioxidant Capacity Of Blueberry Wine

Blueberry is called "Third-generation Fruit" because of its high content of anthocyanins, citric acid, chlorogenic acid, superoxide dismutase(SOD), pterostilbene, polyphenols, and outstanding role in antioxidant and anticancer. But the shelf life of blueberry is less than two weeks, which makes it hard to sale. Deep-processing of blueberry can solve the problem of putridity, improve its additive value, and promoting the development of blueberry industry in some way. The acidity and suger content of blueberry also make it to be a good fruit in wine making.In order to obtain quality yeast for blueberry wine, a total of 122 yeast strains were isolated from different blueberry fruits, leaves, and orchard soil. Through microscopy test and duchenne tube fermentation, a yeast named BBF-17 showed excellent performance for alcoholic yield test along with tolerance test, compared with the others and K yeast. When identified by 18S rDNA sequences and phylogenetic analysis, the results of molecular biology identification showes that it was nearest to Saccharomyces cerevisiae(EU649672.1), has a similarity of 99%. The strain was identified as Saccharomyces cerevisiae.Useing BBF-17 as fermentative strain, we can inspect the infulence resulting from fermntation time, in oculation volume, fermentation temperature and sulfur dioxide amount on the quality of blueberry wine, through single factor analysis and response surface experiments. The best fermentation conditions are as follows:the inoculation volume is 5%, the fermentation temperature is 28℃, the amount of SO2 is 250 mg/L, the main fermentation time are 7 days.The content of anthocyanins and polyphenols are 709.62 mg/L and 6871.48 mg/L, the total antioxidant capacity can even reach 5643.53 mgVc/L.Using Caenorhabditis elegans as the model organism to study the effects of blueberry wine on physic, biochemistry indices, and antioxidant enzyme activity of Caenorhabditis elegans. The results show:Blueberry wine can extend Caenorhabditis elegans’ lifespan of 1.17 times, improve their exercise capacity about 1.31 times, spawning numbers 1.2 times; reduce the content of intracellular free radical about 31 percents, the number of apoptosis; and improve the activity of antioxidant enzyme of Caenorhabditis elegans 1.21-2.94 times. This experiment proves that blueberry wine have both good antioxidant capacity and physiological effect.