Study On Fermentation Technology Of Blueberry Wine And Analysis Of Antioxidant Capacity In Blueberry Wine

Blueberry is rich in nutritional components, it’s one of five health fruits recommended by Food and Agriculture Organization(FAO), it can prevent aging of cranial nerve, potentiate cardiac action.against cancer, soften blood vessel、 enhance immunity. The health functions of Blueberry have connection with anthocynins and phenols, as the active components in blueberry, which can remove free radical and have great antioxidation capacity. The method of processing of Blueberry wine not only can make use of its unique nutrients and bioactive components, and also can improve its additional value greatly. What’s more, the Blueberry wine can meet the diversified development of beverage market and meet the needs of consumers. But Blueberry wine has a high level of organic acid, so it is meaningful to find a yeast that can efficiently degrade the organic acid and has a good fermentation performances. The pretreatment of blueberry and brewing technique, key parameters of fermentation are most important to brew a unique flavour and a high nutritional value blueberry wine which have health care functions.This article use Blueberry as main material,through mutation breeding of an L-malic acid-degradation yeast, pretreatment of Blueberry and optimizing key parameters of fermentation to brew a health Blueberry wine with low alcohol content, sour and sweet, delicious flavour and high antioxidation value. At the same time,the study provides the theory and research basis to the industrial production of Blueberry wine.The research content and results are described as following:1.An L-malic acid-degradation Saccharomyces cerevisiva FM-cs-08was treated for mutation by UV or60Co y-ray irradiation.The mutant strain FM-cs-08-2U, obtained by using60Co y-ray irradiation, whose deacidification rate of L-malic acid was29.48%, increased25.44%than FM-cs-08. The minimum pH was2.5, the maximum concentration of SO2was800mg/L, the maximum concentration of sugar was35%, the maximum of alcohol content was17.5%(V/V). The fermentation performance of the mutant strain was explored in blueberry wine. The degradation rate of sugar of FM-cs-08-2U was active, the residual sugar content of blueberry wine fermentated by FM-cs-08-2U was3.70g/L, pH was3.18, the organic acid concertraty was8.64g/L, the alcohol content was12%(V/V), it proved to be suitable for brew aging blueberry wine.2.The polyphenoloxidase in blueberry was inactive in2min by steaming heating, meanwhile the antioxidant was kept. Through single factor tests and orthogonal test, the optimum hydrolysis conditions were determined as follows:both the pectinase dosage and mulriple enzyme dosage0.3%, reaction temperature45℃, hydrolysis time3.5hours. After the enzymatic hydrolysis, the juice extraction percentage was72.51%, which is increased by77.18%compared with the extraction percentage in blueberry fruit juice without enzyme treatment;and total antioxidant capacity (T-AOC) of the juice was224.07units, increasing by96.45%compared with the blueberry fruit juice without enzyme treatment". In blueberry fruit juice,anthocyanin concentration is753.92mg/L, which is increased by2.40times compared with the the concentration of anthocyanin in blueberry fruit juice without enzyme treatment. The total phenol concentration reaches to2650.15mg/L, which is increased by75.66%compared with the concentration of the total phenol in blueberry fruit juice without enzyme treatment.3. The best fermentation conditions to braw blueberry wine determined by one factor test were founded as fermentation temperature at20℃, added sugar concentration as14%, inoculation quantity as5%. The concentration of anthocyanin and total phenol during blueberry wine alcohol fermentation decreased, the content of anthocyanin decreased253.27mg/L, as the loss percentage was33.18%; the content of total phenol decreased665.30mg/L, as the loss percentage was24.46%. Correaltion analysis showed that the O2-and-OH inhibition had significant linear relationship with the content of total phenols, the correlation coefficients were0.9414and0.9566respectively; and also had some linear relationship with the content of anthocyanin,the correlation coefficients were0.7943and0.8076.4. Using the solid phase micro extraction (SPME) combined with gas chromatography-mass spectrometry (GC/MS) in order to detect volatile flavor compounds in fermented Blueberry wine. Most of flavor substances were alcohols, acids, esters, aldehydes, and some aromatics. There were49kinds of flavor compounds identified from blueberry juice, while34kinds of flavor compounds identified from blueberry wine. There were13kinds same flavor compounds in both juice and wine,but the contents of which were different. Main flavor compounds of blueberry wine were Phenylethyl Alcohol, Linalool,3,4/2,6-dimethyl-Benzaldehyde, Hexadecanoic acid,1,3-Butanediol,2-ethyl-1-Hexanol.5. Fermentation processes of Blueberry wine were researched. Fermentation process: Blueberry→thawing→beating→enzymolysis→centrifuge→juice→mixing→inoculation fermentation→aging→primary filtration→membrane filtration→bottling.Main technical parameters:Add0.3%pectinase enzymolysis and compound pectinase, enzymolysis3.5h in45℃; To the blueberry juice,adding sugar concentration as14%, inoculation quantity as5%, adding potassium metabisulfite0.075g/L and fermentation at20℃, when the residual sugar concentration decreased to4g/L, cooled to15℃-18℃aging for several months. The Physicochemical indices and the sensual evaluations of blueberry wine were as follows:residual sugar concentration was3.75g/L, pH at3.18, total acidity with8.68g/L, alcoholic strength was12.00%(V/V), thecontent of anthocyanin was521.50g/L, the content of total phenol was1601.01mg/L and T-AOC of wine was113.57U/mL. The wine was deep red in colour, looked clear, sweet and sour, with honest, full-bodied, pleasing, generous smell of fruit flavor and bouquet.