The Research Of Blueberry Vinegar Optimum Fermentation Conditions And Anti-oxidation Activity

Blueberry,a well-known popular fruit,has been recognized by the International Food and Agriculture as "one of the five human health food." Blueberry are rich in nutrient composition which are high in anthocyanin,superoxide dismutase,polyphenols,flavonoids and other major active substances,that are known to have anti-cancer effect,anti-aging,enhance of immunity,eyesight protection and other health benefits.Till now,statistic has shown that blueberry sales increased for the pass few years including all kinds of blueberry added products such as blueberry wine,blueberry cakes,yogurt,also contributed to the fruit industry economic development.Blueberry fruit vinegar is produced by microbial fermentation,divided into two stages consist of alcohol fermentation and acetic acid fermentation.Blueberry fruit vinegar not only has nutrients from its fruit,but also its various nutritional health benefits.Hence,with increasing public health awareness,blueberry fruit vinegar will have a very good future development prospects.In this study,blueberry fruit was used as raw material,and the yeast fermentation was carried out after inoculation.The optimum fermentation conditions of blueberries were then determined and with that,blueberry fruit inoculated with activated acetic acid bacteria for acetic acid fermentation to obtain blueberry fruit vinegar.The physical and chemical properties of blueberry fruit vinegar were determined and the sensory score was carried out.Finally,the optimum acetic acid fermentation conditions were determined according to the test results.Then the antioxidant properties of blueberry fruit vinegar were analyzed.The free radical scavenging experiments including DPPH,· OH,and O2-were determined in comparison with commercially available apple cider vinegar and fruit vinegar.The results are as follows:1.The optimum alcoholic fermentation temperature is 20 ?,sugar content is 16%,yeast is Fermivin yeast.Under these conditions,when the alcohol content reached 5-6%,pressure will be applied follow by filtration,termination of fermentation.The wine shown bright dark red,its alcohol is relatively easy to control,suitable for subsequent acetic acid fermentation..2.The optimum acetic acid fermentation conditions for fruit vinegar is at the temperature of 35 ?,with DIFA acetic acid bacteria,inoculation amount of 10%.Under this condition,the fermentation of blueberry vinegar is bright and clear,sweet and sour.3.Most suitable raw materials identified:cultivated blueberries.First,several major nutrient components in wild and cultivated blueberry were tested.The results showed that the content of total acid,reducing sugar,amino nitrogen and other physical and chemical index and sensory evaluation were higher in the fruit vinegar cultivated with cultivated blueberries.The results showed that the free radical-scavenging rate of blueberry vinegar was DPPH:51.40%;·OH:76.30%;· O2-:27.80%;higher than commercial apple vinegar and vinegar.Hence,brewing blueberry fruit vinegar in the given condition will yield good antioxidant capacity.