Study On The Brewing Technique And Component Analysis Of Wild Jujube Vinegar

Wild jujube is a natural substance of homology of medicine and food for it is rich innutrition, which contains a large quantity of sugar, vitamin, organic acid, minerals and soon. Wild jujube can be brewed into fruit vinegar, which not only can solve a lot of wildjujube seed processing wastes that caused environmental pollution and resource-wastedproblems, but also promote the added value of wild jujube processing, and enhance thedevelopment of the wild jujube industry.Wild jujube fruit vinegar brewed from wild jujube using fermentation was studied inthis thesis, including pre-processing technology, optimization of fermentation conditions,evaluation of the fermented wild jujube vinegar and analyzing flavor compositions of thefermented wild jujube vinegar, which could be a theoretical support for the deeplyprocessing of wild jujube vinegar and its industrialization.The main research techniques and the results are as follows:(1)Three juice-extraction methods (hot-extraction, fresh-extraction andenzyme-extraction) were studied. Results showed that the enzyme-extraction was thebest juice-extraction technology. Optimization of enzyme-extraction conditions werefurther studied and results showed that the ratio of material to water was1:4, dose ofpectinase was0.1%, temperature of pectinase reaction was45℃, time of pectinasereaction was3h, the reducing sugar content of wild jujube could be reached to9.03g/100ml when extracted under optimal conditions.(2)The technical conditions of liquid-solid vinegar fermentation were studied. Theresult showed that the optimum conditions for liquid state alcohol ferment method wereat sugar15%, temperature30℃, inoculum concentration0.08%, PH3.5, diammoniumhydrogen phosphate4g/L. And for solid state vinegar ferment method were at initialalcohol8.00%, the ratio of bran to rice shell3:1, inoculum concentration0.1%,temperature32℃.(3)Healthy compositions wild jujube vinegar were analyzed. Compared with jujubevinegar, persimmon vinegar, Zhenjiang balsamic vinegar and Huaimao vinegar, totalpolyphenols，total flavonoids，Vc, the components of organic acids and oxidationresistance were analyzed. The total phenolic content of wild jujube vinegar was466.88mg/100mL, which was much higher than other five kinds; the total flavonoids 152.8mg/100mL and the rate of DPPH radical scavenging90.5%that were only less thanZhenjiang vinegar, far higher than the other four kinds; Superoxide anion scavengingactivity98, that was the most effective in the six kinds of vinegar; Wild jujube vinegarwas not only rich in organic species, but each kind of organic acid content also higher.(4)39kinds of flavor substances in the wild jujube fruit vinegar were identified byGC/MC menthod. In the flavor components, acids accounts for59.43%,alcohols7.27%,aldehydes19.97%,esters9.27%, ketone0.93%，phenols0.3%and the other flavorcomponents2.74%.