Red Jujube Fruit Vinegar And Oxidation Resistance Research

With its great nutrition, the red jujube is one kind of food and medicine,known as “the pearl of fruits”. It enjoys great popularity among people love forits strong adaptability, long life, rich nutrition and flexibility in intercroppingwith grain and cotton as well as other features. However, every year there existsthe phenomenon that a lot of inferior jujube and jujube processing waste are notfully applied for it is perishable and poor in storability, Therefore, based oncomprehensive exploration and application of thered jujube, It is proposed tofurther develop the technical methods in the jujube fermentation by conductingexperiments and research work as well as revealing secrets of active ingredientin the vinegar of fermented dates.The essay takes Ningxia Jujube and Shaanxi Jujube as the subject in thisresearch. It aims at providing evidences for jujube vinegar health functions bydetecting composition of inferior jujube and jujube pit, researching the itsbrewing processing system, while examining contents of polyphenol andflavonoid, and antioxidantfunction in the detection of jujube vinegar over jujubevinegar fermentation period. The results are as follows:The contrast made between second-class fresh jujube and excellent freshjujube shows that there are no clear differences in total sugar, total acid and finevarieties of jujube. Moreover, it is found that, among second-class dry jujube,Lingwu long jujube tops the list for its polyphenols and flavonoid contents whichare452.10mg/100g and387.42mg/100g respectively. Additionally, the researchrevealed that total saponin content was highest as387.54mg/100g.While thepolyphenol content in the Lingwu jujube pit was13.46mg/g, total flavonoidcontent was3.64mg/g and saponin content was8.41mg/g.Lingwu jujube Inferior used as raw material, with the use ofliquid-liquidshaker fermentation process, the data in jujube juice extraction technologyinclude increased amount of enzyme was0.3%, extraction temperature is50°C,extraction time5.0h, add waterfour times, the pH value of3.5. Based on single factor experiments and response surface optimization of fermentation tests, theoptimum conditions of the jujube vinegar alcohol fermentation are asfollows:fermentation temperature34°C,6%of the total inoculum size, sugar content12%Under these conditions, the ethanol content of7.01%, in which yeast: lacticacid3:1. The optimum conditions of the jujube vinegar vinegar vinegarfermentation: the fermentation temperature of33.44°C, inoculum size10.6%initial alcoholcontent of6.84, under these conditions, acetic acid content of5.14g/100mL.The pits of Ningxia jujube are used as raw materials to produce fermentedjujube pit vinegar. after the removal meats of pits, with reference to ultrasonicextraction method, optimal extraction conditions in the orthogonal experimentaldesign are as follows: concentration of ethanol70%, extraction time80min,solid-liquid ratio1:20, extraction temperature70°C, measured date pit in thepolyphenol content of13.46mg/g, and the flavonoid content of3.47mg/g; bysingle factor and orthogonal experiments to optimize thefermentation process todetermine the jujube vinegar alcoholic fermentation temperature32°C, sugarcontent14%yeast inoculum size8%of lactic acid bacteria inoculated2%, aceticacid fermentation temperature36°C,7%of the initial alcohol content,10%oftheacetic acid bacteria inoculum size, initial pH4.0. The comparisonbetweenchitosan, bentonite, PVPP cross-linked polyvinylpyrrolidone, and pectinaseclarifies that the jujube pit vinegar stays stableafter diatomaceous earth andpectinase clarification.The Lingwu round jujube and barley used as raw material, mixing ratio ofjujube fermented fruit grain vinegar is following: juice3:1, The orthogonal testto optimize the fermentation process shows composite juice alcohol fermentationtemperature is30°C, soluble solids content is16%, the wine yeast inoculation is6%, brewer’s yeast inoculum size is2%, acetic acid fermentation temperature is36°C, acetic acid bacteria inoculum is10%, the initial alcohois8%; to5%juice,2%salt,1%honey, which is to the best taste.The research on Jujube vinegar antioxidant activity, for the first timetracking polyphenol and flavonoid content in the inferiorjujube vinegar process test, shows that extraction jujube juice decreases in thehot water, jujube juice of pectinase extraction increases, polyphenol and flavonoid content decreases in the alcohol fermentation, while increases in aceticacid fermentation and agingprocess. Vinegar transmittance can reach more than93%, handled by pectinase and chitosan, the4mL chitosan added. At the sametime, polyphenol content drops to20.42mg/100mL. Falconoid content drops to6.32mg/100mL. Clarification can be achieved more than93%with pectinase8mL added. Polyphenolcontent increases to29.07mg/100mL, the flavonoidcontent increases to9.47mg/100mL. The research on free radical scavengingactivityof inferior dates fermented vinegar indicates that a clearance rate in OHis83.5%and fermented vinegar,（O₂）^-clearance rate is52.5%. The free radicalincreases with the increasing of its concentration, and parallel to the content oftpolyphenol and flavonoid in jujube vinegar.