Study On Jujube Vinegar By Mixed Fermentation

Chinese jujube has been highly valued as a medicinal plant and food,which is nutrition-rich and contains a variety of functional components.Chinese jujube is as raw material to produce fruit vinegar,which is with nutrition,flavoring and health care functions.That it may not only improve the added value of processing,but also increase the varieties of fruit vinegar in the market,Hence,development of jujube vinegar is important.In this study,Xinjiang's high-quality jujubes were used as raw materials,the process of brewing jujube fruit vinegar with mixed fermentation was explored,and the quality and flavor of jujube fruit vinegar were analyzed.On this basis,jujube fruit vinegar beverages were developed,it is expected to provide a theoretical reference for the research and development of my country's jujube fermented deep-processed products.The main research results were as follows:(1)The single factor,the fermentation process of jujube vinegar was optimized by single factor,orthogonal test and response surface design method.The optimum fermentation condition s of special yeast SY for fruit wine were as follows: fermentation time 32 h,fermentation temperat ure 28 ?,inoculum 8%.The best fermentation conditions of Lactobacillus plantarum GIM1.191 are fermentation time 24 h,fermentation temperature 32 ?,inoculum 6%.The alcohol fermentati on process needs to set the process conditions as follows: fermentation temperature 29 ?,initial sugar content 14%,inoculum size 7%(fruit wine special yeast SY: Lactobacillus plantarum GIM1.191 is 1:3),at this time the alcohol content is the highest.(2)The contents of soluble solids,protein,total sugar and reducing sugar in alcohol stage an d acetic acid stage were lower than those in red jujube juice,and the contents of total flavonoids a nd total phenols in jujube vinegar were higher.14 free amino acids were detected in jujube vinega r,of which 6 were essential amino acids.Based on gas chromatography-mass spectrometry(Gasch romatography-massspectrometry,GC-MS),a series of volatile components in jujube vinegar wer e analyzed in detail.Statistics of 26 kinds of esters.There are 16 kinds of acids,14 kinds of alcoho ls,9 kinds of aldehydes,5 kinds of phenols and 6 kinds of ketones,but only 2 kinds of ethers.Fina lly,91 kinds of compounds were identified.(3)The best jujube vinegar beverage formula was jujube vinegar 12.14%,jujube juice13.38%,sucrose 1.92% and citric acid 1.49% through the single factor-response surface experiment design method.The physicochemical and microbial indexes of jujube vinegar and jujube vinegar beverage were in line with the standards of GB 18187-2000 and GB 2719-2003.