Optimization Of Fermentation Technology And Analysis Of Primary Metabolites And Volatile Metabolites Of Red Beet Wine

Edible red beet(Beta vulgaris L.var.Cruenta Alef.),also known as red cabbage,red cabbage head,belongs to Chenopodiaceae,sugar beet genus,biennial herbs.It is a variety of cultivated sugar beet.In this study,In order to improve the added value of red beet,the red beet wine was used as the raw material for alcoholic fermentation And the fermentation process of edible red beet wine was optimized.The physicochemical indexes and in vitro antioxidant activity of edible red beet wine prepared by the optimum fermentation process were detected,and its primary metabolites and volatile metabolites were detected and analyzed.The results were as follows.1?The fermentation conditions of edible red beet wine were optimized by single factor experiment and response surface experiment.Experiments showed that the best fermentation process were as follows:0.08% for yeast inoculation amount,27.5% for initial sugar content,5.5 d for fermentation time,27 ? for fermentation temperature.Under these conditions,the alcohol content of edible red beet wine was 11.4% vol.Its physical,chemical and health indexes were in line with the national standards.2?The experiment of antioxidant capacity in vitro showed that the scavenging rates of DPPH radical,hydroxyl radical,superoxide anion and reducing power of red beet wine were 81.3%,66.8%,80.9% and 0.517 respectively with a dose-effect relationship.The results showed that red beet wine had good antioxidant activity.3?A total of 229 kinds of primary metabolites were detected in LC-MS/MS detection,including 1 kind of phosphatidylcholine,2 kinds of lysophosphatidylcholine,2 kinds of glycerides,7 kinds of vitamins,12 kinds of free fatty acids,19 kinds of sugars and alcohols,34 kinds of nucleotides and their derivatives,38 kinds of organic acids,43 kinds of phenolic acids and 71 kinds of amino acids and their derivatives.There were 140 kinds of metabolites with significant differences,89 kinds of which were up-regulated and 51 kinds of which were down-regulated.4?The cluster analysis of differential metabolites showed that the high content of in the fermentation group was more than 50%,which was significantly more than that in the control group.The contents of amino acids and their derivatives,organic acids and phenolic acids in the fermentation group were higher than those in the control group,and the content of lipids in the control group was higher than that in the fermentation group.There was no significant difference in the content of nucleic acid and its derivatives and other metabolites between the two groups.The classification and enrichment analysis of KEGG pathways of differential metabolites showed that 67 metabolic pathways were annotated.KEGG enriched analysis showed that a total of 20 pathways of significantly different metabolites was annotated.5?A total of 87 volatile metabolites were detected in GC-MS/MS detection,including 31 kinds of alkanes,1 kind of anhydride,5 kinds of acids,20 kinds of esters,1 kinds of pyrazine,4 kinds of benzene,2 kinds of alkenes,8 kinds of ketones,5 kinds of alcohols,6 kinds of aldehydes,1 kind of phenols and 3 kinds of amines.33 kinds of metabolites with significant differences were obtained,including 25 up-regulated kinds and 8 down-regulated kinds.6?The cluster analysis of differential metabolites showed that the high content of differential metabolites in the fermentation group was significantly more than that in the control group,indicating that more aroma components were formed in the fermentation process of edible red beet,in which esters,one of the main aroma substances in edible red beet wine,accounted for the largest percentage.