Study On The Changes Of Chemical Components And Microorganisms In The Wine Lees Pickling Process Of Zao-Ginger Based On Metabolomics And Metagenomics

Objective: Zao-ginger is made from “Crested ginger” as raw material,supplemented by chilli,garlic,Baijiu,etc.,through sealed natural grains.It is a typical raw wine lees pickling product,crisp,tender and delicious.However,the mechanism of forming the quality of zao-ginger is still unknown at present.Therefore,this paper focuses on the change law of the main microorganisms and dominant bacteria in the process of making zao-ginger,and explores the chemical composition,differential metabolites and significant differential metabolic pathways in the process of making zao-ginger,clarify the correlation between dominant microorganisms and the conventional chemical components and differential metabolites.Methods: Titration,spectrophotometer and HPLC were used to determine the changes of conventional chemical components in the wine lees pickling process of zao-ginger,and the changes of metabolites and microorganisms were determined by wide-target and macrogenome sequencing methods.Results: 1)through zao-ginger and lees solution routine chemical components flavonoids,polyphenols,reducing sugar,total sugar,gingerol,protein,the determination of total free amino acids and other indicators,in the worst within 30 days,with the wine lees pickling system is the extension of time,the different stages of system of zao-ginger and lees solution,zao-ginger p H decreased from 4.32 to 3.66,lees solution p H decreased from 4.13 to 3.30,The total acid of zao-ginger increased from4.67 g/L to 6.67 g/L,and the total acid of lees solution increased from 40.00 g/L to106.67 g/L,and the environment of wine lees pickling was acidified gradually.The sugar content drops,and the phenols gradually rise.The nitrite content was maintained within the safe range of 20 mg/kg during the whole wine lees pickling.The changes of protein and total free amino acid were similar,which increased first and then tended to be stable.HPLC analysis found that there were many kinds of polysaccharides and polyphenols in stage IV of zao-ginger and its solution,and the content was relatively rich.2)The metabonomics technology of ultra-high performance liquid chromatography tandem mass spectrometry(UPLC/MS/MS)was used to analyze the metabolic components of zao-ginger in different stages of the wine lees pickling,and the differential primary metabolites and differential secondary metabolites were finally identified.It included 12 amino acids and their derivatives,11 organic acids and their derivatives,4 sugars,24 flavonoid metabolites,19 alkaloids,20 terpenoids,10 polyphenols and phenylpropanes.The six main metabolic pathways were obtained in the five stages: metabolic pathway,biosynthesis of secondary metabolites,fructose and mannose-metabolism,galactose metabolism,phenylalanine metabolism,and zetin biosynthesis.Mapping the differential metabolites into the KEGG database,3significant metabolic pathways were obtained,including zeatin biosynthesis,aminoacyl biosynthesis and ABC transporter metabolism pathway.3)High-throughput sequencing was used to analyze the changes of bacterial and fungal communities in the different wine lees pickling stages of zao-ginger.Through the diversity index,the changes of taxonomic composition and cluster analysis,the microbial community structure in the wine lees pickling process of zao-ginger was complex and diverse.Among them,the dominant bacteria in zao-ginger were Firmicutes,Proteobacteria and actinomyces,etc.And the dominant bacteria were Lactobacillus,weisella,panomyces,etc.The dominant phylum level fungus in zao-ginger were ascomycetes,mucor,basidiomycetes and mortierellomycota,and the dominant genus level fungus were kazakhstanensis,pichia,mucor,fusarium,etc.In conclusion,there were differences in the microbial communities at different stages of zao-ginger,and the microbial relative abundance was significantly affected at different stages of zao-ginger.Conclusion: Through the correlation analysis of conventional chemical composition,metabolic composition and microbial flora in the process of distiller’s grains processing,it was found that Pantaea,Pseudomonas,Lactococcus,Lactobacillus,Mitochondria,Kazakhstan,Fusarium,Neodiopteria,Pichia has a significant effect on the conventional chemical composition and metabolic components of zao-ginger.