Optimization Of Fermentation Process And Metabolite Analysis Of Dianhong Rose Grape Complex Jiaosu

Yunnan’s local Dianhong rose and Jufeng grape are used as raw materials,a variety of lactic acid bacteria were added for compound fermentation to prepare Jiaosu,the fermentation process was optimized and their antioxidant properties in vitro were measured,and the changes of differential metabolites before and after fermentation were analyzed by metabolomics.In order to improve the utilization rate and utilization value of raw materials,and provide a certain theoretical basis for their development and application.The main research contents and results of this project are as follows:(1)Yunnan Dianhong rose and Jufeng grape as raw materials,polyphenol content and Brix as indicators,the single-factor test combined with orthogonal test was designed to obtain the optimal enzymatic hydrolysis process conditions.The results showed that the optimal process conditions for enzymatic hydrolysis of complex enzymes were:ratio of complex enzyme(cellulase: pectinase): 1:3,compound enzyme addition amount: 0.6%,enzymatic hydrolysis temperature: 65°C,enzymatic hydrolysis time: 2h.(2)Response surface optimization fermentation process: on the basis of enzymatic hydrolysis process,taking SOD enzyme activity and total antioxidant activity as indicators,the optimal fermentation process conditions are: compound bacteria ratio:1:3,compound bacteria inoculation amount: 0.08%,fermentation temperature: 35°C,fermentation time: 33 h,and the polyphenol content under this condition is(2.49±0.1)mg/m L.The SOD enzyme activity was(340.88±10.25)U/m L,and the total antioxidant capacity was(77.52±0.89)umol/m L.(3)Physical and chemical and microbiological indexes of flower and fruit complex enzymes: p H value was(3.25±0.2),total acid content was(256.50±2.26)g/L,total sugar content was(148.83±3.87)mg/m L,soluble solids were(16.10±0.0)%,total lactic acid bacteria were(7.86×108)CFU/m L,and the health indicators were in line with T/CBFIA 08003-2017 "edible plant jiaosu" standard.Physical and chemical and microbiological indexes of flower and fruit complex enzymes: p H value was(3.25±0.2),total acid content was(256.50±2.26)g/L,total sugar content was(148.83±3.87)mg/m L,soluble solids were(16.10±0.0)%,total lactic acid bacteria were(7.86×108)CFU/m L,and the health indicators were in line with T/CBFIA 08003-2017 "edible plant jiaosu" standard.(4)In vitro antioxidant results of compound Jiaosu: the reducing ability of Yunnan red rose complex enzyme was enhanced,the DPPH free radical scavenging ability was91.29%,the ABTS·+ free radical scavenging ability was 88.52%,and the hydroxyl free radical scavenging ability was 78.52%.The antioxidant capacity is improved after fermentation.(5)Metabolomic analysis before and after fermentation of complex Jiaosu:metabolomic analysis of flower and fruit fermentation broth,and detection of fermentation broth by UPLC-Q-TOF-MS/MS,a total of 234 positive ion modes and146 negative ion modes of known differential metabolites were detected,including 10 types of differential metabolites,mainly including alkaloids and their derivatives,organic acids and their derivatives,organic oxygen compounds,lipids and their molecular substances,polyphenols,etc.Through pathway enrichment analysis,it was found that there were three pathways that were significant,all of which were carbohydrate metabolism pathways.Compared with before fermentation,ascorbic acid,anthocyanins,flavonoids and flavonols,folic acid,catechols,α-linolenic acid,and alkaloids in enzymes increased.