Study On Fermentation Microflora And Functional Components Of Shaoxing Traditionally Handmade Rice Wine

The Shaoxing traditionally handmade rice wine is unique in quality and flavor,and its brewing technology is a cultural heritage.The traditionally handmade rice wine produced by COFCO Kong Yiji Wines Co.,Ltd.（ZL-THRW）is brewed by a rice-spreading method,with high-quality rice wine as starter and wheat Qu as saccharifying agent.In this paper,the brewing process parameters of ZL-THRW in spring were collected,and the stability and succession mechanism of brewing microflora were clarified.At the same time,through the comparison with the large-scale fermentation tank mechanism Shaoxing rice wine,the characteristics of the nutritional and functional components of ZL-THRW were clarified,and the functions of the representative components were analyzed.Finally,the effect of wine age on the dynamic changes of functional components in ZL-THRW was analyzed.The results of this study could support the process standardization and quality control,nutrition and health value discovery and enterprise brand building of Shaoxing traditionally handmade rice wine.The research results are as follows:（1）By analyzing the brewing process parameters of ZL-THRW in spring,it was found that when the lactic acid bacteria reached a stable high density(10⁹-10¹⁰CFU/m L),the end of rice soaking was about to come.In the fermentation stage,the total acid content remained between 5.5-6.0 g/L after reaching a high level,while the number of yeasts increased to 3.6-3.8×10⁸CFU/m L and then decreased to0.64±0.38×10⁸CFU/m L.At the end of fermentation,the total sugar content was3.35±0.36 g/L,and the alcohol content reached 18.4±0.15%vol.（2）The microflora of ZL-THRW fermentation was studied by high-throughput sequencing technology.Theαdiversity analysis revealed obvious succession of microflora structure during fermentation.The results showed that the diversity of the fungal flora increased at first and then decreased,while the diversity of the bacterial flora continued to increase as the fermentation progressed.In the brewing process,Ascomycota was the absolutely dominant fungal phylum.Saccharomyces,Aspergillus and Thermomyces were the dominant fungal genera.Among them,the relative abundance of Saccharomyces was always the highest.Firmicutes,Actinobacteria,Proteobacteria and Cyanobacteria were the main bacterial phylum.Saccharopolyspora,Lactobacillus,Staphylococcus and Bacillus were the main bacterial genera,of which Saccharopolyspora accounted for the highest proportion.The characteristics of ZL-THRW brewing microflora are simple and stable fungal flora composition and Saccharopolyspora as the basic bacteria of bacterial flora.（3）Analyzing the interaction between the members of the flora in the ZL-THRW brewing process,it was found that there was a strong competitive relationship between Saccharomyces and other fungal genera.Except for Saccharomyces,other fungal genera were positively correlated.Saccharopolyspora was negatively correlated with Lactobacillus,Pediococcus,Leuconostoc and Saccharomyces,especially with a strong competitive relationship with Lactobacillus.Lactobacillus was negatively correlated with fungal and bacterial genera except Saccharomyces.The"fluctuating balance relationship"between Saccharomyces and Aspergillus was the mechanism for the microflora to maintain balance and orderly succession.In addition,Saccharopolyspora played a role in stabilizing the bacterial flora.The results of functional prediction showed that the bacterial flora was fully involved in the metabolisms of amino acids and carbohydrates,while the fungal flora was mainly involved in the metabolic pathways related to ethanol synthesis（4）Based on targeted metabonomics technology,132 components were identified in the five-year-old ZL-THRW（ZL-5）.Comparison and analysis of the nutritional and functional components of ZL-5 and five-year-old large-scale fermentation tank mechanism SRW（GYLS-5,KJS-5）found that the number of significantly different metabolites in KJS-5 vs ZL-5 and GYLS-5 vs ZL-5 two groups was 25 and 18,respectively.By comparing the differences of flavonoid components,it was found that Shaoxing traditionally handmade rice wine had stronger ability to generate and accumulate flavonoids than the large-scale fermentation tank mechanism SRW.（5）Considering the functions comprehensively,13 representative functional components were screened from ZL-THRW,and their functions were analyzed based on omics database.Through target prediction,a"component-target"network was constructed,and a total of 295 nodes were obtained,including 11 functional components and 284 targets.The 284 targets mainly act on neuroactive ligand-receptor interactions,cancer pathways,nitrogen metabolism,serotonergic synapses,PI3K-Akt signaling pathways,c AMP signaling pathways,etc.（6）Based on high-throughput targeted metabolic spectrum analysis,132components were identified in the ZL-THRW（ZL-3,ZL-5,ZL-9）of different wine ages.Comparison and analysis of ZL-THRW in different wine ages revealed that the number of significantly different metabolites in ZL-5 vs ZL-3,ZL-9 vs ZL-5 and ZL-9 vs ZL-3 three groups was 18,24 and 25,respectively.Comparing the functional components in ZL-THRW of different wine ages,it was found that the contents of flavonoids,hordenine,nicotinic acid,taurine,γ-aminobutyric acid,5-aminopentanoic acid and butin increased with the growth of wine age,while the content of epigallocatechin continued to decrease.The contents of nicotinamide,p-coumaric acid,ferulic acid and biochanin A showed a trend of increasing at first and then decreasing,whlie the content of L-carnitine showed a trend of decreasing at first and then increasing.