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. 2020 Mar 26;20(1):67.
doi: 10.1186/s12866-020-01745-3.

Effects of aging on the quality of roasted sesame-like flavor Daqu

Guangsen Fan  1   2   3 , Zhilei Fu  2 , Chao Teng  1   2   3 , Pengxiao Liu  2 , Qiuhua Wu  2 , Md Khondakar Raziur Rahman  1   2 , Xiuting Li  4   5   6
Affiliations

Effects of aging on the quality of roasted sesame-like flavor Daqu

Guangsen Fan et al. BMC Microbiol. .

Abstract

Background: Daqu, the saccharification, fermentation, and aroma-producing agents for Baijiu brewing, is prepared using a complex process. Aging is important for improving the quality of Daqu, but its impact has rarely been studied. This study investigated changes in the physicochemical properties, flavor compounds, and microbial communities during aging of Daqu with a roasted sesame-like flavor.

Results: The physicochemical properties changed continuously during aging to provide a high esterifying activity. Aging removed unpleasant flavor compounds and helped to stabilize the flavor compounds in mature Daqu. A high-throughput sequencing approach was used to analyze the changing composition of the microbial communities during aging. Aging helped to modify the microbial population to produce better Baijiu by eliminating low-abundance microbial communities and optimizing the proportion of predominant microbial communities. Nine genera of prokaryotic microbes formed the core microbiota in Daqu after aging. Regarding eukaryotic microbes, Zygomycota, the predominant community, increased in the first 2 months, then decreased in the third month of aging, while Ascomycota, the subdominant community, showed the opposite behavior. Absidia, Trichocomaceae_norank and Rhizopus were the predominant genera in the mature Daqu.

Conclusions: Significant correlations between microbiota and physicochemical properties or flavor compounds were observed, indicating that optimizing microbial communities is essential for aging Daqu. This study provides detailed information on aging during Daqu preparation.

Keywords: Baijiu; Esterifying activity; Eukaryotic microbes; High-throughput sequencing; Prokaryotic microbes; Volatile compounds.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Process flow diagram for the production of Daqu and the diagrammatic drawing of sampling for Daqu samples
Fig. 2
Fig. 2
Taxonomic classification of sequences from prokaryotic communities of four samples (A0, at the beginning of aging; A1, after 1 month of aging; A2, after 2 months of aging; A3, after 3 months of aging) at genus level. The relative abundance was calculated by dividing the number of classified tags by the total tags number of each sample. The top 50 genera detected in RSF Daqu are shown. The relative abundance of each genus was indicated by color intensity in a heat map
Fig. 3
Fig. 3
Analysis of prokaryotic communities composition in four samples (A0, at the beginning of aging; A1, after 1 month of aging; A2, after 2 months of aging; A3, after 3 months of aging) using high-throughput sequencing. Results of taxonomy at the phylum level and genus level are shown in (a) and (b), respectively. The relative abundance defines sequence percentages in samples as depicted by the colors in the bar chart. The top 20 phyla and genera detected in RSF Daqu are shown in (a) and (b), respectively. The rest of phyla and genera detected in all samples were classified as others
Fig. 4
Fig. 4
Analysis of eukaryotic communities composition in four samples (A0, at the beginning of aging; A1, after 1 month of aging; A2, after 2 months of aging; A3, after 3 months of aging) using high-throughput sequencing. Results of taxonomy at the phylum level and genus level were shown in (a) and (b), respectively. The relative abundance defines sequence percentages in samples as depicted by colors in the bar chart. The top 20 phyla and genera detected in RSF Daqu are shown in (a) and (b), respectively. The rest of phyla and genera detected in all samples were classified as others
Fig. 5
Fig. 5
Canonical correspondence analysis (CCA) of prokaryotic communities at genus level and physicochemical properties (a), and redundancy discriminate analysis (RDA) of eukaryotic communities at genus level and physicochemical properties (b) found in Daqu. Arrows represent different physicochemical properties; the symbols ■, ●, ▲, and ◆ represent samples A0 (at the beginning of aging), A1 (after 1 month of aging), A2 (after 2 months of aging), and A3 (after 3 months of aging), respectively. The tow axes explain 97.17 and 86.39% of the total variance in bacterial (DCA = 4.10) and fungal (DCA = 1.15) community differentiation, respectively
Fig. 6
Fig. 6
Correlation between volatile compounds (V1-V34: different flavor compounds in Additional file 1 Table S1) and prokaryotic communities (a) and eukaryotic communities (b) found in Daqu. Scale bar colors denote the nature of the correlation, with 1 indicating a perfectly positive correlation (read) and − 1 indicating a perfectly negative correlation (blue) between them. “*” shows significant correlations (P < 0.05), and “NA” shows no correlations
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References

    1. Pang XN, Han BZ, Huang XN, Zhang X, Hou LF, Cao M, Gao LJ, Hu GH, Chen JY. Effect of the environment microbiota on the flavour of light-flavour Baijiu during spontaneous fermentation. Sci Rep. 2018; 8(3396): http://doi.org/10.1038/s41598-018-21814-y. - PMC - PubMed
    1. Liu HL, Sun BG. Effect of fermentation processing on the flavor of baijiu. J Agr Food Chem. 2018;66(22):5425–5432. - PubMed
    1. Wang XD, Ban SD, Qiu SY. Analysis of the mould microbiome and exogenous enzyme production in Moutai-flavor Daqu. J I Brewing. 2018;124(1):91–99.
    1. Wang P, Wu Q, Jiang XJ, Wang ZQ, Tang JL, Xu Y. Bacillus licheniformis affects the microbial community and metabolic profile in the spontaneous fermentation of Daqu starter for Chinese liquor making. Int J Food Microbiol. 2017;250:59–67. - PubMed
    1. Ming HM, Zhou J, Zhu LL, Xu DF, Liu YH, Yao X. A comparative study of traditional/new daqu quality indicators system. Liquor-Making Sci Technol. 2015;4:32–36.

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