Dynamic changes in microbial communities and flavor during different fermentation stages of proso millet Baijiu, a new product from Shanxi light-flavored Baijiu
Ontology highlight
ABSTRACT:
SUBMITTER: Zhao J
PROVIDER: S-EPMC10839113 | biostudies-literature | 2024 Jan
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Pit fermentation is the critical stage for flavor formation in sauce-flavored Baijiu (SFB). This study aimed to elucidate the fermentation characteristics in fermented grains at the start (EP) and at the end (OP) of pit fermentation across seven rounds of SFB. Kroppenstedtia and Issatchenkia gradually replaced Pseudomonas and Pichia in EP, while Lactobacillus and Issatchenkia maintained dominance in OP. In both groups, volatile flavor compounds (VFCs) and moisture contents initially increased and then declined, non-volatile flavor compounds (N-VFCs) and starch contents overall decreased, and acidity, reducing sugar, and organic acid levels generally increased. Additionally, the VFC and N-VFC contents consistently increased from EP to OP within each round. Correlation analysis revealed Issatchenkia, Kroppenstedtia, Monascus, Virgibacillus, and Pichia significantly contributed to flavor compound. Finally, a metabolic network was constructed to predict microbial and flavor compound metabolic pathways. This study provided insights into the fermentation characteristics of SFB from a multi-dimensional perspective.
| S-EPMC11833407 | biostudies-literature
Project description:This study investigated the structure and quality characteristics of hard and crispy parched rice obtained from raw proso millet through steaming, roasting, and milling. Results showed that thermal treatment disrupted the structure of samples and transformed the crystal from A-type in raw proso to V-type in parched rice. Rheological and thermodynamic analyses revealed that thermal treatment reduced the stability of parched rice. Gelatinization tests demonstrated that the parched rice was easier to gelatinize and had a lower viscosity. The digestibility of hard parched rice and crispy parched rice improved, with rapidly digestible starch content increasing by 73.62% and 76.95%, respectively, compared with that of raw proso millet. Headspace solid-phase microextraction/gas chromatography-mass spectrometry results further indicated that thermal treatment enhanced the flavor substances of parched rice. These findings demonstrated the unique properties of parched rice and supported its production and processing as a whole grain.
| S-EPMC10534107 | biostudies-literature
Project description:Light-flavor Baijiu (LFB) fermentation is a representative spontaneous mixed-culture solid-state fermentation process in which sorghum is used as the raw material. Raw materials and microorganisms are crucial to the flavor formation and quality of LFB. However, the microbial and physicochemical dynamics of different sorghum varieties during LFB fermentation, as well as their impact on flavor compounds are still largely unknown. Herein, PacBio single-molecule real-time (SMRT) sequencing and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were applied to investigate microbial community succession and volatile flavor formation in glutinous/non-glutinous sorghum-based fermented grains during LFB fermentation. Fermented grains made of glutinous sorghum Liangnuo No. 1 (GLN) had higher bacterial α-diversity and lower fungal α-diversity than those with fermented grains prepared with non-glutinous red sorghum (NRS) (p < 0.05). The dominant microbial species were Saccharomyces cerevisiae, Acetobacter pasteurinus, and Lactobacillus helveticus, the latter two of which were the predominant bacteria observed at the end of fermentation in GLN and NRS, respectively. Moisture content and reducing sugar had a more significant impact on the microorganisms in GLN, while amino acid nitrogen, total free amino acids, and residual starch were the main driving factors driving the microbial community in NRS. The correlation network and discriminant analysis indicated that a relatively high content of 4-vinylguaiacol showed a significant positive association with significant differential microbial species in GLN. These results provided valuable insights for improving the quality of LFB.
| S-EPMC11322492 | biostudies-literature
Project description:Sauce-flavor Baijiu is representative of solid-state fermented Baijiu. It is significant to deeply reveal the dynamic changes of microorganisms in the manufacturing process and their impact on the formation of flavor chemicals correlated with the quality of Baijiu. Sauce-flavor Baijiu manufacturing process can be divided into seven rounds, from which seven kinds of base Baijius are produced. The quality of base Baijiu in the third round is significantly better than that in the first and second rounds, but the mystery behind the phenomenon has not yet been revealed. Based on high-throughput sequencing and flavor analysis of fermented grains, and correlation analysis, the concentrations of flavor chemicals in the third round of fermented grains were enhanced, including esters hexanoic acid, ethyl ester; octanoic acid, ethyl ester; decanoic acid, ethyl ester; dodecanoic acid, ethyl ester; phenylacetic acid, ethyl ester; 3-(methylthio)-propionic acid ethyl ester; acetic acid, phenylethyl ester; hexanoic acid, butyl ester, and other flavor chemicals closely related to the flavor of sauce-flavor Baijiu, such as tetramethylpyrazine. The changes in flavor chemicals should be an important reason for the quality improvement of the third round of base Baijiu. Correlation analysis showed that ester synthesis was promoted by the bacteria genus Lactobacillus and many low abundances of fungal genera, and these low abundances of fungal genera also had important contributions to the production of tetramethylpyrazine. Meanwhile, the degrading metabolic pathway of tetramethylpyrazine was investigated, and the possible microorganisms were correlated. These results clarified the base Baijiu quality improvement of the third round and helped to provide a theoretical basis for improving base Baijiu quality.
| S-EPMC9818360 | biostudies-literature
Project description:Shanxi broomcorn millet Huangjiu (SXHJ) is a typical representative of northern Huangjiu. This study employed high-throughput sequencing and untargeted metabolomics to conduct an in-depth analysis of the key aroma components and microbial community during the traditional fermentation process of SXHJ. The research identified 16 amino acids and 72 key aroma compounds, with a wide variety of esters and a high concentration of alcohols. Weissiella, Enterococcus, Paucibacter, Saccharomyces, Aspergillus, Candida, Mortierella, Pichia, Hygrocybe, Thermoascus, and Clavispora were identified as core microorganisms. Notably, certain specific microorganisms, such as Weissella and Saccharomyces, were found to be strongly associated with the production of specific aroma compounds. Further analysis revealed a significant correlation between bitter amino acids and most microorganisms, with the exception of Pichia and Limosilactobacillus, suggesting unique interactions among microorganisms during fermentation. These insights are instrumental in guiding the regulation of SXHJ aromatic properties.
| S-EPMC11915025 | biostudies-literature
Project description:Baiyunbian baijiu, the most popular miscellaneous-flavor baijiu in China, has been widely consumed for decades. Similar to many Chinese baijiu, Baiyunbian baijiu is fermented in five successive batches every year. Sensory analysis demonstrated that the raw baijiu obtained from the last two fermentation batches always has better quality than that produced from the former three batches. In this study, the microbial compositions of fungi and bacteria in each fermentation batch were investigated via high-throughput sequencing. The results showed that Bacillus, Virgibacillus, and Lactobacillus dominated the bacterial community in the last two batches, and the most prevalent fungi were Paecilomyces, Saccharomyces, and Zygosaccharomyces. In contrast, large percentages of fungi belonging to Thermomyces, Thermoascus, Monascus, and Issatchenkia and prokaryotes belonging to Acetobacter, Lactobacillus, and Thermoactinomyces were observed in the former three fermentation batches. GC-MS analysis revealed that the fermented grains sampled from the latter two batches contained high concentrations of ethyl lactate, 2,3-butanediol and ethyl caproate, which were mainly generated by co-fermentation of Lactobacillus and yeast. The high acidity of the fermented grains in the fourth and fifth fermentation batches as well as the large contents of ethanol and moisture promoted the formation of the functional microbial community. This study provides insight into factors that influenced the baijiu fermentation and is helpful for developing new fermentation techniques with higher baijiu quality.
| S-EPMC7005924 | biostudies-literature
Project description:The distinct flavor of chi-flavor baijiu (CFB) has garnered significant attention in China. After the optimization of fermentation conditions, Pichia anomala and Lactobacillus plantarum were introduced into the fermentation process to enhance the flavor. Samples inoculated with these mixed strains (SY) exhibited higher levels of alcohol (from 33.04 to 178.55 mg/L) and esters (from 49.51 to 130.20 mg/L) compared to the control group (KB). In SY, P. anomala and L. plantarum were the predominant microorganisms, while Pediococcus and Saccharomyces were more prevalent in KB. Moreover, 68 volatile flavor compounds were detected in SY, as opposed to 64 in KB. Notably, Pichia showed a positive correlation with key flavor compounds. The synergistic fermentation with exogenous strains led to a 52.38% increase in phenethyl alcohol and a 4.91% increase in ethyl lactate. Additionally, the levels of other flavor compounds, like ethyl acetate, γ-nonanolactone, and (E)-2-octenal, also increased. The results demonstrated that the addition of P. anomala and L. plantarum to the fermentation process of CFB significantly increased the contents of flavor compounds. This research reveals valuable insights into flavor enhancement and the microbial community dynamics in CFB production.
| S-EPMC11545386 | biostudies-literature
Project description: Not available
| S-EPMC11926691 | biostudies-literature
Project description:Microbial structure and succession of fermented grains play a significant role in Baijiu's flavor and quality. In this study, high-throughput sequencing (HTS) coupled with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the microbial community structures and flavor components in the fermented grains at the end of fermentation from different fermentation time of light-flavor Xiaoqu Baijiu. HTS results showed that Lactobacillus acetotolerans, Lactobacillus helveticus, Lactobacillus buchneri, Wickerhamomyces, Saccharomyces, and Condenascus were identified as the dominant microbes, but Lactobacillus (96.28%) exhibited obvious advantages at the end of ultra-long fermentation time (day 98). HS-SPME-GC-MS analysis revealed that esters and alcohols had the most abundance in fermented grains of day 98, containing high concentrations of ethyl acetate, diethyl succinate, phenylethyl alcohol, isoamyl alcohol, and n-propanol, which were related to the succession of Lactobacillus and yeast communities. Interestingly, the content of n-propanol in the ultra-long fermentation time samples (day 98) was 6 times of that in normal fermented grains (day 14), which may be caused by higher abundance of Lactobacillus in day 98 samples. Monte Carlo permutation test showed residual starch, acidity, and amino nitrogen (p < 0.05) were important factors affecting the microbial community. Together, these results shed light on the physicochemical changes, microbial dynamics, and key flavor components of fermented grains at the end of fermentation from different fermentation time and provide a strategy for further improvement of Baijiu quality.
| S-EPMC8611178 | biostudies-literature
Project description:The compositions of the microbial community in fermented grains of Sauce-flavor baijiu produced in different regions have diverse characteristics; however, the reasons for this remain unclear. The present study investigated the contributions of environmental microorganisms to the microbial community as well as the volatile compounds in the fermented grains of Sauce-flavor baijiu produced in the Beijing region using high-throughput sequencing combined with sourcetracker analysis, and compared the differences of environmental microorganism and their roles in the production process of Sauce-flavor baijiu from different regions.The results showed that the environmental microorganisms in the tools were the main contributors of the bacterial and fungal communities in fermented grains during heap fermentation and at the beginning of pit fermentation. At the end of pit fermentation, pit mud was the main environmental source of bacterial community in fermented grains, while tools and Daqu were the main environmental sources of fungal community in fermented grains.Environmental microorganisms thrived on the functional microorganisms in the fermented grains of Sauce-flavor baijiu produced in the Beijing region and thus shaped the profiles of volatile compounds. Environmental microorganisms of Sauce-flavor baijiu in the Guizhou province and the Beijing region differed significantly, which is partially responsible for the distinctive characteristics in the microbial community structure of Sauce-flavor baijiu-fermented grains from different regions.
| S-EPMC9818559 | biostudies-literature