Analysis of the correlation between microbial community succession and volatile flavor compounds during the processing of Gannan Yak Qula.

Flavor remodeling in Paocai during round spontaneous fermentation: an integrative analysis of active microbial succession and metabolic processes.

Correlation between microbial communities and volatile flavor compounds in the fermentation of new pickle fermentation broth

Flavor formation and microbial community dynamics in Dong ethnic fermented Anyu.

Analysis of fermentation characteristics in fermented grains across seven rounds of sauce-flavored Baijiu: Microbial communities structure, physicochemical parameters, volatile and non-volatile flavor compounds.

This study utilized headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS) to identify the key volatile flavor compounds in fermented alfalfa. The contribution of core microbiota to forming these key flavor compounds was investigated using a combination of absolute quantification of 16S rRNA gene copy number and metagenomic technology. Additionally, the critical roles of core fermentation microorganisms were quantitatively detected and validated through liquid chromatography mass spectrometry (LC-MS). Results revealed that Lactiplantibacillus plantarum B90 treated group achieved superior fermentation quality, with esters and aldehydes being the dominant volatile flavor compounds. Phenethyl acetate was the only aromatic ester that was significantly up-regulated after fermentation. The aryl alcohol dehydrogenase from L. plantarum facilitated the conversion of phenylacetaldehyde into phenylethyl alcohol, which serves as the precursor for phenethyl acetate. Furthermore, fermented alfalfa sprayed with phenethyl acetate was associated with increased feed intake in sheep. These findings propose new insights for microbial modulation of fermented flavor in fermented forage to enhance sheep feed intake.

In this study, the microbial diversity in Tibetan flavor Daqu was analyzed based on single molecule real-time sequencing (SMRT). The volatile flavor compounds in Daqu were detected using the headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). In addition, the correlation between various microbes and volatile flavor compounds was explored. Our studies indicated that the dominant bacterial genera in Tibetan flavor Daqu were Oceanobacillus, Kroppenstedtia, Virgibacillus, Enterococcus, Pediococcus, Streptomyces, Saccharopolyspora, Leuconostoc, uncultured_bacterium_f_Lachnospiraceae and Lactobacillus. The dominant fungal genera were Wickerhamomyces, Monascus, Aspergillus and Rhizomucor. 101 volatile compounds were detected in the Daqu samples, including alcohols, acids, esters, aldehydes, hydrocarbons, ketones, ethers, aromatics and pyrazines, and 10 key flavor compounds were identified using the relative odor activity value (ROAV). The results of our correlation analysis showed that Enterococcus was mainly associated with the synthesis of aldehydes such as trans-2-octenal, and uncultured_bacterium_f_lachnospiraceae was associated with the synthesis of most aldehydes. This paper has systematically investigated the physicochemical indices, microbial community structure and flavor compounds of Tibetan flavor Daqu, which is helpful in gaining a deeper understanding of the characteristics of Tibetan flavor Daqu.

ABSTRACTIn order to reveal the changes in microbial communities and volatile flavor compounds during the fermentation process of cabbage kimchi and the correlation between them, high‐throughput sequencing (NGS) and headspace solid‐phase microextraction gas chromatography–mass spectrometry (HS‐SPME/GC–MS) were used to study the microbial diversity and volatile flavor components of kimchi on Days 1, 3, 5, 7, 9, and 10 of fermentation. The correlation between microbial diversity and volatile flavor compounds was also analyzed in detail. The results showed that, in the microbial analysis of kimchi, 115 bacterial genera were identified, including Lactiplantibacillus, Bacillus, Staphylococcus, and Tetragenococcus, among others. The average relative abundance of Lactiplantibacillus was 23.44%, making it the most predominant bacterial genus in kimchi. Additionally, 176 fungal genera were identified, including Membranomyces, Aureobasidium, Scedosporium, Neomicrosphaeropsis, Phallus, and Saccharomycopsis, among others. Membranomyces had the highest average relative abundance at 85.63%, making it the most abundant fungal genus in kimchi. In the analysis of volatile flavor compounds in kimchi, 102 volatile compounds were detected, including methanethiol, linalool, and α‐pinene, etc. The average relative content of acetic acid was 6.76%, and the average relative content of dimethyl disulfide was 7.32%, making them the highest among the volatile flavor compounds detected. Alcohols and sulfur‐containing compounds were the main volatile flavor compounds. According to the correlation analysis using SPSS, 18 bacterial genera showed a strong positive correlation with volatile flavor compounds, and 15 fungal genera showed a strong positive correlation, with correlation coefficients > 0.9. The correlation analysis indicated that Lactiplantibacillus, Bacillus, Staphylococcus, and Tetragenococcus are the core bacterial genera responsible for producing key volatile flavor compounds in kimchi, while Membranomyces, Aureobasidium, Scedosporium, Neomicrosphaeropsis, Phallus, and Saccharomycopsis are the core fungal genera.

Effect of temperature on the quality and microbial community during Daocai fermentation

As a traditional fermented food, Aspergillus-type Douchi develops its characteristic flavor through natural fermentation in a semi-open environment. However, the extensive production methods traditionally employed for Aspergillus-type Douchi often result in inconsistent quality and increased contamination risks. This study utilized headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography-mass spectrometry and high-throughput sequencing techniques to elucidate the dynamic succession of volatile flavor compounds and microbial communities during the fermentation of Aspergillus-type Douchi. The results demonstrated that the total organic acid content increased steadily from 23.33 mg/g to 64.03 mg/g, predominantly comprising succinic acid, lactic acid, and citric acid. Free amino acid levels exhibited an initial rise followed by a decline, with umami amino acids consistently dominating. Alcohols, esters, aldehydes, and acids were the predominant flavor compounds in Aspergillus-type Douchi, with 36 identified as key volatile flavor compounds (VIP >1, p < 0.05). In the microbial community, bacterial communities dominated by Firmicutes, Proteobacteria, and Bacteroidota were the principal fermenting microbiota, whereas fungal communities were predominantly composed of Ascomycota. Correlation analysis results indicated that pH and total acidity were the primary environmental factors influencing bacterial communities, while amino acid nitrogen significantly impacted fungal communities. Furthermore, Corynebacterium, Bacteroides, Wickerhamomyces, Bacillus, Lactobacillus, and Staphylococcus exhibited highly significant positive correlations with at least four key volatile flavor compounds, suggesting their roles as core functional microbiota shaping the distinctive flavor profile of Aspergillus-type Douchi. This research provids a theoretical foundation for targeted quality control and the screening of novel fermentation cultures for Aspergillus-type Douchi.

To elucidate the significant influence of microorganisms on geographically dependent flavor formation by analyzing microbial communities and volatile flavor compounds (VFCs) in cigar tobacco leaves (CTLs) obtained from China, Dominica, and Indonesia. Microbiome analysis revealed that the predominant bacteria in CTLs were Staphylococcus, Aerococcus, Pseudomonas, and Lactobacillus, while the predominant fungi were Aspergillus, Wallemia, and Sampaiozyma. The microbial communities of CTLs from different origins differed to some extent, and the diversity and abundance of bacteria were greater than fungi. Metabolomic analysis revealed that 64 VFCs were identified, mainly ketones, of which 23 VFCs could be utilized to identify the geographical origins of CTLs. Sixteen VFCs with OAV greater than 1, including cedrol, phenylacetaldehyde, damascone, beta-damascone, and beta-ionone, play important roles in shaping the flavor profile of CTLs from different origins. Combined with the correlation analysis, bacterial microorganisms were more closely related to key VFCs and favored a positive correlation. Bacillus, Vibrio, and Sphingomonas were the main flavor-related bacteria. The study demonstrated that the predominant microorganisms were essential for the formation of key flavor qualities in CTLs, which provided a theoretical reference for flavor control of CTLs by microbial technology.Key points• It is the high OAV VFCs that determine the flavor profile of CTLs.• The methylerythritol phosphate (MEP) pathway and the carotenoid synthesis pathway are key metabolic pathways for the formation of VFCs in CTLs.• Microbial interactions influence tobacco flavor, with bacterial microorganisms contributing more to the flavor formation of CTLs.Graphical

The biological origin of ketotic dicarboxylic aciduria: In vivo and in vitro investigations of the ω-oxidation of C 6–C 16-monocarboxylic acids in unstarved, starved and diabetic rats

Natural sun drying process of Rugao sausage: Microbial community succession and its crucial role in flavor development.

Xuanwei ham is a traditional fermented meat product in China with a unique production process and excellent-quality reputation at home and abroad. To reveal the microbial community succession of Xuanwei ham at different post-ripening times (W1-4) and its relationship with flavour formation, the microbial community, free amino acids, and volatile flavour compounds (VOCs) were analysed by high-throughput sequencing, liquid chromatography (LC), and gas chromatography–mass spectrometry (GC-MS), respectively. A total of 25 free amino acids were detected, among which W3 contained the fewest, and most were generally lower than in hams in the other three years. Fifty-nine VOCs were detected, among which 17 were esters, and the highest ester content was found in W4. Analysis of the bacterial community composition revealed that the bacterial community composition of ham samples from W3 and other years differed greatly, and at the gate level, the dominant bacterial group of Xuanwei ham from different years was Pseudomonadota. At the genus level, the most abundant genera in W1, W2, and W4 were all dominated by Sarocladium, Klebsiella, and Vibrio, with Klebsiella being the most abundant in W1. The most abundant genus in W3 was Vibrio, and the second most dominant genera were Sarocladium and Gammaretrovirus. In short, this study provides a theoretical basis for the storage, quality, and improvement of Xuanwei ham.

Flavor perception plays a decisive role in consumer choice of dairy products. For overall flavor formation, far less is known about the specific sensory aspects of critical flavor compounds, particularly for fermentation aroma and off-flavor perception. We resolved the volatile flavor compounds produced in dairy products under a prolonged fermentation process with Lactobacillus casei or Lactobacillus bulgaricus, and 49 and 47 volatile flavor compounds, respectively, were identified by using the headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Chemometrics combined with odor activity value (OAV) calculations identified 7 key flavor components (OAV > 1). Correlations between sensory attributes and flavor components were then investigated and market validation revealed the role of 2 compounds, linalool and shiitake alcohol, in conferring fermentation aroma and off-flavor perception, respectively. Overall, these results provide a potential target for the detection and development of high-quality dairy products and provide an example for the exploration of specific sensory flavor compounds in the food industry.

A metabolomics-based approach investigates volatile flavor formation and characteristic compounds of the Dahe black pig dry-cured ham