Search Results (999)

This study systematically analyzed the multidimensional effects of Lactobacillus fermentation on Pueraria lobata (PL) and investigated the potential mechanisms underlying its hypolipidemic activity. Results indicated that fermentation significantly increased the total acid content from 1.02 to 3.48 g·L⁻¹, representing a 2.41-fold increase. Although slight reductions were observed in total flavonoids (8.67%) and total phenolics (6.72%), the majority of bioactive components were well preserved. Other antioxidant capacities were retained at >74.71% of baseline, except hydroxyl radical scavenging. Flavor profiling showed increased sourness and astringency, accompanied by reduced bitterness, with volatile compounds such as β-pinene and trans-2-hexenyl butyrate contributing to a distinct aromatic profile. Untargeted metabolomics analysis revealed that fermentation specifically enhanced the abundance of low-concentration isoflavone aglycones, including daidzein and genistein, suggesting a compositional shift that may improve hypolipidemic efficacy. Integrated network pharmacology and computational modeling predicted that eight key components, including genistein, could stably bind to ten core targets (e.g., AKT1 and MMP9) primarily through hydrogen bonding and hydrophobic interactions, potentially regulating lipid metabolism via the PI3K-AKT, PPAR, and estrogen signaling pathways. This study reveals the role of Lactobacillus fermentation in promoting the conversion of isoflavone glycosides to aglycones in PL and constructs a multi-dimensional “components-targets-pathways-disease” network, providing both experimental evidence and a theoretical foundation for further research on the lipid-lowering mechanisms of fermented PL and the development of related functional products. Full article

The seafood industry is increasingly adopting intelligent packaging to preserve product quality and improve freshness transparency. This study developed and evaluated a pH-sensitive freshness indicator (FI) for skate sashimi (Zearaja chilensis). This product is consumed at varying stages of fermentation. The FI incorporated bromothymol blue (BTB) and bromocresol purple (BCP) in a polymer matrix. It targeted volatile basic nitrogen (VBN) compounds, with trimethylamine (TMA) as the primary marker. As freshness declined, VBN compounds accumulated in the package headspace and caused a gradual FI color change from yellow to blue through pH variation. ΔE increased from 7.72 on day 2 to 23.52 on day 3. This marked the onset of visible color change and the FI reached full blue by day 7. Headspace solid-phase microextraction (HS-SPME) and gas chromatography–flame ionization detection (GC-FID) quantified monomethylamine (MMA), dimethylamine (DMA) and TMA throughout storage. ΔE correlated strongly with total bacterial count (TBC, r = 0.978), pH (r = 0.901) and TMA (r = 0.888). These results indicate that microbial growth, alkalinity increase and amine production were closely associated with color transitions. The FI reliably tracked freshness loss in skate sashimi. It has potential to enhance consumer transparency and strengthen quality control in the seafood supply chain. Full article

Artemisia selengensis Turcz. (AST), an edible-medicinal herb, contains multifunctional bioactives. This study investigated the application of AST leaf extract (ASTLE) in beer brewing, focusing on the addition stage and its impacts on fermentation dynamics, flavor profile, and functional properties. Fermentation parameters, bioactive compounds (phenolic; flavonoid), and volatiles (using HS-SPME-GC-MS) were analyzed. In vivo efficacy was assessed in high-fat diet-fed mice supplemented for 8 weeks with beer containing 10% ASTLE (post-primary fermentation), evaluating body weight change, serum lipids, and uric acid levels. It was found that adding ASTLE before primary fermentation promoted yeast activity but increased the risk of excessive diacetyl production. Adding ASTLE after primary fermentation significantly increased total phenolic and flavonoid contents. GC-MS analysis revealed that ASTLE contributed 28 additional volatile compounds, including chrysanthenone and eucalyptol, thereby enriching the beer’s flavor profile and complexity. In mice, beer with 10% ASTLE (post-primary fermentation) reduced body-weight gain, and regulated abnormal blood lipids and serum uric acid levels. Adding ASTLE after primary fermentation optimized fermentation stability, bioactive retention, flavor enhancement, and conferred benefits including body-weight regulation, lipid metabolism improvement, and uric acid control, providing a reference for developing functional beers targeting health-conscious consumers. Full article

This study systematically investigated the effects of key fermentation parameters—initial sugar content (24–28 °Brix), temperature (15–20 °C), and yeast inoculation rate (0.04–0.12%)—on the quality, volatile aroma characteristics, antioxidant capacity, and bioactive properties of mulberry wine. Through a combination of single-factor experiments and response surface methodology (RSM), optimal fermentation conditions were determined as follows: initial sugar content of 25 °Brix, temperature of 18 °C, and yeast inoculation rate of 0.08%. Under these conditions, the resulting wine exhibited superior sensory characteristics, enhanced antioxidant activity (total phenolic content, DPPH and ABTS radical scavenging capacity, and FRAP), and significantly higher levels of key aroma compounds (e.g., ethyl acetate, phenethyl alcohol) compared to unfermented mulberry juice. Furthermore, the wine exhibited dose-dependent inhibition of proliferation in HepG2 and HT29 cells with IC₅₀ values of 0.82 mg/mL and 1.05 mg/mL, respectively, and demonstrated selective antibacterial activity against Escherichia coli and Staphylococcus aureus. These findings provide a scientific basis for optimizing the production of mulberry wine with enhanced sensory qualities and functional properties, highlighting its potential as a health-promoting fermented beverage. Full article

Fermented fruit juices are considered functional beverages because they contain bioactive compounds derived from plant materials and produced by the microorganisms involved in fermentation. The composition of these beverages can vary depending on the strain used. This study aimed to determine the effect of different microorganisms conducting lactic acid fermentation on the chemical composition and bioactive component content of naturally cloudy fermented pear and plum juices. The process used Lactiplantibacillus plantarum K7 bacteria, which were isolated during sauerkraut fermentation, as well as Lachancea thermotolerans PYCC6375 and Lachancea fermentati PYCC5883 yeast cultures, which have poor ethanol fermentation capabilities. The pH, acidity, sugars (HPLC), free amino nitrogen, selected organic acids (HPLC), color (CIELAB), polyphenols (HPLC), volatiles (GC-MS), aroma-active volatiles (GC-MS-O), and sensory characteristics were analyzed. The fermented juices obtained were rich in organic acids (of plant and microbial origin), polyphenols, and had a reduced sugar content (with polyols replacing glucose and fructose), as well as a low alcohol content (<0.2%). At the same time, all three microorganisms significantly enhanced the fruity aroma of the juices. Lachancea yeasts proved to be a viable alternative to lactic acid bacteria for producing fermented juices and were significantly better suited to fermenting plum juices. The highest polyphenol content and highest consumer preference rating were obtained with plum juices fermented with L. fermentati yeast. Full article

Pea protein yogurt (PPY), as an alternative to traditional dairy yoghurt, has the advantages of being a green raw material, lactose cholesterol-free, and adaptable to the needs of lactose-intolerant people. PPY was prepared by fermenting a mixture of pea protein and water (1:10, w/v) supplemented with 5% fructose for 10 h after heat sterilisation. During fermentation, lactic acid bacteria metabolise pea protein to produce aldehydes and other aromatic compounds, imparting a unique sweet–sour balance and mellow flavour. However, issues such as weak gel formation and prominent soybean-like off-flavours severely restrict the development and consumer acceptance of PPY. In this study, five fermentation systems were systematically investigated to elucidate the fermentation mechanisms of pea yoghurt and explore effective methods for eliminating undesirable soy flavours. The results indicated that hydrophobic interactions and disulfide bonds are the predominant forces driving gel formation in PPY. Additionally, the protein content increased by 0.81 g/100 g following fermentation. A total of 43 volatile flavour compounds—including aldehydes, alcohols, acids, ketones, and furans—were identified, among which the concentrations of hexanal and 2-pentylfuran, known markers for soybean off-flavour, significantly decreased. Furthermore, high-temperature and high-pressure treatments (121 °C, 3 min) demonstrated superior effectiveness in reducing soybean-like flavours. Although the high-temperature and high-pressure treatment, double-enzyme hydrolysis, and flavour-masking methods operate through distinct mechanisms, their flavour profiles converged, displaying substantial deodorisation effects and synergistic interactions. These findings provide a theoretical basis and processing parameters for flavour modulation in PPY; however, further formulation optimisation is required to enhance its nutritional and textural properties. PPY shows promise as a potential alternative to conventional dairy products in the future. Full article

As the core of the solid-state fermentation system, the quality of pit mud is directly determined by the synergistic effects of volatile flavor compounds, microbial communities, and abiotic physicochemical factors. However, pit mud lacks systematic knowledge, especially concerning the dynamic association mechanism and threshold effect of its three components. This results in blind spots within the pit mud metabolism regulation network, which has become a bottleneck in precise pit mud quality regulation. Focusing on the volatile flavor compounds of pit mud is crucial to exploring their association with the core microbial community and physicochemical factors of pit mud, in order to cultivate high-quality pit mud. Although a large number of studies have revealed the formation mechanism of high-quality pit mud based on the three factors and cultivated artificial pit mud through microbial enhancement or synthetic flora to improve the quality. However, anaerobic fermentation is a complex system, and the complexity and dynamics of microorganisms make it difficult for biofortification and synthetic flora to effectively regulate the quality of pit mud. Therefore, this paper reviews the research progress on flavor compounds, microbial communities and abiotic factors associated with pit mud quality, deepens the understanding of their influence on pit mud quality, and proposes a precise environmental control strategy to alter the composition and content of the microbial community in the pit mud. The key to this scheme lies in constructing a correlation network through multi-omics integration to identify the physical and chemical factors related to the quality of the pit mud. During the fermentation process, intervention measures are taken on environmental parameters, ultimately effectively changing the physical and chemical factors, thereby achieving the assumption of precise control of the quality of the pit mud. This provides necessary references and inspirations for improving the quality of pit mud, cultivating artificial cellar mud, and enhancing the quality of Baijiu. Full article

Sauce-flavor Daqu is the solid-state fermentation starter for sauce-flavor Baijiu. Its microbial community influences flavor formation, yet links between community change, process conditions, and flavor development during high-temperature fermentation remain unclear. We investigated Daqu fermentation by integrating high-throughput sequencing, monitoring of physicochemical parameters, and analysis of volatile compounds. Fermentation temperature showed three phases: rapid rise, fluctuating plateau, and gradual decline. High temperatures were associated with increased thermophilic microbes such as Bacillus and Thermoascus and with higher levels of reducing sugars and amino acid nitrogen; amylase, protease, and other hydrolase activities were detected. Bacterial composition varied more than fungal composition; Firmicutes and Ascomycota were the dominant phyla, and Bacillus and Thermoascus were abundant genera. Canonical correspondence analysis associated reducing sugars, acidity, and moisture with early community shifts, and amino acid nitrogen with later shifts; reducing sugars and moisture showed the strongest associations. Filamentous fungi and Bacillus correlated with pyrazine-type compounds. These results link microbial composition, process parameters, and flavor profiles, and may inform the standardization and mechanization of Daqu production. Full article

The development of non-alcoholic beer (NAB) with health benefits, using non-conventional potential probiotic yeasts, offers an interesting alternative to standard NAB brewing strategies. In this study, potential probiotic non-Saccharomyces yeasts Pichia manshurica, Kluyveromyces lactis, and Kluyveromyces marxianus, along with commercial probiotic yeast Saccharomyces boulardii, were characterised and tested for functional NAB production, whereas P. manshurica was used in NAB production for the first time. Growth and viability were assessed across a range of temperatures, pH, and iso-α-bitter acids. The tested yeasts withstood conditions typical of the beer matrix and human digestive tract and had a positive phenolic off-flavour phenotype. Two strains, K. lactis and K. marxianus, showed strong β-glucosidase activity, which may enhance beverage aroma complexity. Ethanol levels in beers fermented with non-Saccharomyces yeasts remained below the NAB limit (≤0.5% v/v). An analysis of volatile organic compound profiles revealed the potential of these yeasts to produce higher alcohols and esters valuable from a brewer’s perspective. This study provides valuable insight into novel probiotic fermentations and the potential application of unconventional yeasts in functional, aromatic, and health-oriented non-alcoholic beverages. Full article

A proper understanding of viticultural and oenological strategies is essential to adapt to climate change and consumer demands. The objective of this study was to evaluate the impact of different viticultural treatments and yeast strains on the chemical composition and sensory perception of wine. Two Verdejo musts, a control must (Must O) and one obtained with innovative viticultural strategies (Must E), were fermented with Saccharomyces cerevisiae, Lachancea thermotolerans, and a co-incubation of Lachancea thermotolerans with Metschnikowia pulcherrima. Fermentations with L. thermotolerans increased lactic acid content, reducing pH (a decrease of 0.2 points compared to controls) and having a positive impact on the perception of freshness. Wines fermented from Must E showed better colour parameters and a higher production of fermentative volatile compounds, but higher ethanol content and lower acidity. In contrast, wines fermented from Must O exhibited a more balanced aromatic profile, with fewer carbonyl compounds and higher alcohols (a 30% reduction in carbonyl compounds in wines fermented with non-Saccharomyces), which made them more harmonious in the sensory evaluations. The results highlight the importance of a good selection of viticultural and oenological strategies to achieve a desirable sensory profile under changing climatic conditions, highlighting the positive impact of non-Saccharomyces yeasts in improving acidity and aromatic profile. Full article

In response to the growing interest in less conventional alcoholic beverages, this study aimed to identify novel yeast strains suitable for sake production, with a focus on their potential application in bioflavouring. Commercially available strains of bottom-fermenting brewing yeasts (Saccharomyces pastorianus), a cryotolerant wine yeast (Saccharomyces bayanus), and a wild wine yeast (Torulaspora delbrueckii) were evaluated. The quality characteristics of sake obtained using non-conventional yeasts were compared with sake produced using Saccharomyces cerevisiae K7, one of the most commonly used strains in sake brewing. Sake made with non-conventional yeasts exhibited differences in fermentation kinetics, chemical composition, and sensory properties. Wine yeasts produced sake with the most favorable ester profile, markedly distinct from those obtained with other yeast strains used in the study. Compared to the conventional strain, the concentrations of the key contributors to the fruity/floral aroma, namely 3-methylbutyl acetate and ethyl hexanoate, in sake produced with S. bayanus were higher by 249.5% and 199.3%, respectively. The wine yeast S. bayanus may be considered the most promising strain for sake production due to its ability to generate elevated levels of volatile aroma compounds associated with Ginjo-ka characteristics, as well as its effectiveness in supporting a consistent and efficient alcoholic fermentation process. Full article

Sichuan Paocai is a representative traditional fermented vegetable in China, which is deeply embedded in local geographical and cultural heritage. However, regional differences in product characteristics remain poorly understood. In this study, the physicochemical properties, volatile compounds, and microbial communities of Paocai from seven production regions in Sichuan (named FB, AB, BZ, CD, DZ, MY, and YS) were systematically investigated. Parameters including pH, salinity, nitrite, organic acids, and color were determined, while volatile profiles were analyzed using an electronic nose and comprehensive two-dimensional gas chromatography–mass spectrometry. A total of 294 volatile compounds were identified, with alcohols, esters, and isothiocyanates emerging as the major contributors to flavor differentiation. UMAP and OPLS-DA analyses revealed distinct regional clustering, which was consistent with electronic nose profiling, and 111 volatile compounds were identified as key aroma markers. Microbial diversity was assessed using 16S rRNA gene sequencing, demonstrating that Lactobacillus, Lentilactobacillus, Pediococcus, and Weissella were the dominant taxa, although the richness varied significantly across regions. An LEfSe analysis further identified region-specific biomarkers, including Pediococcus, Lactococcus, and Leuconostoc in FB; Lactobacillus in AB; Pediococcus ethanolidurans in BZ; Levilactobacillus in DZ; Lentilactobacillus in MY; and a more diverse microbiota in MS. A correlation analysis highlighted the pivotal roles of distinct microbial groups in shaping and transforming flavor compounds across different regions. Overall, these findings provide scientific guidance for the development of high-quality, region-specific products and contribute to the protection, branding, and market competitiveness of geographically indicated foods. Full article

The substrates of kombucha typically consist of tea and sugar. In this study, the effect of initial sugar concentration on volatile compound and sensory characteristics of raw Pu-erh tea (RAPT) kombucha was investigated. Compared to tea free (S1) and sugar free (S2) samples, the sugared tea (39 g/L sucrose in S3 and 78 g/L sucrose in S4) revealed better sensory quality and higher liking scores after the fermentation process. Hence, high-throughput sequencing analysis was performed to determine the variation in microbial composition between S3 and S4. The result showed that S4 exhibited higher abundances of Komagataeibacter and Brettanomyces as compared to S3. In addition, S4 presented the most favorable sensory qualities characterized by higher intensities of fruity, alcoholic, and fatty aromas, and the highest overall liking score. The metagenomic and metabolomic analysis was employed to further explore the metabolic pathways of RAPT kombucha under the optimal sugar concentration. The metagenomic and metabolomic analyses revealed that the pathways related to carbohydrate and amino acid metabolism were highly active under optimal sugar content, with compounds including glucose 6-phosphate, pyruvate and glutamate suggested to be important metabolites in regulating the sensory quality of the kombucha beverage. This paper provides a scientific basis for optimizing sugar addition in kombucha production. Full article

This study investigated the potential of yeast polysaccharides (YPs) as an SO₂ substitute by adding varying concentrations (0–250 mg/L) prior to wine fermentation. The antioxidant activity and color stability were evaluated using UV–visible spectrophotometry, high-performance liquid chromatography, and colorimetric methods. Furthermore, HS-SPME-GC-MS and quantitative descriptive analysis were employed to compare the volatile compound profiles and sensory attributes between the optimal yeast polysaccharide treatment group (TS100, 100 mg/L) and the sulfur dioxide treatment group (S). Results showed that YPs addition effectively preserved phenolic compounds, with TS100 exhibiting the highest total phenols, flavonoids, and anthocyanins, where total anthocyanins reached 340.79 mg/L, a 2.52% increase over the S group. ABTS⁺ scavenging activity showed no significant difference from the S group, confirming strong antioxidant capacity. Flavor compound content was higher in TS100 (10,458.99 μg/L) than in the S group (10,156.07 μg/L), with ethyl caprylate and ethyl decanoate being particularly prominent. These esters contributed intense fatty and fruity aromas, enhancing the overall sensory quality of the wine. In summary, 100 mg/L YPs addition yielded the best wine quality, demonstrating promising potential as an SO₂ alternative in winemaking. Full article

This study investigated the correlation between flavor compounds and basic physicochemical properties of ordinary wine and Musalais wine with different pretreatment processes derived from Cabernet Sauvignon grapes. Key findings revealed significant differences in volatile compositions between Cabernet Sauvignon Musalais and the control group (ordinary wine, conventional Cabernet Sauvignon wine). Musalais samples exhibited certain commonalities in volatile profiles across different fermentation temperatures, and significant distinctions were also observed. Gas chromatography–ion mobility spectrometry (GC-IMS) identified 32 volatile compounds, with esters being the predominant contributors. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) based on the peak volumes of the 32 variables demonstrated that the first two principal components accounted for 72.2% of the cumulative variance, enabling effective differentiation of wine samples from the ordinary wine and Musalais of different treatment groups. PLS-DA further screened 13 characteristic biomarkers from the 32 volatile compounds through variable importance in projection (VIP) scoring. A correlation analysis was conducted on the basic indicators and volatile components of ordinary wine and three Musalais wines under different treatments, revealing differences both among the basic indicators (such as residual sugar, total phenolics, total acidity, total flavonoids, pH, and ethanol content) and between these indicators and volatile components. This methodology provides novel insights into crafting Cabernet Sauvignon Musalais with a unique flavor profile, advancing the optimization of fermentation strategies for traditional Chinese fruit wines. Full article