Yellow glutinous rice wine is a traditional Chinese beverage created by soaking, boiling, and fermenting glutinous rice. The majority of current studies on the flavor of yellow glutinous rice wine are based on instrumental analysis, with sensory analysis being overlooked. In this study, 36 volatile chemicals in the fermentation process of yellow wine were annotated by GC-MS and then an OPLS-DA model was built to screen out 13 distinctive substances (VIP > 1, p < 0.01). The relative odor activity value (ROAV) was calculated using the threshold values of these chemicals and 10 substances, including alcohols, esters, and aldehydes, were found as key contributors to the overall flavor of yellow wine. Following that, consumers quantified the sensory descriptors of yellow wine using rate-all-that-apply (RATA), and correspondence analysis revealed three groups of characteristic flavors and odors. Alcohols and esters were found to be key producers of flowery and fruity scents in yellow wine, according to correlation analysis. We discovered two alcohols that are rarely found in yellow wine: [R,R]-2,3-butanediol and 1-phenylethanol. The former was found to be favorably connected with wine scent and pungent odor, and its specific effect on flavor should be researched further.

The present study employed Hunan local Tuqu for fermentation and investigated the physicochemical properties, microbial community composition, and volatile flavor compounds of the fermented grains, as well as the correlation between the physicochemical indicators and the microbial community. The findings reveal that the activities of α-amylase and glucoamylase were highest during the initial stages of the fermentation process. The acid protease activity increased to 30.6 U/g on the second day and then decreased. Cellulose and lipase activities both showed an increasing trend. The moisture content increased sharply to 73.41% and then remained relatively stable. The acidity was highest on the eighth day. Fifty genera of bacteria and twenty-two genera of fungi were detected. Lactobacillus was dominant among bacteria, and Saccharomyces was dominant among fungi. A correlation analysis showed that there were positive correlations between moisture, acidity, cellulose, lipase activities and Lactobacillus, and there were positive correlations between moisture content, acidity, cellulase activity, acidic protease activity and Saccharomyces. A total of 46 volatile flavor compounds were detected, of which 6 alcohols and 14 esters constituted the major portion, and 9 key flavor compounds with an ROAV > 1 were identified throughout the fermentation process. Isoamyl acetate had the highest ROAV and made the greatest contribution to the flavor.

Vitis davidii Foex whole seed (VWS) is a by-product during the processing of grape products, which is rich in bioactive compounds that have great potential in the food industry. In this study, the bioactive compounds and antioxidant activity of VWS were determined, and their dynamic changes during in vitro colonic fermentation were also investigated after VWS subjected to in vitro simulated digestion. Results showed that VWS were rich in polyphenols (23.67 ± 0.52 mg GAE/g), flavonoids (13.13 ± 1.22 mg RE/g), and proanthocyanidins (8.36 ± 0.14 mg CE/g). It also had good DPPH and ABTS radical scavenging activity, which reached 82.10% and 76.10% at 1000 μg/mL. The alteration trend of the antioxidant activity during in vitro fermentation for 24 h was consistent with that of the content of bioactive substances, such as polyphenols, with the extension of fermentation time. The bioactive compounds and antioxidant activity showed a trend of increasing and then decreasing, reaching the highest value at 8 h. The high-throughput sequencing analysis of the regulatory effect of VWS on intestinal micro-organisms revealed that VWS influenced intestinal microbiota diversity. The relative abundance of beneficial microbiota, such as Blautia and Parabacteroides, increased by 4.1- and 1.65-fold after 24 h of fermentation compared with that of the control group. It also reduced Escherichia-Shigella by 11.23% and effectively reduced host inflammation, while increasing the contents of acetic acid, propionic acid, and other metabolites. Taken together, these results reveal the value of VWS utilization and provide new insights into the nutritional and microbiota modulation effects of VWS, which could therefore serve as a nutraceutical ingredient in health promotion.

Background: Glycolipid metabolism is essential for maintaining metabolic homeostasis. As a new postbiotic, pasteurized Akkermansia muciniphila (P-AKK) is important for the regulation of immunity and metabolism. Objectives: This study aimed to evaluate the effects of P-AKK on glycolipid metabolism in Caenorhabditis elegans fed a high glucose diet. Results: We discovered that feeding nematodes P-AKK improved their healthy lifespan when fed a high-glucose diet. Furthermore, P-AKK contributes to reducing the accumulation of glucose, advanced glycation end products, and lipids and maintains a better physiological state. In addition, P-AKK improved the composition of free fatty acids and decreased the total free fatty acid content of C. elegans. Transcriptome sequencing analysis revealed that P-AKK induced significant enrichment of carbohydrate, oxidative phosphorylation, and fatty acid metabolism pathways. These significantly enriched biological processes were closely related to glucose and lipid metabolism. Among them, P-AKK activated the β-oxidation of fatty acids while inhibiting the de novo synthesis of fatty acids to regulate fatty acid metabolism. Conclusions: The administration of P-AKK positively affected the body phenotypes of C. elegans under high glucose conditions. P-AKK mitigated the fat accumulation induced by a high-glucose diet by regulating key metabolic enzymes, including acyl-CoA synthetase and stearoyl-CoA desaturase.

Theaflavins, benzotropolone compounds formed during black tea processing via catechin condensation, have drawn attention for their potential health benefits and diverse biological effects. This study evaluated the inhibitory effects of four theaflavin monomers—theaflavin-3′-gallate, theaflavin-3,3′-digallate, theaflavin-3-gallate, and theaflavin—on eight CYP450 enzymes using pooled human liver microsomes and specific probe substrates, and seven UGT enzymes using human recombinant UGT enzymes and specific probe substrates. Theaflavin-3′-gallate moderately inhibited CYP1A2-catalyzed phenacetin metabolism and CYP2C8-mediated amodiaquine metabolism, with IC₅₀ values of 8.67 μM and 10–20 μM, respectively. Theaflavin-3,3′-digallate exhibited similar effects. Both compounds showed negligible inhibition with other CYP enzymes. In UGT assays, theaflavin-3′-gallate and theaflavin-3,3′-digallate moderately inhibited UGT1A1- and UGT1A3-mediated beta-estradiol glucuronidation (IC₅₀: 1.40–5.22 μM), with weak or no effects on other UGT enzymes. Molecular docking revealed that CYP1A2-theaflavin-3′-gallate and CYP2C8-theaflavin-3,3′-digallate interactions were non-competitive, primarily mediated by hydrogen bonding and π-interactions. UGT1A1-theaflavin interactions suggested non-competitive inhibition, while UGT1A3-theaflavin interactions indicated competitive inhibition. Other enzyme-theaflavin interactions exhibited minimal binding energy differences, implying mixed-type inhibition. These findings highlight the selective inhibitory effects of theaflavins on specific hepatic enzymes, with potential implications for nutrient interactions, particularly for nutrients metabolized by CYP1A2, CYP2C8, UGT1A1, and UGT1A3. Further research is needed to explore the in vivo relevance and assess the dietary implications of theaflavin-rich black tea in nutrition and metabolism.

Zhuyecha (ZYC, Camellia sp.) is a newly discovered special wild tea plant resource in Cangwu County, Wuzhou City, Guangxi Province, China. However, there have been few scientific studies on it. This study investigated its morphological and chemical characteristics. The results revealed that ZYC is an arbor-type, upright plant with lanceolate leaves. The flower has five petals, five sepals, a trifid style, and a glabrous ovary. ZYC exhibited a unique chemical profile distinguished from common tea cultivars. Compared with the control cultivated varieties (Hongyan 12, Fuyun 6, and Yinghong 9), ZYC fresh leaves contained significantly higher contents of theobromine, theophylline, and gallic acid, but considerably lower caffeine and lower total catechins. The principal catechins were epi-form/galloylated catechins EGCG and ECG. Notably, theobromine was the most abundant alkaloid in ZYC, followed by caffeine and theophylline. In ZYC fresh leaves, 15 differential non-volatile metabolites were identified, and 22 key aroma compounds were screened, including linalool, (E)-2-hexenal, hexanal, heptan-2-ol, and β-myrcene, among others. The volatile components were primarily alcohols, aldehydes, and esters, contributing to floral, fruity, and green aroma attributes. This work enhances the understanding of the botanical and phytochemical properties of ZYC and provides scientific guidance for further research and efficient utilization of this natural low-caffeine/high-theobromine tea resource.