Objectives: To obtain a stable Rhodotorula mucilaginosa with excellent aroma production for enhancing the flavor quality of Huangjiu fermentation. Methods: The optimal fermentation strains were selected from nine isolates by analyzing tolerance， β-glucosidase activity and aroma production characteristics， and co-fermented with Saccharomyces cerevisiae to investigate the effect of co-fermentation on the flavor quality of Huangjiu. This study further used headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) in combination with sensory evaluation and physicochemical indexes to investigate the effect of co-fermentation on the flavor quality of Huangjiu. Results: Nine strains of R. mucilaginosa were identified and screened. All strains grew well under the conditions of 10-35 ℃ and pH 5.0-6.5， with good low temperature and acid tolerance and high β-glucosidase enzyme activity (253.7-492.2 U/mL)， and the ethanol tolerance of different strains varied greatly. The content of alcohol， aldehyde， acid and ester in the fermentation broth of JH-6 strain was significantly higher than that of other strains， and it had good aroma-producing performance. The co-fermentation of R. mucilaginosa JH-6 and S. cerevisiae with Huangjiu conformed to the national standard GB/T 13662—2018 of Huangjiu， and compared with the Huangjiu produced without inoculation of JH-6， the alcoholic strength was lowered， the content of ester was increased， the texture was soft and harmonious， the aroma of flowers and fruits was prominent， and the flavor quality was obviously improved. The flavor quality of the wine was significantly improved with the prominent aroma. Conclusion: In this study， R. mucilaginosa was systematically screened and evaluated， and a strain JH-6 with good tolerance and optimal aroma production characteristics was obtained， and the flavor quality of Huangjiu was improved by co-fermentation of this bacterium with S. cerevisiae， and the study provides technological support for the application of R. mucilaginosa in the fermentation of Huangjiu.

Objectives: The effects of clay jars and stainless steel jars on the flavor substances and quality of dry red wine during fermentation in the eastern foot of Helan Mountain in Ningxia were investigated. Methods: The Cabernet Sauvignon grape was used as the experimental material， and the alcohol fermentation was carried out in clay jar and stainless steel jar. The content of 9 kinds of organic acids in wine before and after alcohol fermentation was analyzed by liquid chromatography. The distribution of volatile aroma substances in wine before fermentation and at the end of alcoholic fermentation was analyzed by electronic nose combined with headspace solid phase microextraction gas chromatography-mass spectrometry. Results: The total amount of organic acids showed a downward trend during the fermentation process， and the concentration of compounds with floral， fruity and sweet aromas increased significantly (P<0.05)， and the concentration of compounds contributing to grassy and green aromas decreased to varying degrees. Compared with stainless steel jar fermentation， the total amount of organic acids in ceramic jar fermentation wine was higher (92 425.90 ng/mL)， and the corresponding sensor response values of short-chain alkanes such as alcohol ether aldehyde ketones， methane and inorganic sulfur compounds were higher. Dodecanedioic acid， 4-acetylbenzoic acid， 5-oxotetrahydrofuran-2-carboxylic acid， glycerol distearic acid ester， δ-tetradecalactone， diethyl succinate in clay jar fermented wine， and phenylethyl acetate， benzyl alcohol， 1-hexanol in stainless steel jar fermented wine are the characteristic flavor substances that distinguish the two fermentation jars. The results of sensory evaluation showed that the taste of pot-fermented wine was more complex and layered， and its aroma intensity was also more advantageous. The mellowness of stainless steel jar fermented wine was better. Conclusions: Clay jar fermentation can enhance the floral and fruity， sweet volatile flavor of Cabernet Sauvignon wine， and increase the complexity and layering of the taste. The wine fermented in stainless steel cans has honey aroma and roast aroma， and the mellow taste is better.

Objective: To investigate the mechanism of synergistic inhibition of α-amylase (AMY) by three flavonoids [baicalein (Bai)， genistein (Gen)， isoliquiritigenin (Isl)] combined with acarbose (Aca). Through methods such as inhibition rate experiments， combination index (CI) analysis， fluorescence spectroscopy， ultraviolet spectroscopy， infrared spectroscopy， and molecular dynamics simulation， the inhibitory effects and action mechanisms of the combined inhibition on AMY were systematically studied. The results show that the inhibitory effects of Bai/Gen/Isl combined with Aca on AMY were significantly enhanced at molar ratios of 2∶1， 3∶1， and 4∶1. Among them， Bai-Aca and Isl-Aca exhibited a strong synergistic effect at a molar ratio of 3∶1(CI < 1)， while Gen-Aca showed synergism only at a molar ratio of 3∶1 and under the specific condition of 0.3 < Fa < 0.9(fraction affected). Fluorescence spectroscopy analysis showed that the combined inhibitors bind to AMY via a static quenching mechanism. Among them， Isl-Aca exhibits the highest binding constant (Ka) with AMY [K = (4.826±0.206)×105 L/mol at 298 K； Ka = (35.172±0.255)×105 L/mol at 300 K]， and its affinity is significantly enhanced with increasing temperature (P < 0.05)， indicating that the complex formed by Isl-Aca and AMY has the optimal stability. Thermodynamic parameters indicated that hydrophobic interactions were the main driving force for Bai-Aca and Isl-Aca， while Gen-Aca relied on hydrogen-bond binding. Synchronous fluorescence and ultraviolet spectroscopy showed that the combined inhibitors regulated the activity of AMY by changing the microenvironment of tryptophan (Trp) and tyrosine (Tyr) residues， with the inhibitory effect of Trp residues being dominant. Infrared spectroscopy and molecular dynamics simulation further revealed that Bai-Aca and Isl-Aca promoted the transformation of the secondary structure of AMY into a more stable β-turn， while Gen-Aca induced the formation of α-helix. However， the free-energy landscape of the latter complex presented a dispersed energy cluster， indicating weaker stability. In conclusion， the Bai-Aca and Isl-Aca combined inhibition systems significantly reduce the dosage of inhibitors through multi-target synergistic effects， while maintaining the high stability of the AMY complex. This provides a theoretical basis for the development of novel diabetes treatment strategies and functional foods based on flavonoids.

Objective: A high-fat diet is a risk factor for cognitive impairment， but its underlying biological mechanisms have not been elucidated. Methods: twenty-four male 3-month-old C57BL/6J mice were randomly divided into two groups， and fed with normal chow diet (ND) and high-fat diet (HFD) for 12 weeks. At the end of the experiment， the glucose tolerance test (GTT) was performed. Cognitive function was evaluated with the Morris Water Maze (MWM) test. After overnight fast， the mice were sacrificed and serum and colon contents were collected. Serum insulin levels were detected by ELISA， serum glucose levels were determined by colorimetric method and HOMA-IR was calculated. Liquid chromatography tandem mass spectrometry was used to detect serum BCAA levels. 16S rDNA amplicon sequencing was used to detect gut microbiota alterations， and their correlation with serum BCAAs was performed by Spearman correlation. Results: After 12 weeks feeding， compared with the control mice， the HFD-fed mice showed significant increases in body weight (31.6 g vs 37.5 g， P<0.001)， body fat rate (3.2% vs 5.8%， P<0.001)， area under curve (AUC) of GTT (1 440 mmol/L·min vs 1 841 mmol/L·min， P<0.05)， and fasting serum levels of isoleucine (1.27-fold of the control group， P<0.05) and total BCAAs (1.16-fold of the control group， P<0.05). Additionally， the fluorescence intensity of NeuN-positive immunoreactive regions in the dentate gyrus of the hippocampus was significantly decreased in the HFD group (27 vs 12， P<0.01). HFD-fed mice displayed a decrease in the number of platform and the target quadrant entries during the probe trial compared with the control group， and these indicators were negatively correlated with serum isoleucine and total BCAA levels. In addition， the composition of gut microbiota in HFD group was significantly different from that in the control group. At the genus level， Romboutsia and Blautia are the dominant microbiota in the colon of HFD-fed mice. Bacterial functionality prediction indicated that gut microbiota genes involved in BCAA degradation were significantly reduced in HFD group compared with the control group. The Parvibacter genus is negatively correlated with isoleucine levels (P=0.01)， while the Blautia and Anaerotruncuus genus are positively correlated with isoleucine levels (the P-value were 0.00 and 0.03， respectively). Conclusion: Gut microbiota may be the link between elevated serum BCAA levels and HFD-induced cognitive impairment.

Objectives: Curcumin has good biological activity， but its application in food is limited because of its poor solubility， stability and bioaccessibility. Methods: Curcumin loaded Pickering emulsion was prepared by using whey protein isolate (WPI) and soy protein isolate (SPI) as solid particles. The rheological properties， microstructure and secondary structure of the emulsions were characterized and simulated digestion in vitro. Results: The Pickering emulsion stabilized by WPI / SPI had a good embedding rate of curcumin， with a maximum of 74.33%， and had good storage stability. The rheological properties show that the Pickering emulsion exhibits good gel properties under low shear force. The microstructure showed that the curcumin-loaded Pickering emulsion was oil-in-water type. The Fourier results showed that the relative content of protein secondary structure in Pickering emulsion was changed by hydrogen bonding after embedding curcumin. In vitro digestion results showed that WPI/SPI stabilized Pickering emulsion significantly improved the bioaccessibility (from 12.60% to 34.31%) and antioxidant activity of curcumin， and the release of curcumin in vitro conformed to the zero-order kinetic model. Conclusions: The Pickering emulsion stabilized by composite protein particles has good stability and can be used as a delivery carrier of curcumin to improve its bioaccessibility and further provide a reference basis for the stabilization， development and application of curcumin and other bioactive components.

This study aimed to investigate the effects of different extraction temperatures on the chemical composition and flavor characteristics of coffee brews， in order to optimize atmospheric-pressure extraction and improve coffee flavor quality. Extraction temperatures (55-95 ℃) were adjusted to analyze the volatile and non-volatile compounds and sensory characteristics of coffees with different roast degrees (light， medium， and dark)， and to examine how temperature influences their chemical composition and flavor formation. Gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) were used to quantitatively analyze chemical components in coffee brews， and descriptive sensory evaluation was conducted to systematically assess sensory attributes. The results showed that extraction temperature significantly affected both the release of volatile compounds and the dissolution of non-volatile components (P<0.05). High-temperature extraction (95 ℃ and 85 ℃) increased extraction yield (>22%) and bitterness/astringency， whereas acidity and caramel notes were more pronounced at lower temperatures. Combined sensory and quantitative analyses indicated that high-temperature extraction improved extraction efficiency but led to the loss of some aroma compounds， while low-temperature extraction preserved more key aroma components. Significant differences in chemical composition and sensory properties were observed among coffees of different roast degrees at different extraction temperatures； higher temperatures were more suitable for comprehensive extraction of dark-roasted coffee， whereas lower temperatures were advantageous for aroma retention in light and medium roasts. This study provides theoretical support for optimizing coffee extraction processes， and future work will integrate other variables (e.g.， pressure and extraction time) for multidimensional research to further elucidate the mechanisms and control strategies of coffee flavor formation.

To investigate the effects of drying methods on the structure characteristics and immunomodulatory activity of polysaccharides derived from Morchella esculenta， fresh M. esculenta were separately subjected to hot-air drying (HD) and freeze drying (FD). Polysaccharides from M. esculenta (MEP) extracted from the two dried samples were purified by macroporous adsorption resin column chromatography， yielding HD-treated MEP (HMEP) and FD-treated MEP (FMEP). The monosaccharides of HMEP and FMEP were consisted of mannose， glucose and galactose while with different molar ratios of 1∶0.34∶0.33 and 1∶4.50∶0.02， respectively. HD treatment caused the break of C—O—C glycosidic linkages in polysaccharides chains and enhanced the abundance of α-configuration in polysaccharides from M. esculenta. Both HMEP and FMEP improved immunity by inducing phagocytosis and the secretions of NO， TNF-α， IL-6 and IL-1β of RAW 264.7 cells. At 50 μg/mL， FMEP stimulated RAW 264.7 cells to secrete NO at a level of (35.29±1.25) μmol/L， which was higher than that induced by HMEP [(28.05±2.52) μmol/L] and the model group [(32.47±1.30) μmol/L] at 50 μg/mL. At 25 μg/mL， FMEP stimulated macrophage TNF-α secretion to (289.96±49.00) ng/mL， which was higher than that of HMEP [(188.56±13.60) ng/mL] and the model group [(97.76±2.00) ng/mL]. This indicates that FMEP exhibited higher immunomodulatory activity than HMEP. After comprehensive consideration， freeze drying would be recommended as a suitable drying process for use in the preparation of immunomodulatory polysaccharides from M. esculenta as functional foods.

Streptococcus thermophilus CCFM1095 in combination with Lactobacillus helveticus CCFM1263 significantly improves fermentation efficiency， but the mechanism of interaction has not been cleared. Therefore， this paper evaluates the fermentation characteristics of the complex strains and the metabolomic profiles of the fermented milks， and analyses the effects of key metabolites on fermentation characteristics. Metabolomics analyses showed that compounding significantly promoted the enrichment of pathways such as alanine， aspartate and glutamate metabolic pathways， lysine degradation pathway， TCA cycle， pyruvate metabolism and nicotinic acid and nicotinamide metabolic pathways， and increased the utilisation of citrate and nicotinamide by the strains Production of L-glutamate， fenugreek acid， α-ketoglutarate， and 4-trimethylaminobutyric acid lipids， which significantly promoted the growth of both strains. The fermentation characteristics of the complex fermented milk were significantly improved. The viable bacterial count of the strains could reach 108 CFU/mL. This study provides theoretical basis for further analysis of the interaction mechanism between Streptococcus thermophilus and Lactobacillus helveticus.

Objectives: This study aimed to optimize the extraction process of Zanthoxylum bungeanum seed oil to enhance the comprehensive utilization value of its by-products. Methods: The fatty acid composition of Zanthoxylum bungeanum seed oil was analyzed using gas chromatography-mass spectrometry. With the oil yield and the relative content of the main fatty acids as evaluation indices， the optimal extraction conditions were determined through single-factor experiments and orthogonal array design. Results: The main fatty acid in the oil was α-linolenic acid (relative content 23.39%). The optimal extraction conditions were as follows: Extraction temperature 60 ℃， extraction time 50 min， solid to liquid ratio 1∶3， ethanol volume fraction 90%， and extraction repeated three times. Under these conditions， the α-linolenic acid content reached 23.32%. Conclusions: This study clarifies the fatty acid profile of Zanthoxylum bungeanum seed oil and provides an important basis for its efficient extraction and for the resource utilization of Zanthoxylum bungeanum by-products.

ε-polylysine (ε-PL) is a common natural food preservative. In this paper， the antibacterial effect of ε-polylysine-sodium hexametaphosphate (ε-PL-SHMP) polymer on pasteurized milk and its effects on the physicochemical properties of milk system were analyzed. Combined with SDS-PAGE map， the stability analysis of protein changes in milk. The results showed that ε-PL-SHMP polymer had a good inhibitory effect on the number of Bacillus cereus in milk within 7 days and the number of Staphylococcus aureus in milk below 106 CFU/mL within 3 days compared with the blank group during the 1-week storage period. The pH value of pasteurized milk treated with ε-PL-SHMP polymer was maintained in the range of 6.8-6.9， which was not significantly changed from other groups， and the relative viscosity increased slightly from 0.0008 Pa·s to 0.0012 Pa·s on the 7th day compared with that of the ε-PL treatment group. SDS-PAGE spectra showed that ε-PL binded to and precipitated proteins in milk with the prolongation of storage time， while proteins in the ε-PL-SHMP polymer treatment group were more stable. The stability analysis showed that the stability of the ε-PL alone treatment group was the worst， and the pasteurized milk system with ε-PL-SHMP polymer showed a good and stable dispersion state. Conclusion: ε-PL-SHMP polymer can improve the application quality of ε-PL in milk system， have a better antibacterial effect on pasteurized milk and improve the stability of the milk system.