To enhance the solubility of rice bran protein (RBP) and thereby improve its application performance in food processing, the pH-driven method was employed in this study, under which RBP was treated at pH conditions of 1.5, 2.5, 3.5, 10, 11, and 12, and structural and functional properties before and after modification were compared and analyzed. The results showed that the solubility of RBP was observed to be gradually increased with rising pH, with the optimal effect achieved at pH12, where a solubility of 70.57% was reached, representing a significant improvement of 63.85% compared to the untreated group (6.72%). The average particle size, absolute ζ-potential value, and surface hydrophobicity of RBP were found to be significantly altered as the pH increased; After treatment at pH12, the average particle size was reduced to the minimum (140.47 nm), the absolute ζ-potential value was increased to the maximum (14.8 mV), and the surface hydrophobicity was elevated to the highest value (2289), along with a marked enhancement in intrinsic fluorescence intensity and a red shift in the maximum emission wavelength. Following pH12 treatment, the relative content of β-sheets in RBP was increased by 10.43%, while the relative contents of α-helices and β-turns were reduced by 3.29% and 9.13%, respectively. These findings indicate that pH-driven method can induce depolymerization of RBP molecules and strengthen intermolecular electrostatic repulsion, thereby significantly improving its solubility. This study offers a new approach to promote the widespread application of RBP.

In this study, different concentrations of Linseed gum (LG) and Methylcellulose (MC) were mixed, and the effects of LG concentration on the properties of composite polysaccharide water foam were systematically analyzed. The microstructure, pore structure, thermal stability and mechanical properties of composite polysaccharide aerogel (MC-LG) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The results showed that the viscosity of complex polysaccharide solution increased significantly with the increase of LG concentration (0.1wt%~0.5wt%), while the foam expansion rate first decreased and then increased, and reached the maximum value (7.59%) at 0.4wt%. Compared with pure MC water foam (76.40 μm), the bubble distribution of MC-0.4wt% LG water foam was more uniform, and the average size was reduced to 59.11 μm, and it still maintained good stability after 48 h storage. Scanning electron microscope and infrared spectrum analysis showed that hydrogen bond interaction was formed between MC and LG molecules, and MC-LG aerogel containing 0.4wt% LG presented a relatively uniform honeycomb porous structure. The results of mechanical properties showed that the Young's modulus of MC-0.4wt% LG aerogel reached 0.0982 MPa, which was significantly higher than that of single MC aerogel (0.0288 MPa), and the yield strength and compressive strength were also significantly improved. To sum up, when the concentration of LG was 0.4wt%, MC-LG aerogel had uniform and compact pore structure, good thermal stability and excellent mechanical properties, and the overall performance was ideal. This study can provide technical reference for the application of high-performance polysaccharide-based aerogels in food and biomedicine.

To investigate the effects of different processing methods on the structure and physicochemical properties of highland barley starch, this study used highland barley as the raw material to analyze the effects of four processing methods, namely, stir-frying (at 260 ℃ for 15 s), steaming (steaming in boiling water for 65 min), normal-pressure boiling (boiling in boiling water for 55 min), and high-pressure boiling (boiling in boiling water for 38 min), on the structure, physicochemical properties, and in vitro digestibility of highland barley starch. The results suggested that the raw starch particles were smooth and plump; The stir-fried starch was severely shrunk and aggregated; The steamed starch slightly expanded and wrinkled; The atmospheric boiled starch expanded, ruptured, and adhered together; The pressure boiled starch completely disintegrated. The boiling process severely damaged the structure and crystal structure of highland barley starch particles, with the relative crystallinity of the boiled starch being 5.61% (atmospheric boiling) and 4.77% (pressure boiling). Moreover, different processing methods led to changes in the gelatinization and thermal properties of highland barley flour. Typically, the gelatinization viscosity of highland barley starch under atmospheric boiling was only 26.67 cP, while that of stir-fried starch changed slightly, being 343 cP. Additionally, all the processing methods inhibited the retrogradation of starch, and the strongest anti-aging effect was achieved under atmospheric boiling, with a retrogradation value of 17 cP. As revealed by the analysis of sedimentation characteristics, the aging degree followed the tendency of atmospheric boiled starch>stir-fried starch>normal-pressure steamed starch>pressure boiled starch>raw starch. According to thermal property analysis results, the enthalpy value of pressure boiled starch exhibited the greatest change from 993.63 J/g (raw starch) to 759.89 J/g (pressure boiled starch), further confirming that pressure boiling had the most significant damage to the starch structure. In terms of rheological properties, all the starch pastes showed a shear-thinning fluid dominated by elasticity (G'>G'', tanδ<1). The values of G' and G'' increased with the increase in angular frequency, and the G' value of stir-fried starch demonstrated the most obvious increase. The tanδ value of pressure boiled starch showed irregular fluctuations, indicating the most thorough structural damage. By contrast, the tanδ values of starch under other processing methods fluctuated more gently, almost consistent with the raw starch state, suggesting the insignificant damage to their crystal structures. All treatments significantly increased the content of resistant starch (RS) (P<0.05), while atmospheric boiling and pressure boiling had the best enhancement effects, increasing from 63.55% to 69.10% (atmospheric pressure boiled starch) and 68.35% (pressure boiled starch), respectively. Therefore, they may be the processing methods for developing highland barley as a staple food. Stir-frying increased the RS content, but caused the soaring of the rapidly digestible starch (RDS) content to 31.79% and the slowly digestible starch (SDS) content of only 0.72%, which may cause a sudden increase in blood sugar. Boiling could reduce the RDS content and retain a part of SDS, helping to maintain the relatively stable blood sugar level. This study provides a solid theoretical basis and scientific guidance for the development and utilization of hulless barley resources. It holds positive significance in enriching the processing methods of hulless barley and is expected to promote its broader application in the food industry.

This study explored how repeated freeze-thaw cycles affect the quality of Duolang mutton, using the Longissimus dorsi muscle. After six cycles, measurements were taken for eating quality, safety parameters, texture properties, and indicators related to protein oxidation. Results showed a clear trend of quality degradation in the mutton as freeze-thaw cycles increased (P<0.05). Regarding eating quality, pH first rose and then fell. Water activity and water-holding capacity dropped significantly, while shear force decreased from 35.52 N to 19.98 N. Color stability worsened markedly, with the relative contents of deoxymyoglobin and metmyoglobin increased by 17.81% and 10.17%, respectively, whereas oxymyoglobin declined from 45.98% to 20.11%. Lightness (L^*) value first decreased, showed a partial recovery mid-process, and then fell again. Redness (a^*) and yellowness (b^*) values initially increased before decreasing. For texture, hardness and adhesiveness rose significantly, whereas gumminess and cohesiveness decreased notably. Springiness showed a gradual declining trend (P>0.05). In terms of safety and oxidation characteristics, the thiobarbituric acid reactive substances (TBARS) value increased from 1.42 mg/kg to 2.35 mg/kg, indicating advancing lipid oxidation. Total volatile basic nitrogen (TVB-N) first increased and then decreased. Total sulfhydryl content fell from 18.59 μmol/g pro to 10.33 μmol/g pro, while carbonyl content rose from 4.61 μmol/g pro to 7.23 μmol/g pro. Disulfide bond content first decreased and later increased, collectively pointing to intensified protein oxidation. In summary, repeated freeze-thaw cycles significantly exacerbated the quality deterioration of Duolang mutton by intensifying protein and lipid oxidation and disrupting muscle structure, and the degree of deterioration gradually worsened with increasing number of freeze-thaw cycles.

The preparation of active packaging materials from chitosan (CS), cellulose nanocrystals (CN), and epigallocatechin gallate (EGCG) involved a complex multi-component system that was highly susceptible to phase separation or aggregation of active components. This necessitated the urgent development of multi-component compatibility matching models and novel interfacial regulation strategies to stabilize the system and ensure homogeneous distribution of functional constituents. This study employed a pre-constructed EGCG-loaded CS/CN nanocrystal hydrogel (EGCG hydrogel) as the model system. The morphological and structural characteristics of the layer were systematically characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). Subsequently, molecular dynamics (MD) simulations were conducted with parameterized force fields to analyze the conformational dynamics and intramolecular/intermolecular interactions within the composite hydrogel system. The results demonstrated that the CS/CN nanocrystal hydrogel serves as an effective carrier for EGCG. With EGCG incorporation, the material surface exhibited increased roughness, thicker pore walls, and a more compact overall structure compared to the pristine hydrogel. Additionally, the EGCG hydrogel retained only a broad diffraction peak at 20.0° in XRD patterns, while the characteristic sharp peaks of pure EGCG disappeared, indicating the loss of crystalline EGCG domains within the matrix. Crucially, no new covalent bond-associated peaks emerged in the FT-IR spectra, confirming that EGCG was physically entrapped via non-covalent interactions rather than chemical bonding. MD simulations further revealed that increasing EGCG loading enhanced system stability, as evidenced by reduced fluctuations in root mean square deviation (RMSD) and solvent-accessible surface area (SASA). The radius of gyration stabilized at approximately 7 nm, suggesting a consolidated molecular conformation. Moreover, the number of hydrogen bonds between CN and CS increased significantly upon EGCG addition, implying that EGCG molecules reinforce interfacial interactions within the composite network through hydrogen-bond-mediated crosslinking. This study provides a theoretical foundation for the rational design and precise fabrication of controlled-release active packaging materials.

To address the limitations of traditional fermented dairy products in terms of flavor, nutrition and functional properties, this study introduces Limosilactobacillus fermentum FOSU YHD19 in synergy with a traditional starter culture. The effects of different inoculation concentrations (10⁵~10⁹ CFU/mL) on the quality of yogurt were systematically investigated. The fermentation process (including dynamic changes in pH, titratable acidity, water-holding capacity, and viable cell count) and storage stability were monitored, along with key indicators such as sensory properties, microstructure, and volatile flavor compounds after product maturation. The results demonstrated that the addition of FOSU YHD19 significantly enhanced fermentation performance, accelerating the acidification process (with the pH decreasing to 4.44 within 10 hours). It also effectively improved the texture characteristics of the yogurt by appropriately reducing hardness and elasticity, resulting in a denser and smoother mouthfeel. When the inoculation amount was 10⁷ CFU/mL, the fermented dairy product exhibited the best overall quality, outperforming the traditional starter culture. Specifically, its water holding capacity reached 94.1%±0.02%, with titratable acidity of 41.2±1.0 °T. Microstructural observation revealed a denser and more uniform protein gel network. Meanwhile, its overall sensory score (106.3±4.83) was higher than that of all other treatment groups. GC-MS analysis revealed an increase in the relative content of acids, alcohols, and ketones, imparting a richer fruity and cheesy aroma to the product. Furthermore, after 28 days of storage at 4 ℃, the viable bacterial count remained above 10⁶ CFU/mL, and all quality parameters remained stable. This study could provides both theoretical foundations and technical parameters for developing premium yogurt products with enhanced organoleptic properties and probiotic benefits.

To address the limitations of single-strain fermentation of tea, specifically its single metabolic pathway and limited flavor enhancement, this study employed co-liquid-state fermentation of crude dark tea using Aspergillus cristatus G-Y and Bacillus subtilis SO-2, with unfermented tea broth as the control (CK group). The synergistic effects of the dual strains on the regulatory mechanisms of soluble sugars, tea pigments, phenolic compounds, antioxidant activity, and flavor substances in tea broth were systematically investigated. The results demonstrated that co-fermentation significantly reduced polysaccharide content (0.61 mg/mL, P<0.05) and promoted the accumulation of theabrownins (positively correlated with Δa value). In terms of polyphenol metabolism, single-strain fermentation with B. subtilis reduced the levels of total polyphenols and total flavonoids (by 11.96% and 18.71%, respectively), and single-strain fermentation with A. cristatus primarily drove the degradation of esterified catechins. Importantly, co-fermentation retained the degradation advantage of A. cristatus single fermentation on esterified catechins (reduction>90%), and further regulated the polyphenol transformation pathway through microbial synergy, promoting the accumulation of gallic acid, free catechins, and other compounds, and significantly enhancing antioxidant activity (DPPH· scavenging activity IC₅₀=0.0315 mg/mL, ABTS⁺· scavenging activity IC₅₀=0.0720 mg/mL, P<0.05). Flavor analysis revealed that the dual-strain interaction coordinated amino acid metabolism, leading to a balanced accumulation of sweetness-associated amino acids (141.59 mg/L) and bitterness-associated amino acids (129.01 mg/L). Moreover, through a coupled pathway of "glucosinolate hydrolysis (A. cristatus)-esterification (B. subtilis)," key aroma compounds such as benzyl isothiocyanate were substantially enhanced (ROAV=50.77, up to 49-fold higher than in single-strain fermentations). The total volatile metabolites increased by 6.18% compared to the control. Sensory evaluation confirmed that the co-fermentation group achieved the highest scores in aroma and taste, highlighting the synergistic effect of the dual strains on flavor balance. This study demonstrates that co-fermentation with A. cristatus and B. subtilis effectively modulates the transformation of bioactive compounds and the synthesis of key flavor substances through complementary metabolic pathways, significantly improving the overall quality of tea broth.

To increase the content of 4-vinylguaiacol (4-VG), a health-promoting flavor compound in Baijiu, microbial strains with high-yielding 4-VG were isolated and its production was optimized for application in Baijiu fermentation. In this study, high-yielding 4-VG strains were screened from Shennongjia sauce-flavor Daqu through primary and secondary screening, followed by identification. The fermentation conditions for 4-VG production by the strain were optimized using single-factor and response surface methodology (RSM) methods, and the strain tolerance was further investigated. Ultimately, the selected strain was used for fermentation in Baijiu. The results showed that the strain of JP-2 exhibiting both high endogenous 4-VG production and efficient precursor conversion was obtained by screening and was identified as Cronobacter maloniacus. The optimal fermentation conditions for high-yielding 4-VG of C. maloniacus JP-2 were sorghum juice-based medium, a sucrose concentration of 26.90 g/L, an initial pH of 5.0, and a fermentation time of 72 hours. Under the optimized conditions, the content of 4-VG reached 4342.92±401.62 μg/L, representing a 190.45% increase compared to the pre-optimization level. The tolerance test indicated that C. maloniacus JP-2 could survive at the condition of 6% alcohol, pH4.0, 45 ℃, and 300 g/L glucose, respectively. Compared to the control group, 4-VG contents in fermented grains at the end of fermentation and Baijiu made with biofortification with C. maloniacus JP-2 increased by 53.85% and 279.80% (P<0.05), respectively. Additionally, the JP-2 inoculation also increased esters contents and improved sensory qualities, particularly enhancing caramel and floral-fruity notes in Baijiu. This study would provide excellent strains and a data basis for improving the quality and health benefits of sauce-flavor Baijiu.

Crude polysaccharides from Flos. Dolichos lablab L. exhibit various biological activities, including antioxidant, hypoglycemic, and hypolipidemic effects. However, in practical applications, extreme conditions such as high-temperature infusion, gastric acid environments, and sterilization processes may compromise the stability of their biological activities. To investigate the effect of fermentation on the stability of biological activity of crude polysaccharides from Flos. Dolichos lablab L. under extreme conditions, the structural and activity changes of the polysaccharides before and after fermentation were measured using heat, acid, and sterilization treatments to evaluate the impact of fermentation on the stability of their biological activity. The results indicated that, in terms of structural characteristics, the molecular weight of crude polysaccharides from Flos. Dolichos lablab L. decreased both before and after fermentation, as well as after treatments at 100 ℃ for 3.5 h, pH=1, and 121 ℃ for 30 min. Furthermore, the molecular weight after fermentation was significantly lower than that before fermentation under all treatment conditions. In terms of biological activity, after heat, acid, and sterilization treatments, fermentation enhanced the scavenging rate of crude polysaccharides from Flos. Dolichos lablab L. against the 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) diammonium salt cation (ABTS⁺) radical, demonstrating excellent antioxidant stability. After heat and acid treatments, fermentation increased the α-amylase inhibition rate. However, under sterilization conditions of 121 ℃ for 20 min, fermentation did not enhance inhibition rate, whereas it improved it under all other conditions. After heat, acid, and sterilization treatments, under most conditions, the binding capacity of fermented crude polysaccharides from Flos. Dolichos lablab L. to sodium glycodeoxycholate and sodium taurodeoxycholate decreased compared to the samples before fermentation. In summary, the fermentation process enhanced the antioxidant capacity and hypoglycemic effects of crude polysaccharides from Flos. Dolichos lablab L., while improving their stability. Although no significant improvement in hypolipidemic activity was observed, the fermentation process still ensured the consistent performance of the polysaccharide in this regard. This study provides a theoretical basis for the stability of the primary biological activities of crude polysaccharides from Flos. Dolichos lablab L. during fermentation, offering practical guidance for their application in the functional food industry.

Objective: This study aimed to explore high-efficiency aroma-producing functional strains from the stacked fermented grains of Jiangxiang Baijiu, systematically analyze their biological characteristics, environmental tolerance, and brewing functions, and further provide scientific data support for the development of Baijiu microbial strain resources and the optimization of flavor quality. Methods: Strains were isolated from the stacked fermented grains of Jiangxiang Baijiu. Strain identification was completed through morphological observation, physiological and biochemical experiments combined with whole-genome sequencing. Gradient stress experiments were used to analyze the strain's tolerance ability. Gas chromatography technology was applied to detect the content of flavor substances of the strain in sorghum juice medium and simulated fermented grain fermentation system, respectively. Finally, Illumina NovaSeq sequencing technology was used for whole-genome sequencing, and functional annotation was conducted to analyze core functional genes. Results: A high-efficiency aroma-producing strain XJ-YDG001-1 was isolated and identified as Geotrichum candidum. This strain could produce floral, fruity, sweet, and acidic aromas, and tolerate 6% ethanol and 8% lactic acid. In the sorghum juice medium fermentation system, strain XJ-YDG001-1 significantly increased the accumulation of ester substances, raising the ester content from the initial (5120.41±58.43) mg/L to (38186.97±158.89) mg/L. Further verification through simulated fermented grain experiments showed that this strain could also effectively promote ester synthesis, increasing the ester content in fermented grains from (60.41±3.86) mg/100 g to (188.65±15.54) mg/100 g. Whole-genome sequencing revealed that the strain had a genome length of 22937131 bp, a GC content of 46.09%, and 6955 predicted protein-coding genes. The results of genomic functional annotation indicated that the strain's genes were highly enriched in metabolism, genetic information processing, and molecular catalytic functions. It also carried key genes such as glycoside hydrolase (GH15) and esterase (CE10), which could participate in the flavor synthesis process of Jiangxiang Baijiu by decomposing substrates and catalyzing precursor substances. Conclusion: Geotrichum candidum XJ-YDG001-1 has excellent aroma-producing ability and environmental tolerance, and has potential application value in the flavor regulation of Jiangxiang Baijiu. This study provides a theoretical basis for the exploration and utilization of functional microorganisms in Baijiu production.