In order to select the yeast strain suitable for Sanhua plum wine production, five commercial Saccharomyces cerevisiae strains (SY, D254, DV10, EC1118, and K1) were used for Sanhua plum wine fermentation in this study. A comprehensive evaluation of the effects of these yeast strains on Sanhua plum wine quality was conducted by analyzing basic physicochemical parameters, total phenolics and flavonoids, antioxidant activity, profiles of organic acids and amino acids, volatile compounds, and sensory characteristics. The results indicated that the wines fermented with the five yeast strains exhibited an alcohol content of 12.57%~12.97% (v/v), along with high dry extract content (40.00~43.90 g/L), and low methanol levels (30.86~37.41 mg/L). Among them, the D254-fermented Sanhua plum wine showed the lowest total acid content (8.29 g/L) and the lowest malic acid content (5.96 g/L). The DV10-fermented Sanhua plum wine exhibited the strongest antioxidant activity, as evidenced by its highest DPPH· scavenging capacity (911.26 mg V_C/L) and strongest reducing power (976.40 mg V_C/L). The Sanhua plum wine fermented with SY yeast demonstrated the highest amino acid content (402.33 mg/L), the most complex volatile composition, and the highest sensory evaluation score (89.90 points), indicating its superior suitability for Sanhua plum wine fermentation. This study provides a theoretical foundation for yeast selection in the production of Sanhua plum wine.

Hyperoside (HYP), a flavonoid with potent antioxidant, antitumor, and anti-inflammatory activities, has limited applications in pharmaceutical development and functional foods because of its poor water solubility and low bioavailability. In this study, hyperoside-loaded soybean hydrophobic peptide-based nanocomplexes (SPN-HYP) were prepared using a pH-driven method. The optimal HYP loading concentration was determined, and the physicochemical properties and bioaccessibility of the resulting nanocomplexes were systematically characterized. The results showed that soybean peptide hydrophobic aggregates could be used to construct HYP-loaded nanocomplexes, thereby improving the water solubility and stability of HYP. The nanoparticle dispersion was yellow in appearance, with an encapsulation efficiency above 90%, a loading capacity of 18.88%±0.033%, and a particle size ranging from 160 to 180 nm. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Zeta potential analysis confirmed the successful incorporation of HYP into SPN. After storage at 4 ℃ for 15 days, the particle size variation remained below 10%. In vitro simulated gastrointestinal digestion showed that the bioaccessibility of HYP in the SPN-HYP system was significantly higher than that of free HYP (P<0.05). In addition, the SPN-HYP system effectively preserved the antioxidant activity of HYP and improved its stability and bioaccessibility during gastrointestinal digestion. Therefore, the soybean hydrophobic peptide-based nano-delivery system shows promising potential for enhancing the application of hyperoside in functional foods and pharmaceutical development.

To elucidate the relationship between the structure of wax-based oleogels and bread quality, this study examined the effects of varying cooling temperatures (20, 4, −18 ℃) on the crystalline network structure of rice bran wax (C24-C32)—high oleic sunflower oil-based oleogels. Additionally, the application of these oleogels in bread was evaluated by substituting margarine with equal amounts of oleogels prepared with 3%, 5%, 8%, and 10% rice bran wax under 20 ℃ cooling. The results pertaining to the microstructure, crystal polymorph, oil-holding capacity, hardness, and thermal properties of the oleogel demonstrated that oleogels cooled at 20 ℃ exhibited a dense dendritic crystalline network with the presence of β' polymorphs. Elevated cooling temperatures increased the fractal dimension Db values (1.822±0.013~1.835±0.105). As the rice bran wax content increased, the crystalline network of oleogels became progressively denser, accompanied by significant increases (P<0.05) in Db values (1.053±0.104~1.783±0.023), hardness (10.43 g~256.12 g), and oil-holding capacity (48.33%~95.42%). Correspondingly, the melting/crystallization peak temperatures increased gradually. Fourier transform infrared spectroscopy confirmed the existence of van der Waals forces among the oleogel constituents. In relation to dough hardness and rheological properties, the hardness of doughs prepared with the oleogels was comparable to that of the butter-containing dough, while both the storage modulus (G') and loss modulus (G'') were lower than those of the butter-based dough. The oleogel containing 10% rice bran wax displayed a significantly higher relative content of β' polymorphs than other groups (P<0.05), and the resultant bread showed texture properties, specific volume, and crumb structure approaching those of the butter-containing bread. The L^*, a^*, and b^* values of the crust color for all oleogel-added breads were lower than those of the butter-containing bread, with minimal impact on the crumb color. In summary, the dense crystalline network structure and high β' polymorph content in wax-based oleogels are critical factors influencing bread quality.

To enhance the mechanical properties and moisture barrier performance of cassava starch (CS) films, this study employed peanut protein isolate (PPI) and gelatin (GL) as protein modifiers to prepare composite films with CS. The effects of protein sources and addition ratio (0:10, 1:9, 2:8, 3:7, 4:6, and 5:5) on the properties and microstructure of the composite films were systematically investigated. The results showed that both proteins demonstrated good compatibility with CS, effectively enhancing the mechanical properties, water barrier performance, and microstructure density of the films. In the PPI/CS composite film, the optimal mass ratio was 3:7. The moisture content, water solubility, water absorption, moisture absorption, and water vapor permeability of the film were reduced by 28.32%, 19.39%, 14.79%, 27.87%, and 11.98%, respectively, compared to those of the pure CS film. The elongation at break also increased from 53.39% to 82.16%. In the GL/CS composite film, the addition of GL primarily improved the tensile strength of the film. When the mass ratio of GL/CS was 4:6, the tensile strength increased from 2.36 to 4.44 MPa, and the water barrier properties were significantly improved (P<0.05). Scanning electron microscopy and X-ray diffraction analyses indicated that protein addition optimized the surface morphology and modified the crystalline structure of the films, whereas Fourier-transform infrared spectroscopy confirmed the formation of hydrogen bonds between protein and starch molecules. In summary, PPI/CS composite films are more appropriate for short-term packaging requiring high flexibility and moisture barrier performance, whereas GL/CS composite films are more suitable for food packaging applications requiring greater structural stability. Both composites demonstrate significant potential for application in the field of biodegradable packaging materials.

To explore the potential application value of soy oligopeptides (SOP) in wheat bread, low-field nuclear magnetic resonance spectrometer, rheometer, scanning electron microscopy (SEM), and Fourier-transform infrared spectrometer (FTIR) were used to investigate the effects of SOP (replacing wheat flour at 0.2%, 0.4%, 0.6%, 0.8%, and 1%) on the moisture distribution, rheological properties, microstructure, and secondary structure of protein in wheat dough. After baking the dough into bread, the effects of SOP on the specific volume, porosity, textural properties, and relative crystallinity of the bread were investigated. The results showed that when the replacement amount of SOP was 1%, compared with the blank control group, the free water content in the dough decreased by 1.71% (P<0.05). Rheological analysis revealed that the addition of SOP reduced the G' and G" values of the dough and increased its viscosity. Infrared spectrum showed that SOP increased the total content of ordered structures (β-sheets and α-helixes) by up to 7.35%, suggesting a promotion of dough protein transformation from disordered to ordered conformations. The addition of SOP significantly increased the specific volume and porosity of bread and reduced its hardness (P<0.05). When the substitution level was 0.4%, the hardness of the bread decreased by 42.27% compared to the control group, and the relative crystallinity decreased by 1.16% compared with the control. At this substitution level, the bread exhibited a more homogeneous and finer cellular structure, accompanied by a softer and more palatable texture. These findings demonstrate that SOP exerts a beneficial impact on bread quality under low substitution conditions.

This study investigated the effects of immersion freezing (IM) and air freezing (AF) on frozen dough properties and the quality of the resulting baked bread, aiming to provide a basis for the development and application of rapid freezing technologies in flour products. The study compared the effects of the freezing methods on the various characteristics of dough, including the freezing rate, rheological characteristics, water state, microstructure, free sulfhydryl group content, and secondary structure of gluten proteins, and the texture, hardness of the baked bread. The results showed that the freezing rate of the IM dough (1.67 ℃/min) was significantly higher than that of the AF dough (0.38 ℃/min), the elastic modulus (G') and viscous modulus (G'') were closer to fresh dough. Furthermore, IM dough contained 0.53% more strongly bound water and showed 0.09 μmol/g less free sulfhydryl groups compared to the AF dough. In the IM dough, the secondary structure of gluten proteins was more ordered and the gluten network was more continuous. Compared to AF bread, IM bread exhibited a 9.49% increase in porosity, a 4.56 cells/cm² increase in hole density, and a 0.09 mm² increase in average hole area. The hardness of IM bread was 125.00 N, closer to that of bread made from fresh dough. These results indicated that IM more effectively preserves dough quality by inhibiting ice crystal growth and reducing gluten network damage. Consequently, the characteristics of IM bread were closer to those of bread made from fresh dough, which had significant technical advantages.

With epigallocatechin gallate (EGCG) and four proteins (soy protein isolate, casein, egg white albumin, and β-lactoglobulin) as materials, one protein-EGCG non-covalent complex and three covalent complexes were prepared through mixing, coupling reaction, hydroxyl radical reaction, and enzymatic reaction, respectively in this study. Indicators (such as EGCG binding rate, antioxidant in vitro, and inhibition rate of aging enzymes) were detected to examine effects of protein type and combination mode on EGCG binding status and activities in vitro of protein-EGCG complexes, and their correlation between the activity in vitro and structural stability during the digestive process were determined. Results showed that when protein-EGCG complexes forming, abilities of EGCG to scavenge the free radical (DPPH· and OH·) and inhibit aging (tyrosinase and elastase inhibition) were enhanced differently with the varied protein type and the binding mode. Although having the largest EGCG binding amount (0.175~0.225 mg/mg Pro), casein-EGCG complexes were also discovered lower activities in vitro than complexes containing soy protein isolate and EGCG under the same combination mode. Activity of the protein-EGCG non-covalent complexes could be improved by the hydroxyl radical covalent reaction owing to their enhanced DPPH· scavenging rate and tyrosinase inhibition rate by more than 86.73% and 49.12% respectively, while effects of enzymatic reactions and alkali oxidation reaction were opposite. The activities in vitro of protein-EGCG complexes were found irrelevant to their EGCG binding amount, soy protein isolate-EGCG covalent complex prepared by hydroxyl radical reaction, was discovered to show a poor digestive stability (EGCG binding amounts ranging from 0.06 to 0.15 mg/mg Pro) but a superior extracellular antioxidant activity, confirming the inverse correlation between the extracellular activity and the structural stability to some extent.

To investigate the interaction mechanism between bovine serum albumin (BSA) and naringenin (Nar), as well as the impact on the stability of Nar, multi-spectroscopic techniques were initially utilized to study the quenching mechanism, binding constant, and binding site of the BSA-Nar complex. Subsequently, molecular dynamics simulations were conducted to explore the binding free energy, key residues, binding modes, and interactions. Finally, Nar/BSA nanoparticles (Nar/BSA NPs) were prepared, and the antioxidant activity and in vitro release properties were examined. The findings indicated that Nar could quench the intrinsic fluorescence of BSA through a static quenching mechanism. The BSA-Nar complex was primarily formed via hydrogen bonding and hydrophobic interactions, with a binding constant of 1.7×10⁴ L/mol and a binding free energy of -14.78 kcal/mol. The secondary structure of BSA was altered, with the α-helix content decreasing from 79.39% to 77.67%. There was approximately one binding site between BSA and Nar, and Nar binds to site I of BSA. Key residues Arg208, Ala212, Leu326, and Gly327 significantly contributed to the binding. Furthermore, after six days of storage, when the concentration was 40 µg/mL, the DPPH free radical scavenging rates of Nar/BSA NPs and Nar were 11.42% and 9.30%, respectively. Following 61 hours of simulated gastric fluid digestion, the release rates of Nar/BSA NPs and Nar were 62% and 79%, respectively. The corresponding release rates in simulated intestinal fluids were 86% and 89%, respectively. These results demonstrate that BSA can stably bind with Nar, and the antioxidant activity of Nar is significantly enhanced upon encapsulation with BSA. Additionally, the release rates of Nar in simulated gastric and intestinal fluids are slowed when encapsulated within BSA.

Objective: To explore the stabilization and modification mechanisms of Polysaccharide of Nostoc sphaeroides Kützing (PNSK) on nano-selenium particles (SeNP), and the changes in biological activity before and after modification. Method: Using polysaccharide of PNSK as the raw material, Polysaccharide of Nostoc sphaeroides Kützing nano-selenium particles (PNSK-SeNP) was prepared by the sodium selenite (Na₂SeO₃) and ascorbic acid (V_C) redox method. The structure of PNSK and PNSK-SeNP were characterized by UV-Vis spectroscopy, high-performance liquid chromatography, X-ray diffraction, infrared spectroscopy, and X-ray photoelectron spectroscopy. The antioxidant and anticancer activity of PNSK and PNSK-SeNP were comparatively analyzed. Results: The selenium content of PNSK-SeNP was 52.03±0.20 mg/g and the particle size was 166.83±4.51 nm. No obvious difference was observed in the molar ratio of monosaccharides of PNSK-SeNP before and after preparation. The presence of a Se 3d signal peak in the X-ray photoelectron spectroscopy of PNSK-SeNP, and the selenium element existed in the 0-valent state. Both infrared spectroscopy and X-ray photoelectron spectroscopy indicated that the main structure and functional groups of PNSK were preserved in PNSK-SeNP, and no new chemical bonds were formed between SeNP and PNSK. The antioxidant assay found that the IC₅₀ of PNSK and PNSK-SeNP for hydroxyl radical (·OH) were 4.45 and 0.55 mg/mL, respectively, and for 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid), diammonium salt radicals (ABTS⁺) were 4.58 and 0.79 mg/mL, respectively, and for the A549 lung cancer cells were 0.87 and 0.06 mg/mL, respectively. Meanwhile, the migration of A549 lung cancer cells could be effectively inhibited by PNSK-SeNP, and apoptosis could also be induced. A significant correlation between the selenium content of PNSK-SeNP and its antioxidant and anticancer effects were revealed by correlation analysis. Conclusion: Nano-selenium can be effectively stabilized by PNSK, and the in vitro antioxidant and anti-cancer activities of PNSK-SeNP can be significantly enhanced compared with PNSK.

Given the limitation of practical application caused by the poor gel properties of single gelatin, guar gum (GG), and low acyl gellan gum (LG) were used to modify the brown cattle hide gelatin. Different polysaccharide-protein composite gels were prepared by changing the proportion of GG and LG added to gelatin. The texture properties, surface hydrophobicity, intermolecular forces, sulfhydryl content, low-field nuclear magnetic resonance, infrared spectroscopy, fluorescence spectroscopy, and scanning electron microscopy were studied. The results showed that the texture characteristics were significantly improved after adding two kinds of polysaccharide gels. Compared with single gelatin, with the increase of the proportion of LG in the system, the surface hydrophobicity decreased by 59.96%, and with the increase in the proportion of GG, the total content of total sulfhydryl increased by 30.49%. The intermolecular force was mainly manifested as the decrease of covalent bonds and the increase of hydrogen bonds between the proteins, indicating that GG promoted the expansion of proteins and LG promoted the aggregation of proteins. Infrared spectroscopy showed that after modification, the content of random coils in the secondary structure of the gel system decreased, while β-sheets increased, leading to enhanced orderliness. After modification, the fluorescence intensity decreased, and the stability of the system was improved. When the addition ratio of GG to LG was 5:5, the fluorescence intensity decreased by 26.81% compared to the pre-modified condition. The microstructure showed that the addition of GG could make the three-dimensional network structure of the gel denser, and LG could promote the highly brittle hard skeleton. In summary, the weak characteristics of gelatin gel were effectively improved by GG and LG.