Nine types of commercial brewing yeast commonly used in industrial production from different manufacturers were used in the fermentation of Cerasus humilis wine. The contents of alcohol, methanol and higher alcohols, flavonoids and polyphenols, amino acids and aroma components of Cerasus humilis wine fermented by different kinds of yeast were compared and analyzed. The results showed that the alcohol content, methanol, and higher alcohols of Cerasus humilis wine fermented by RV002 yeast were the lowest. The methanol content in the Cerasus humilis wine fermented by Spark yeast was the highest, at 173.07 mg/L. The sample fermented by S377 yeast had the highest content of higher alcohols, which was 323.97 mg/L. The polyphenol content in the SIHA yeast fermented sample was the lowest, at 50.69 mg/L, while the polyphenol content in the ICV yeast fermented sample was the highest, at 86.45 mg/L. The flavonoid content in the Cerasus humilis wine sample fermented by BV818 yeast was the lowest, at 22.08 mg/L. Compared with the unfermented Cerasus humilis juice, the total amino acid content of the wine fermented by different yeast strains decreased significantly, and the amino acid content of the wine fermented by BV818 yeast decreased the least. The total amino acid content of Cerasus humilis wine fermented by different yeast strains showed a significant decrease compared to unfermented Cerasus humilis juice, with the least decrease observed in the amino acid content of Cerasus humilis wine fermented by BV818 yeast. Except for SIHA yeast, there was relatively little difference in the aroma components of Cerasus humilis wine fermented by the other 8 yeast strains. Overall, the amino acid content and sensory score of the Cerasus humilis wine fermented by BV818 yeast were the highest, and the methanol and higher alcohol content did not exceed the standard, making it suitable for the fermentation of Cerasus humilis wine.

To improve the bioavailability of whey protein hydrolysates, the effects of different ultrasonic power treatments (100, 200, 300, 400 W) on the structural characteristics of whey protein were investigated, along with their effect on the degree of hydrolysis, peptide content, and α-glucosidase inhibitory activity of the hydrolysates. The results demonstrated that moderate ultrasound treatment expanded the whey protein structure. Compared to the untreated sample, at 300 W for 25 min, the intrinsic fluorescence intensity reached its peak, and the average particle size decreased by 62% (P<0.05). Additionally, surface hydrophobicity and free sulfhydryl content increased by 35% and 36%, respectively. Secondary structure analysis revealed a reduction in α-helix (42%) and β-sheet (20%) content, while β-turn and random coil increased by 26% and 77% (P<0.05), respectively. Scanning electron microscopy (SEM) further confirmed structural changes, showed a transition from large, rough-edged sheets to smaller, smooth-edged fragments. Lactiplantibacillus plantarum C11 was used to ferment whey protein after ultrasonic treatment. Compared with non-ultrasonic fermented whey protein, the degree of hydrolysis, peptide content and α-glucosidase inhibition rate were increased by 26%, 15% and 32% (P<0.05), respectively. Moderate ultrasonic pretreatment can enhance the α-glucosidase inhibitory activity of whey protein fermentation products, which provides a new strategy for synergistic preparation of whey protein bioactive peptides.

To explore the structure and mechanism of hypoglycemic activity in vitro of polysaccharides from Cornus officinalis. Using Cornus officinalis as raw material, the polysaccharides were extracted by ultrasonic water extraction. COP-1S, COP-2S, and COP-3S were obtained by sevage deproteinization, alcohol precipitation, DEAE-52, and Sephadex G-100 column chromatography purification. The hypoglycemic activities in vitro of the three polysaccharide components were evaluated. On this basis, the structures of the polysaccharides were characterized by molecular weight, monosaccharide composition, infrared spectroscopy, etc. The inhibition mechanism of COP-2S on α-glucosidase was explored by enzyme kinetics and fluorescence spectroscopy. The results of hypoglycemic activity showed that the three polysaccharide components had weak inhibitory activity on α-amylase, but significant inhibitory effects on α-glucosidase. The order of inhibitory ability was COP-2>COP-1>COP-3, and the IC₅₀ of COP-2 was 5.18 mg/mL. The average molecular weights of the three polysaccharides were 24.518×10³, 32.392×10³ and 66.417×10³ Da, respectively. The monosaccharide compositions all contained mannose, rhamnose, glucose, xylose and arabinose, but the composition ratios were different. The arabinose composition ratio in COP-1S was relatively high, and both COP-2S and COP-3S contained arabinose and galacturonic acid, but the composition ratio in COP-2S was higher. UV and IR spectra indicated that the three polysaccharides did not contain protein and nucleic acid, and all contained pyran ring structures. COP-2S and COP-3S contained both α and β configurations glycosidic bonds, while COP-1S was of β configuration. Circular dichroism spectroscopy showed that all three polysaccharides increased the β-turn and random coil ratios of α-glucosidase, while decreasing the β-folding ratio, However, only COP-1S increased the α-helix ratio. Enzyme kinetics analysis indicated that the inhibition type of COP-2S on α-glucosidase was mixed competitive inhibition, with an inhibition constant K_i of 0.2248 mg/mL. Fluorescence spectroscopy analysis showed that the quenching effect of COP-2S on α-glucosidase was static quenching, which was a kind of interaction mainly driven by hydrogen bonds and van der Waals forces. This experiment provided a certain theoretical basis for the development of high-value functional foods with hypoglycemic effects from Cornus officinalis.

Fish soup, using large yellow croaker and pickled potherb mustard as raw materials, was prepared by traditional boiling method and ultrasonic-assisted boiling method, respectively. The changes in flavor characteristics of fish soup during the boiling process were analyzed and compared by sensory evaluation, high performance liquid chromatography, electronic tongue and electronic nose techniques. The results showed that ultrasonic-assisted boiling significantly increased the contents of soluble protein, TCA-soluble peptides and amino nitrogen in the pickled potherb mustard-large yellow croaker soup, and the sensory scores of the soup in terms of umami, aroma and taste were all better than those of the traditionally boiled samples. Ultrasonic-assisted boiling obviously increased the total contents of flavor nucleotides, organic acids and free amino acids in the fish soup, reaching the maximum values of 57.99 mg/100 mL, 95.22 mg/mL and 121.02 mg/100 mL, respectively, after 90 min of boiling. The contents of sweet amino acids such as proline and serine in the ultrasonic group samples increased, while the contents of some bitter amino acids such as histidine, isoleucine and valine reduced. Electronic tongue analysis indicated that the bitterness of the ultrasonic group samples decreased, while the umami characteristics were significantly enhanced. Electronic nose analysis could effectively distinguish the odor differences between the ultrasonic and control group samples. In summary, ultrasonic-assisted boiling can effectively promote the release and degradation of flavor precursors in fish meat and potherb mustard, and reduce the formation of undesirable flavor components, thereby improving the overall flavor quality of the fish soup.

This study aimed to explore the effects of laminarin (LM) on the physicochemical properties of sweet potato starch (SPS) and pea starch (PS), and to reveal the interaction rules between LM and the two starches by measuring the interaction forces in the starch-LM mixed systems. Different concentrations of LM (0%, 1%, 2%, and 3%, w/v) were mixed with the two starches respectively. The changes in gelatinization and rheological properties were measured using a rapid viscosity analyzer and a rheometer, and the gel strength and interaction forces were analyzed using a texture analyzer. The results showed that LM could inhibit the leaching of amylose from SPS, while increasing the leached amylose content of PS. In terms of gelatinization properties, the addition of LM increased the gelatinization viscosity of SPS-LM and PS-LM mixed systems, while reducing the setback viscosity of SPS and increasing that of PS. In rheological properties, the addition of LM increased the fluid index (n value) of SPS, but for PS, the addition of high concentrations (2% and 3%) of LM could reduce its fluid index (n value). The addition of LM enhanced the resilience of SPS and PS, and significantly reduced the thixotropic loop area of both. The addition of LM increased the storage modulus (G') and loss modulus (G") of SPS and PS. LM had different effects on the physicochemical properties of the two different starches, which might be related to the interaction mode between LM and the starches. The interaction forces indicated that hydrogen bond forces were mainly present in the SPS-LM mixed system, while both hydrogen bond forces and electrostatic forces were present in the PS-LM mixed system. In conclusion, LM interacted with SPS via hydrogen bonding during gelatinization, significantly elevating viscosity and viscoelasticity. In contrast, PS-LM interactions involved both hydrogen bonds and electrostatic forces, synergistically enhancing pseudoplasticity, gel strength, and rheological properties (including setback value). This study provides a theoretical basis for the development of laminarin-starch products.

Given to the quality deterioration, nutrients loss and the reduction of processing characteristics of frozen surimi gels, the present study was conducted to prepare surimi gels with a dual-network microstructure based on the TGase-induced covalent cross-linking of MP and the non-covalent interaction of curdlan with myofibrillar proteins. Additionally, the freeze-thaw stability of the dual-network surimi gels was further investigated in terms of gel strength, WHC, rheological properties, and ice crystal morphology. The results suggested that the gel strength and WHC of the TG/C dual-network surimi gels (0.4% TGase and 1% curdlan) showed the smallest decreases of 24.38% and 9.29% after five freeze-thaw cycles, respectively, compared with control group. In addition, the TG/C dual-network surimi gels showed a small size and uniformly distribution of the ice crystals. Differential calorimetric analysis indicated that the TG/C dual-network surimi gels had the lowest freezable water content and gel eutectic point, which demonstrated that the microstructure ice suppression strategy based on the dual-network structure modulation could slow down the ice crystal growth-induced deterioration of the gel quality, and enhance the freeze-thawing stability of the gel. The results of this study can provide theoretical references for the development and design of high-quality surimi gels with stable freeze-thaw quality.

The structural modification of Rosa sterilis pomace soluble dietary fiber (RSDF) was performed through the sulfamic acid-N,N-dimethylformamide method to obtain sulfated Rosa sterilis pomace soluble dietary fiber (SSDF). The adsorption characteristics and mechanism of SSDF on nitrite, cholesterol, and three bile salts (sodium taurocholate, sodium glycochenodeoxycholate, and sodium cholate) were systematically investigated by analyzing adsorption kinetics and isothermal adsorption model under varying additions, including additive amount, adsorption times, and initial solution concentrations. The results showed that the sulfuric acid esterification modification significantly improved the adsorption capacity of SSDF for nitrite. At an addition amount of 100 mg, SSDF exhibited a higher adsorption amount (34.84 mg/g) and adsorption rate (68.94%) compared to RSDF (29.01 mg/g, 34.24%). For cholesterol adsorption, the difference between SSDF and RSDF was minimal. However, SSDF demonstrated superior performance within a short time (≤30 min). The adsorption of nitrite onto cholesterol by SSDF and RSDF was suitable to be fitted by quasi-secondary kinetics and Freundlich model. Furthermore, SSDF exhibited a better adsorption characteristic for cholate, especially for sodium cholate, achieving a maximum adsorption rate of 90.31%. The adsorption process was in accordance with the Freundlich model fitting (R²>0.9534). This study has the potential to provide theoretical insights into enhancing the adsorption capacity and utilization efficiency of soluble dietary fiber in Rosa sterilis pomace. Furthermore, these results can establish a scientific foundation for the application of sulfated modified dietary fiber in human health regulation.

This study aimed to explore the effects of combined gellan gum, carrageenan, and sodium alginate on polysaccharide composite gel properties, and evaluated their practical applications in food production. Single gels composed of gellan gum, carrageenan, or sodium alginate were prepared, alongside four composite gels formulated at ratios of 1:1:1, 2:1:1, 1:2:1, and 1:1:2. Gel properties were characterized by low-field nuclear magnetic resonance (LF-NMR), rheological analysis, differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results revealed that, compared to single-component gels, composite gels exhibited markedly improved water-binding capacities, as evidenced by shortened T₂₃ relaxation times, decreased A₂₃ values, increased storage modulus, and reduced freezeable water content. Among all samples, the 1:2:1 composite gel showed the lowest freezable water content (76.14%), which was reduced by 14.14%, 20.51%, and 23.01% compared to single gels of gellan gum, carrageenan, and sodium alginate, respectively. Additionally, FTIR analysis showed an increased amplitude at 3424 cm⁻¹ and a peak shift at 1637 cm⁻¹, and SEM images revealed dense and homogeneous network structures, confirming that interactions such as hydrogen bonding among these polysaccharides significantly enhanced gel properties and microstructural characteristics. Sensory evaluations conducted on suspension beverages formulated with composite gels revealed the ratio of 1:2:1 to be superior, as this particular composite gel formulation demonstrated enhanced stability compared to other tested ratios.

In this paper, the starches from two distinctive plants, namely, the starch from Haimen taro (AAS) and the starch from Wangqiao fruit taro (CSS), were used as raw materials. With commercial sweet potato starch (SPS) as control, the physicochemical properties and in vitro digestion characteristics were comparatively analyzed. Results showed that the purity of the three starches was relatively high. The amylose content of SPS (53.4%) was much higher than those of AAS (36.2%) and CSS (26.3%). Infrared spectroscopy analysis indicated that the values of short-range structural order index (R_1044/1022) of AAS and SPS were 0.91 and 0.92, respectively, which were significantly higher than that of CSS (0.79). X-ray diffraction results demonstrated that AAS was a typical A-type starch, while SPS and CSS were C_A-type starches. Scanning electron microscopy images revealed that AAS and CSS presented various shapes including spherical and irregular polyhedrons, with particle diameters of 6.1±1.9 μm and 3.1±1.2 μm respectively. Chain length distribution analysis revealed that the amylose molecular degree of polymerization of AAS was significantly lower than that of CSS and SPS. In the branched part, CSS had relatively more A chains and B1 chains, while SPS had the most B2 and B3 chains. In terms of physicochemical properties, the solubility, swelling power, and thermal stability of AAS and CSS starch gels were all lower than those of SPS. In vitro digestion characteristic analysis showed that before gelatinization, AAS contained approximately 22% rapidly digestible starch (RDS) and was the easiest to be digested. After gelatinization, SPS (containing approximately 30% RDS) was more resistant to the action of digestive enzymes, while the resistance to digestion of AAS and CSS was similar (both containing approximately 40% RDS). Therefore, AAS was an A-type starch with uniform particles at moderate particle size, and easy digestibility, while CSS was a C_A-type starch with smaller particles, slightly lower structural order, opaque starch paste, but better resistance to digestion. The research results can provide a reference for the development and application of these two new resource starches.

Terpenoids, as key secondary metabolites in Inonotus hispidus, possess significant medicinal value. However, their natural biosynthetic efficiency remains relatively low. The application of exogenous inducers was demonstrated to significantly enhance terpenoid production in this fungus. To elucidate the regulatory role and molecular mechanisms of exogenous oleic acid on triterpene metabolism, Inonotus hispidus was treated with 3% oleic acid, and its effects on mycelial growth, triterpene accumulation, and gene expression were systematically analyzed. Through metabolomics profiling, 23 differentially expressed terpenoid metabolites were identified, including seven triterpenoids, five diterpenoids, eight sesquiterpenoids, two monoterpenoids, and one undefined terpenoid. Transcriptomic analysis revealed 35 differentially expressed genes associated with terpenoid biosynthesis, consisting of one squalene oxygenase gene, nine terpene synthase (TPS) genes, and 25 cytochrome P450 (CYP450) genes. Further q-PCR validation confirmed that the expression of TPS-6618 was significantly upregulated by oleic acid, whereas the expression of CYP450-7867 was inhibited. This study elucidates the regulatory mechanism of oleic acid on terpenoid biosynthesis in Inonotus hispidus at both metabolic and gene expression levels, providing a theoretical foundation for understanding the molecular mechanisms of fungal terpenoid synthesis and the breeding of high-yield strains.