This study investigated the preparation of rice protein (RP)-ferulic acid (FA) complex via ultrasound-assisted treatment, exploring both covalent and non-covalent interactions. The structure of these complexes was characterized using polyphenol grafting equivalents, sulfhydryl content analysis, UV spectroscopy, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. Furthermore, the solubility, surface hydrophobicity, and antioxidant activity of the complexes were evaluated. The results demonstrated that the ultrasound-assisted covalent complex exhibited the highest polyphenol grafting equivalent, reaching 25.49 μg FA/mg. Complexation with FA reduced the fluorescence intensity of RP, whereas the ultrasound-assisted treatment of the RP-FA complex led to an enhancement in RP fluorescence. Compared to non-ultrasonic treatment, ultrasound processing decreased the relative content of α-helix by 5.46% and 3.41% for covalent and non-covalent complexes, respectively. In addition, protein solubility was enhanced by 25.85% and 8.13% for covalent and non-covalent complexes prepared by ultrasound processing, respectively. Both DPPH and ABTS⁺ free radical scavenging abilities were significantly improved, with increases of 9.75% and 3.72% for DPPH and 10.45% and 2.06% for ABTS⁺, respectively, for covalent and non-covalent complexes after ultrasound treatment. Ultrasonic-assisted treatment significantly promoted the complexation of RP and FA, altered the structure of the complexes, and enhanced their functional properties, providing technical references and theoretical support for the application of rice protein-phenol complexes in fields such as food antioxidants and functional ingredients.

To investigate the effects of different pretreatment methods on the drying rate and quality of vacuum freeze-drying chanterelles, this study systematically compared four techniques: microwave pretreatment (MP), blanching pretreatment (BP), osmotic pretreatment (OP), and hot air pretreatment (HP). The effects of these pretreatments were evaluated based on several indicators, including drying characteristics, microstructure, rehydration capacity, color difference, total phenol and flavonoid content, antioxidant capacity, free amino acid content, and volatile flavor composition. The results demonstrated that compared to the control group (which required 16 hours of drying), the drying durations of MP, BP, OP, and HP were shortened to 13, 11, 11, and 13 hours, respectively. MP, BP, and OP significantly damaged the cellular structure of chanterelles, resulting in reduced levels of total phenols, total flavonoids, antioxidant activity, and free amino acids. In contrast, HP better preserved the tissue structure and led to increases in total phenol content, DPPH radical scavenging activity, ABTS⁺ radical scavenging activity, and free amino acid content by 12.33%, 30.38%, 51.15%, and 59.86%, respectively. Furthermore, the number of volatile flavor compounds increased by 8, 4, and 4 types in the HP, BP, and OP groups, respectively. However, the total content of volatile flavor compounds declined in MP, BP, and OP, with only HP exhibiting an overall increase. Notably, key flavor constituents such as 1-octene-3-ol, trans-2-octenal, and 2-pentylfuran increased by 13.32%, 332.03%, and 184.44%, respectively. In terms of product quality, the rehydration capacity and color retention of chanterelles subjected to HP and MP were superior to those treated with BP and OP. Overall, hot air pretreatment (HP) emerged as the more effective pretreatment method for vacuum freeze-drying chanterelles, providing a valuable reference for improving the quality and industrial processing of dried edible fungi.

In order to explore the effect of salt reduction and umami enhancement of the MFP₃-D (freeze-dried powder obtained with ultra-high pressure treatment liquid of Mercenaria mercenaria) on the sauce with yam and clam. The MFP₃-D was used to replace the edible salt in sauce with yam and clam in different ratios (0:2, 1:2, 1:3, 1:1, 3:1, 2:0) (numbered group S0, S1, S2, S3, S4, S5, respectively). The results showed that with the increasing of MFP₃-D, the salt content of the products showed a significant decreasing trend (P<0.01), compared with the control group S0, the saltiness of group S5 was significantly lower than that of S0 (P<0.05), while the saltiness of group S4 showed no significant difference with that of S0 (P>0.05), the umami of group S2, S3, S4, S5 was significantly higher than that of S0 (P<0.01), and the umami of group S4, S5 was the highest. Compared with control group S0, the contents of glutamic acid and aspartic acid of group S4 which play a role in enhancing umami were significantly increased (P<0.001), the contents of volatile substances such as butyraldehyde, ethyl acetate, and 2-butanone which play a role in presenting a good aroma and enhancing the perception of salty and umami flavors were increased. In conclusion, the group S4 can not only achieve the objective of reducing salt and enhancing umami, but also enrich the aroma of the sauce with yam and clam.

To investigate the inhibitory effect and mechanism of sea buckthorn extract (SBE) on α-amylase, and to evaluate the influence of acarbose and casein on its inhibitory activity, SBE was prepared using ultrasound-assisted extraction. The inhibitory activity and underlying mechanism were systematically studied through enzyme inhibition assays, enzyme kinetics analysis, fluorescence quenching spectroscopy, and molecular docking, and were complemented by combined inhibition assays and casein-SBE interaction analyses to assess its performance when used with acarbose and under the presence of casein.The results showed that SBE exhibited significant inhibitory activity against α-amylase, with an IC₅₀ value of 88.9±1.2 μg/mL. The inhibition type was identified as mixed-type, involving both competitive and non-competitive modes, and the inhibitory effect of SBE was superior to that of acarbose. Fluorescence quenching analysis revealed that SBE spontaneously formed a complex with α-amylase, altering the microenvironment of the enzyme's chromophores and leading to intrinsic fluorescence quenching, thereby reducing enzymatic activity. Molecular docking further confirmed that the active compounds in SBE could form stable interactions with amino acid residues of α-amylase. Combined inhibition experiments indicated an additive effect between SBE and acarbose. Moreover, casein was found to reversibly interfere with the inhibitory activity of SBE. These findings provide a theoretical basis for the potential development of SBE as a natural α-amylase inhibitor.

To develop a novel carrier for mineral delivery, sodium alginate-albumen composite gel beads (SA-A) were prepared using sodium alginate and albumen as substrates, and further iron-loaded composite gel beads (SA-A-Fe) were synthesized. The physicochemical properties and Fe³⁺ loading capacity of the beads were evaluated through structural characterization. Results revealed that the binding between sodium alginate and albumen was governed by non-covalent interaction. Compared to pure sodium alginate beads (SA), the SA-A beads exhibited markedly enhanced viscoelasticity and thermal stability, with both viscoelastic and thermal properties further improved upon Fe³⁺ loading. The adsorption of Fe³⁺ was more in line with the pseudo-second-order kinetic model, indicating that chemisorption could be considered as the dominant mechanisms of Fe³⁺ adsorption. In the first adsorption stage of the intraparticle diffusion model, the rapid diffusion of Fe³⁺ from the aqueous phase to the bead surface was identified as the rate-limiting step, followed by gradual intra-particle diffusion until equilibrium was attained. The adsorption process was characterized by heterogeneous surface sites and multilayer adsorption behavior. In vitro release studies demonstrated that the SA-A bead, as a wall material, effectively delayed premature Fe³⁺ release in simulated gastric fluid while promoting sustained release under simulated intestinal conditions, demonstrating that the SA-A-Fe gel beads possess unique sustained-release characteristics and good stability. Collectively, these findings demonstrate that SA-A beads possess excellent structural integrity and high Fe³⁺ loading efficiency, with controlled iron ion release under simulated gastric and intestinal fluid conditions, highlighting their promise as an effective carrier for iron delivery. This work provides a scientific foundation for the rational design and application of novel iron supplements.

In this study, a total of 64 lactic acid bacteria (LAB) strains were isolated from the surface of Phyllanthus emblica. The tannase activity, growth characteristics, tolerance to acid, bile salts, and artificial gastrointestinal fluids, as well as their antibacterial ability of these strains were investigated. Four dominant lactic acid bacterial strains were selected. Through 16S rDNA molecular identification, strains YG-10, YG-8, and YG-6 were identified as Pediococcus pentosaceus, while strain YG-16 was identified as Lactobacillus brevis. Among them, strain YG-10 exhibited a tannase activity of 68.84 U/mL. The survival rates of the strain under pH2.0 and 0.4% bile salt stress were 89.79% and 60.72%, respectively. After 3 hours of incubation in simulated gastric fluid and 4 hours in simulated intestinal fluid, the survival rates were 89.13% and 50.58%, respectively. The strain also showed strong antibacterial activity against Escherichia coli, Staphylococcus aureus and Salmonella. When YG-10 was used to ferment Phyllanthus emblica juice, the degradation rate of tannic acid reached 75.14%, the astringency was weakened, and meanwhile, the characteristic lingering sweetness was retained. This study was the first to screen tannase-producing LAB from the surface of Phyllanthus emblica, which possessed the functions of de-astringency, nutritional enhancement, and probiotic properties. It could provide new resources and technical support for the screening of tannase-producing strains and the development of functional fermented beverages.

To investigate the roles of 6-methoxy-benzoxazolin-2-one (MBOA) and benzoxazolin-2-one (BOA) in the health-promoting effects of whole-grain foods, this study evaluated their in vitro antioxidant capacity and modulatory effects on gut microbiota. The results demonstrated that while MBOA and BOA exhibited dose-dependent antioxidant activity, their efficacy was inferior to that of ferulic acid. Compared to equivalent doses of ferulic acid, MBOA, BOA, and the mixture significantly enhanced microbial diversity in a dose-dependent manner, with the mixture showing optimal efficacy. At the phylum level, these compounds significantly reduced the relative abundances of Proteobacteria and Bacteroidetes while increasing those of Firmicutes and Actinobacteria. At the genus level, they markedly elevated the relative abundances of Bifidobacterium and reduced Escherichia, Prevotella, and Bacteroides. This study indicates that MBOA and BOA in whole grains possess substantial prebiotic potential.

In order to expand the reservoir of highly active agarase-producing strains and to mine agarase-related gene pools, this study isolated strains from abalone viscera. Primary screening was conducted using a single carbon source medium combined with Lugo's iodine staining, followed by rescreening via the 3,5-dinitrosalicylic acid (DNS) method to determine enzyme activity. Agarase-producing strains were identified by 16S rDNA sequencing, and their genomic sequences and enzymatic properties were compared. Four strains of Vibrio mediterranei (2DB7, 2DB15, 2DBB20 and 2DBB51) producing highly active agarases were screened. The activities of the crude enzyme solutions from these strains were 315.17, 340.99, 293.88, and 324.37 U/mL, respectively. Whole genome sequencing revealed that 2DB15, 2DBB20, and 2DBB51 encode relatively abundant agarase genes and related enzyme genes, including β-agarases (GH16 and GH50 families), β-galactosidase, and α-neoagarobiose hydrolase. The agarases produced by these four strains (2DB7, 2DB15, 2DBB20 and 2DBB51) reached their peak relative activity at 45, 40, 45, and 45 ℃, and at pH 8.0, 7.0, 8.0, and 7.0, respectively. Furthermore, all enzymes maintained good stability below 40 ℃ and within a pH range of 5.0 to 9.0. The research results could enrich the theoretical foundation for agarase production by Vibrio sp. and provide high-quality enzyme resources for the eco-friendly production of agar oligosaccharides.

The aim of this study was to explore potential probiotic resources in traditional cereal-fermented beverages in Xinjiang. To this end, strains of lactic acid bacteria were isolated from traditional cereal-fermented beverages and their probiotic properties were characterized. Repetitive polymerase chain reaction profiles and 16S rRNA gene sequencing identified 21 isolates of lactic acid bacteria in seven species from 12 traditional cereal-fermented beverages. Limosilactobacillus fermentum was the dominant species, followed by Lacticaseibacillus paracasei. All 21 strains of lactic acid bacteria had antioxidant activity, with particularly strong scavenging of superoxide anion radicals. In terms of antibacterial ability, all strains, except Companilactobacillus paralimentarius HLB2-4, effectively inhibited the development of at least six pathogenic bacteria, demonstrating broad-spectrum antibacterial activity. After continuous treatment with simulated gastric fluid for 3 h and simulated intestinal fluid for 8 h, seven strains had strong tolerance, with Lactiplantibacillus plantarum THB1-1 having the highest survival rate (38.15%). The hydrophobicity of the 21 strains ranged from 7.36% to 76.46%, and their auto-aggregation rates after 4 h ranged from 4.62% to 67.09%. There were significant differences in hydrophobicity and auto-aggregation among the strains (P<0.05). These results were used as inputs for principal component analysis and clustering analysis, which showed that six strains, Lactobacillus paracasei YTJ1-4, TXJ2-1, Limosilactobacillus fermentum TXJ2-4, Lactobacillus acidophilus HZK2-4, Lactiplantibacillus plantarum THB1-1, and Levilactobacillus brevis MTB1-5 were the most promising probiotics. This study lays the groundwork for the development, utilisation, and industrial application of probiotics from traditional cereal-fermented beverages in Xinjiang.

In order to investigate the effects of chili peppers on volatile compounds and bacterial community composition in shrimp paste, this study applied chili peppers to the fermentation of shrimp paste and compared it with the fermented shrimp paste without chili peppers, determined volatile compounds by gas chromatography-ion mobility spectrometry (GC-IMS), and analyzed the phylum- and genus-level compositions of the bacterial community and the changes in diversity by high-throughput sequencing (HTS). Besides, this study established the correlation between dominant genera and key volatile flavor compounds by Spearson correlation analysis (SCA). The results showed that the addition of chili peppers increased the malondialdehyde content of shrimp paste during the fermentation process, and the flavor differences between the two groups of shrimp paste at the end of fermentation were small and acceptable. The addition of chili peppers introduced volatile flavor compounds such as 2-ethylfuran, β-pinene M, methyl tert-butyl ether D, 2,3-diethylpyrazine M, and propionaldehyde into the shrimp paste. As fermentation proceeded, flavor compounds such as 2,3-pentanedione and 2-methylbutyraldehyde accumulated in the chili shrimp paste, and methyl tert-butyl ether, β-pinene, and other substances with some irritating odors decreased, resulting in a softer flavor. At the phylum level, the addition of chilli peppers increased the relative abundance of Cyanobacteriota and Bacillota and decreased the relative abundance of Bacteroidota in shrimp paste. At the genus level, the addition of chilli peppers introduced Oceanobacillus to the shrimp paste, increased the relative abundance of norank_o_Chloroplast, and decreased the relative abundance of Olleya and Flavobacterium. Candidatus_Bacilloplasma, unclassified_f_Paracoccaceae, as the core dominant genera shared by the two groups of shrimp paste, were significantly negatively correlated with the content of characteristic volatile compounds in chili peppers, such as 2-ethylfuran, and were also positively correlated with the major volatile flavor compounds generated in shrimp paste fermentation, such as butyl acrylate M, which were a key microorganism driving the formation of flavor. The results of this study provide theoretical support for the development of novel flavor composite chili peppers shrimp paste.