This study aimed to investigate the inhibitory effect and underlying mechanism of ethanol extract from Chrysanthemum morifolium. 'Boju' (CME) on atherosclerosis (AS). An AS model was established using ApoE⁻/⁻ mice, which were randomly divided into a model group, low-, medium-, and high-dose CME groups (50, 100, and 200 mg/kg), a positive control group (simvastatin 3 mg/kg), and a normal control group, with an intervention period of 12 weeks. The levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in serum, and the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β in serum were measured. Pathological changes were observed via Oil Red O staining of the aorta and hematoxylin-eosin (H&E) staining of the liver. The expressions of LXRα and ABCA1 in liver tissue and NF-κB p65 in the aorta were detected by qRT-PCR and Western blot. In in vitro experiments, a foam cell model was established by inducing RAW264.7 macrophages with ox-LDL, and the cells were divided into a control group, a model group, and low-, medium-, and high-dose CME groups (25, 50, and 100 μg/mL). Cell viability, foam cell rate, intracellular contents of TC, cholesteryl ester (CE), and free cholesterol (FC), as well as the expressions of genes and proteins related to relevant signaling pathways were detected. Additionally, the NF-κB inhibitor BAY11-7082 was used to verify the mechanism. The results showed that compared with the model group, CME significantly decreased the serum levels of TC, TG, and LDL-C, and increased the serum level of HDL-C (P<0.01). Pathological staining demonstrated that the low-, medium-, and high-dose CME groups could reduce aortic lipid deposition and hepatic steatosis in a dose-dependent manner. Furthermore, CME significantly upregulated the mRNA and protein expressions of LXRα and ABCA1 in liver tissue (P<0.01), with the protein level of LXRα upregulated from 0.31±0.04 in the model group to 0.91±0.06 in the high-dose CME group. In addition, CME reduced the protein expression of p-NF-κB p65 in the aorta and the serum levels of TNF-α, IL-6, and IL-1β (P<0.01), and the protein level of p-NF-κB p65 decreased from 1.85±0.18 in the model group to 0.92±0.11 in the high-dose CME group. Meanwhile, CME decreased the intracellular contents of TC and CE and the CE/TC ratio in RAW264.7 macrophages, thereby inhibiting foam cell formation. Moreover, it upregulated the expressions of PPARγ, LXRα, and ABCA1 and inhibited the activation of the NF-κB pathway, and no significant differences were observed in key indicators such as p-NF-κB p65, ABCA1, TC, CE, and CE/TC ratio between the high-dose CME group and the BAY11-7082 inhibitor group. These results indicated that AS could be significantly inhibited by CME through activating the LXRα/ABCA1 pathway to regulate cholesterol metabolism and inhibiting the NF-κB pathway to alleviate inflammatory responses.

This study investigated the antioxidant activity and stability of walnut peptide-metal chelates using walnut peptides (WP, Mw<1 kDa) as raw material. The antioxidant capacity of WP chelates with different metal ions prepared by coordination was systematically evaluated, followed by screening of optimal-activity chelates and comprehensive assessment of their antioxidant capacity and stability. Molecular docking was employed to identify the peptide segment exhibiting the strongest antioxidant capacity within walnut peptides and elucidate its specific binding interactions. Results showed that the walnut peptide-calcium chelates (WP-Ca) exhibited significantly enhanced antioxidant activity（P<0.05）, achieving 74.00%±0.54% DPPH and 85.27%±0.67% ABTS⁺ radical scavenging rates, surpassing other metal-ion chelates. WP-Ca also maintained high stability across various pH, temperatures, and simulated gastrointestinal digestion. Molecular docking identified NALVAPHY as the optimal peptide for DPPH chelation, with its antioxidant activity mediated by electrostatic interactions and hydrogen bonding with DPPH. This study provides theoretical support for valorizing walnut processing by-products and advances the development of novel metal-chelated peptide antioxidants, with particular implications for functional foods and nutraceuticals.

The combination of Nisin with active substances can broaden its antibacterial spectrum and endow the system with antioxidant capacity, thereby synergistically enhancing food preservation efficacy. Consequently, it attracted much attention in the field of food safety research. In particular, the construction of composite films using Nisin-based compounds as functional components through different film-forming methods (such as coating, casting, extrusion, and electrospinning, etc.) became a research hotspot in the field of food active packaging in recent years. This article begins with a brief introduction to Nisin and its antibacterial mechanism, followed by a comprehensive overview of the bioactive substances utilized in conjunction with Nisin and their synergistic effects. Then, the research progress of Nisin compounds active films in food preservation, specifically from the aspects of different film-forming techniques, is mainly reviewed. Furthermore, the limitations of the current research and the future development directions are summarized and discussed, with the expectation of providing a reference for the efficient application of Nisin in the field of food preservation.

To investigate the influence of lemongrass extract on the fishy odor of Yellow River carp, this study focused on the fishy smell value and thiobarbituric acid (TBA) and sensory score as evaluation indicators to optimize the deodorization process. Using the electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS) technology, combined with orthogonal partial least squares discriminant analysis, the volatile components before and after deodorization were analyzed. The results showed that under the conditions of LE concentration of 1.5%, material-liquid ratio of 1:5 (g:mL), and soaking time of 46 min, the fishy degree value and TBA value were the lowest, which were 1.248 points and 0.264 mg MDA/kg respectively. Electronic nose analysis showed that LE treatment had an inhibitory effect on fishy substances containing sulfur, alcohol, aldehydes and ketones. A total of 42 volatile flavor substances were identified by GC-IMS. Among them, the content of aldehyde compounds was the highest before deodorization, and it was significantly reduced by 76.62% after deodorization treatment. By using the relative odor activity value and the variable projection importance factor, the characteristic compounds of carp before deodorization were screened out as valeraldehyde, butyraldehyde, heptanaldehyde, propionaldehyde, 1-hexaldehyde-M, and 1-hexaldehyde-D. After deodorization treatment, the main characteristic aroma compounds were acetone and ethyl acetate, which could bring pleasant fruity and floral flavors to the fish body. In conclusion, lemongrass extract can effectively reduce the characteristic fishy smell of Yellow River carp and improve its overall flavor quality, providing a certain theoretical basis for its industrial application in aquatic product processing in the future.

Peptidoglycan (PG) is a class of microbial polysaccharides with the functions of immunomodulation, anti-tumor, anti-inflammation, adsorption and toxicity reduction, which mainly exists in the bacterial cell wall. Due to its unique biological functions and structural properties, it has attracted much attention in scientific research and practical applications, and is now widely used in many fields such as medical, aquatic, and food. This paper summarizes the research progress of peptidoglycan in terms of its structure, biosynthetic pathway, extraction, function and application. In terms of extraction, the traditional physical and chemical methods, enzyme digestion and the emerging combined extraction method are described, and the advantages and disadvantages of each method are analyzed. The potential link between the biological functions of peptidoglycan and bacterial pathogenicity and immunomodulation is explored in depth. The results and challenges in practical applications are discussed, and the broad prospects of peptidoglycan research in multiple fields are envisioned for the future. By reviewing the current status of peptidoglycan research from multiple perspectives, it provides a reference for the subsequent in-depth study of its properties and the expansion of its applications.

This study evaluated the effects of three freezing methods (traditional refrigerator freezing, RF, spiral tunnel freezing, SF, and liquid nitrogen immersion freezing, LF) on the flavor profile of shredded pork with green pepper dishes, using fresh samples as controls. Flavor analysis was performed using an electronic nose (E-nose) combined with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Multivariate statistical approaches including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and odor activity value (OAV) calculations were employed to characterize key flavor compounds. The E-nose results showed that the W1W sensor, which detected sulfur compounds, exhibited the strongest response, indicating a high concentration of sulfur-containing volatiles. GC-MS analysis identified 81 volatile compounds, with hexanal and camphene levels increasing significantly after freezing, while benzaldehyde and β-bisabolene decreased significantly (P<0.05). Through OAV and OPLS-DA analyses, 27 flavor-active compounds and 35 treatment-discriminatory volatiles were identified. Ten key compounds with both OAV>1 and variable importance in projection (VIP) >1 were determined to be critical for flavor, including benzaldehyde (almond-like) and 2,5-dimethylpyrazine (meaty and green pepper-like notes). Notably, RF treatment led to accumulation of off-flavor compounds like hexadecane and (Z)-2-decenal, while SF and LF treatments better preserved the fresh-like flavor profile. This study identifies the key flavor compounds in shredded pork with green pepper dishes and provides practical insights for maintaining flavor quality in preprepared foods through optimized freezing processes.

This study aimed to screen lactic acid bacteria (LAB) with high exopolysaccharide (EPS)-producing capacity from traditional yak yogurt in Western Sichuan, and to characterize the structure and functional properties of the EPS. Among 185 LAB strains isolated, Limosilactobacillus fermentum 197 was identified as a high EPS producer. The fermentation medium was optimized through single-factor experiments, and the EPS was purified using DEAE-52 and CL-6B column chromatography. The purified fraction EPS1 was structurally characterized by Fourier-transform infrared spectroscopy, gel permeation chromatography, and nuclear magnetic resonance, and its bioactivities were evaluated in vitro. The results showed that the optimal carbon and nitrogen sources for EPS production were maltose and soybean peptone, both at 40 g/L. After optimization, the EPS yield reached 1699.83±34.31 mg/L, representing a 5-fold increase compared to the original yield. The purified EPS1, with a yield of 15.07%, had a molecular weight of 2.11×10⁵ Da and was composed of rhamnose, arabinose, galactose, glucose, and mannose. It contained both α- and β-glycosidic bonds, exhibited a triple-helix structure, and displayed a flaky porous morphology under microscopy. In vitro assays demonstrated that EPS1 at 10 mg/mL exhibited scavenging rates against ABTS⁺, DPPH, and hydroxyl radicals of 57.07%, 46.54%, and 49.68%, respectively, and an α-amylase inhibition rate of 51.46%. This study reveals the relationship between the structure of EPS1 and its antioxidant and hypoglycemic activities, providing a theoretical basis for developing functional dairy products using LAB-derived EPS and offering new insights into the utilization of lactic acid bacteria resources from plateau pastoral areas.

This study aimed to investigate the effects of a nitrite composite substitute (NSCS) composed of several natural substances (0.03% monascus red, 0.04% Nisin, and 0.03% rosemary) on the eating quality, total bacterial count, nitrite residue, and other indices of yak meat sausages during storage (1, 3, 5, 7, and 9 d), and to clarify the substitution effect of NSCS on nitrite in minced meat products. Results showed that NSCS exerted positive effects on improving the eating quality of yak meat sausages, reducing the total bacterial count and nitrite residues by substituting nitrite. Specifically, on day 9, the NSCS-treated group exhibited the highest water-holding capacity (86.1%), which was 15.5% higher than that of the nitrite-treated group (P<0.05). The cooking loss rate of the NSCS-treated group was significantly lower than that of the nitrite-treated group (P<0.05), and also significantly lower than that of the control group except on day 7 (P<0.05). During the storage period of 1~9 d, there was no significant difference in the total bacterial count between the NSCS group and the nitrite group, and both were significantly lower than that of the control group (P<0.05). On day 1, the nitrite residue in the nitrite-treated group reached the maximum of 28.3 mg/kg, which was significantly higher than those in the NSCS-treated group and the control group (P<0.05). On day 9, the nitrite residue in the nitrite-treated group dropped to the minimum of 11.2 mg/kg. Meanwhile, there was no significant difference in nitrite residue between the NSCS-treated group and the control group. In conclusion, NSCS can replace nitrite to a certain extent in the processing of yak meat sausages. This finding provides important reference significance for the development of green and organic yak meat products, and also offers theoretical references for research on nitrite substitutes in other minced meat products.

Taking gray Sufu inoculated with Mucor UV-M2 as the research object, the changes of volatile metabolites, microorganisms and their correlation during fermentation of grag Sufu were explored. In this study, the quality of the fermentation process was comprehensively evaluated using physicochemical indexes and sensory assessment methods. The results confirmed that the fermentation process reached an optimal state after 40 days. Non-targeted volatile metabolomics analysis revealed significant variations in metabolites at different fermentation stages. Based on the odor threshold, 18 compounds with an odor activity value (OAV)>1 were evaluated. Among them, 11 compounds contributed to the aroma profile, including esters, aldehydes, and ketones, while 7 compounds were associated with unpleasant odors, mainly sulfur-containing compounds. Microbiological analysis demonstrated that the diversity of fungi and bacteria decreased significantly as the fermentation progressed. Through Spearman correlation analysis, it was found that the bacteria Tetragenococcus and Halanaerobium exhibited positive correlations with most volatile compounds with OAV>1, whereas Acinetobacter showed negative correlations with these compounds. Among fungi, Mortierella, Aspergillus, Malassezia, Botrytis, Penicillium, and Sagenomella were positively correlated with most of the compounds, while Actinomucor and Candida showed negative correlations. Furthermore, the results of redundancy analysis (RDA) indicated that, among bacteria, Weissella and other genera were positively correlated with salt content. In the fungal community, amino-acid nitrogen was positively correlated with Mortierella, salt content was positively correlated with Actinomucor, and pH was positively correlated with Kodamaea. These findings suggest that the quality indexes of gray Sufu are positively associated with the core microbial flora. Overall, the above results indicate a significant correlation between the aroma characteristics and the microbial community at different stages during the fermentation of gray Sufu. This study provides valuable references for enhancing the flavor quality of gray Sufu through microbial regulation techniques.