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.

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.

Exploring the xanthine oxidase (XOD) inhibitory peptide from Chlorella pyrenoidosa could provide a scientific basis for hyperuricemia prevention and treatment strategies, and promote the comprehensive utilization of microalgal protein resources. In this study, Chlorella pyrenoidosa was used as the raw material to extract proteins. With the XOD inhibition rate and the degree of hydrolysis (DH) as evaluation indicators, the optimal enzymatic hydrolysis conditions were optimized through single-factor and response surface experiments. Based on this, further analysis of XOD inhibitory peptide was conducted. The results showed that papain was the most suitable protease, and the optimal enzymatic hydrolysis conditions were pH7.0, hydrolysis temperature 48.0 ℃, hydrolysis time 4.0 h, enzyme dosage 2000 U/g, and substrate concentration 10 mg/mL. Under these conditions, the theoretical inhibition rate was 73.78%, and the actual inhibition rate reached 71.56%±0.51%. The amino acid composition of Chlorella pyrenoidosa XOD inhibitory peptide was reasonable, with essential amino acids, hydrophobic amino acids, and basic amino acids accounting for 43.17%, 45.07%, and 14.15% of the total, respectively. Additionally, they exhibited moderate stability under gastrointestinal digestion conditions, but their inhibitory activity decreased significantly under high temperature or strong acid/alkaline conditions. They were also relatively sensitive to metal ions such as Fe²⁺, Fe³⁺, Cu²⁺ and Mg²⁺. The relative molecular mass mainly concentrated below 1 kDa, and the ultrafiltered fraction with a molecular weight <3 kDa showed the highest XOD inhibitory activity, with an IC₅₀ of (5.23±0.68) mg/mL. This study provides a theoretical reference for the development and utilization of food-derived uric acid-lowering peptides.

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.

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.

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.

In recent years, with the popularization of the concept of healthy diet, foods with glycemic index (GI) less than or equal to 55 (low GI) have gradually become the focus of consumers' attention. Among them, low GI noodles is a staple food that can regulate the level of blood sugar after meals, which have the advantages of reducing post-meal blood sugar fluctuations, preventing cardiovascular disease, regulating insulin levels, and enhancing satiety. In this manuscript, the research status of low GI noodles in recent years are summarized. The concept, classification, measurement method and influencing factors of GI are briefly described firstly, and then the influence mechanism of different types of raw materials, raw and auxiliary materials and different processing methods on the texture characteristics, sensory evaluation and starch content of low GI noodles are discussed, mainly focuses on the effects of different types of products on the level of postprandial blood glucose. Finally, the development prospect of low GI noodles is anticipated, in order to provide a theoretical basis for future research and market application in this field.

This study developed a high-stability indicator film containing a roselle (Hibiscus sabdariffa) anthocyanin extract (RAE)-oxalic acid (OA) co-pigment indicator (RAO), investigated the stability of the RAO indicator and its effects on the structure and performance of the indicator film, and applied the film to monitor the freshness of channel catfish (Ictalurus punctatus). The results showed that the stability of the RAO indicator improved compared with single RAE indicator. Moreover, the film with the RAO indicator showed enhanced performance. The tensile strength and elongation at break of the indicator film increased from 16.10 MPa and 280.95% to 17.81 MPa and 349.45%, respectively. Its moisture content and water solubility decreased from 19.10% and 42.71% to 13.98% and 34.69%, respectively. Under conditions of 4 ℃, 45% humidity, and no light exposure, the RAO indicator film could be stored for up to 82 days (ΔE<5). When used for monitoring the freshness of channel catfish at 4 ℃, the indicator film changed from rose-red to yellow-gray as the fish spoiled, demonstrating its accuracy in monitoring the spoilage process and its great potential for freshness monitoring applications.

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.