ABSTRACT
Herein, three types of ovalbumin (OA)-polysaccharide conjugates were prepared with three polysaccharides (XG: xanthan gum; GG: guar gum; KGM: konjac glucomannan) for the fish oil emulsion stabilization. The glycation did not change the spectra bands and secondary structure percentages of OA, whereas it decreased the molecular surface hydrophobicity of OA. The initial emulsion droplet sizes were dependent on the polysaccharide types, OA preparation concentrations, polysaccharide: OA mass ratios, and glycation pH. The emulsion stability was mainly dependent on the polysaccharide types, polysaccharide: OA mass ratios, and glycation pH. However, it was minorly dependent on the OA preparation concentrations. The emulsions stabilized by conjugates with high polysaccharide: OA mass ratios (e.g., ≥3:5 for OA-GG) or appropriate glycation pH (e.g., 5.0-6.1 for OA-XG) showed no obvious creaming during the room temperature storage. This work provided basic knowledge on the structural modification and functional application of a protein.
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Polysaccharides are widely used to improve the quality of plant-based meat analogue (PMA). In this study, four kinds of konjac glucomannan (KG) with different deacetylation degrees (DD) were prepared, namely KG1 (native KG, DD = 0.00 %), KG2 (DD = 41.40 %), KG3 (DD = 80.01 %) and KG4 (DD = 89.07 %), and their effects on the quality of PMA were studied. Results manifested that KG3 improved the hardness (from 3017.16 g to 3307.16 g) and protein digestibility (from 49.65 % to 53.01 %) of PMA without reducing the P21, KG2 and KG4 were less effective than KG3, while KG1 led to a significant decline in the hardness and protein digestibility of PMA. The rheological properties and intermolecular force analysis showed that the partially deacetylated KG was more conducive to improving the G' of the protein system during heating and the proportion of covalent bonds in PMA. These findings suggested that partially deacetylated KG was more promising than native or highly deacetylated KG in PMA. Furthermore, scanning electron microscopy revealed that the morphology of KG gradually changed from fine filaments, to coarse filaments, short filaments and granules as DD increased. This study provides a theoretical basis for the application of partially deacetylated KG in PMA.
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The synergistic interaction gels (SIGs) can be created by blending konjac glucomannan (KGM) and κ-carrageenan, and have been applied to modify and improve the rheological and texture properties of food system. However, the assembly behaviors between them are still unclear. This work revealed that the presence of KGM promoted phase transition of nearby κ-carrageenan molecules probably by contributing to entropy increment. Subsequently, the rest of κ-carrageenan transformed into helical structure, assembled into a series of laterally arranged trigonal units and formed a three-dimensional network. In KGM/κ-carrageenan SIGs, the size of high density domains (Ξ) in aggregates and the distance of these high density domains (ξ) were narrowed firstly and then enlarged as increasing of KGM content. These nano-scale structure features were responsible for the relative higher gel strength for KGM/κ-carrageenan SIGs with proportion ratios of 1:9 (K1C9) and 3:7 (K3C7). This study serves to facilitate the design and production of SIGs with the requisite performance characteristics.
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The study aimed to create a fish-derived protein gel with inulin/konjac glucomannan (KGM) mixture for dysphagia. The inulin/KGM complex improved the swallowing properties of myofibrillar protein (MP) emulsion gel. Interactions, physicochemical, and flavor properties were analyzed. Inulin/KGM mixture inhibited hydrophobic groups exposure, and maintained MP structure during thermal induction. Inulin/KGM-protein gels exhibited shear-thinning behavior, low deformation resistance and hardness. IDDSI test also indicated inulin/KGM gels is suitable for dysphagia. Inulin/KGM mixture improved flavor by increasing ethanol and 2-octen-ol while decreasing ichthyological substances such as hexanal and nonanal, enhancing the sensory experience of patients with dysphagia. An 8% inulin/KGM mixture effectively modulated mechanical, swallowing, and sensory properties of MP emulsion gels, offering insights for future marine-derived dysphagia foods development.
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In this study, different proportions of curcumin (CUR) and alizarin (ALI) were added to konjac glucomannan (KG)/ polyvinyl alcohol (PVA) to prepare an active intelligent packaging film and evaluate its potential to indicate pork freshness. The mixed indicator had a richer color hierarchy in the buffer solution with pH=2-12. The surface of the KG-2C2A and KG-1C3A films is smoother and has fewer cross-section faults. With the increase of CUR content in the film, the crystal structure becomes more prominent, leading to poor compatibility with KG. The WAC of KG-3C1A and KG-1C3A films was significantly higher than that of the other groups, and they had better hydrophobicity. With the increase of CUR content in the films, the thermal stability of the films was enhanced, and the KG-C films showed the highest thermal stability. Among them, the KG-2A2C and KG-1C3A films showed the most significant color change during pork spoiling and could be used to monitor the freshness of pork. As a pH colorimetric indicator, CUR and ALI coated KG films might be of great potential in fresh meat monitoring.
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Pasteurization, as a meaningful part of food processing, has received growing attention for regulating Pickering emulsion stability. In this research, the role of pasteurization and konjac glucomannan (KGM) in the modulation of Pickering emulsion properties was investigated. The results showed that the network structure formed by KGM inhibited the agglomeration of droplets due to pasteurization, which improved the heat stability of the Pickering emulsion. Increasing the concentration of KGM improved the densification of its network structure, as evidenced by the enhanced viscoelasticity of the emulsion after pasteurization. The retention rate of ß-carotene encapsulated in the Pickering emulsion could reach 99% after pasteurization at 65 °C for 30 min. Moreover, pasteurization further enhanced the inhibitory effect of KGM on free fatty acid release and implemented a manageable release of ß-carotene. This research offers theoretical guidance for the construction of highly stable Pickering emulsions for delivering temperature-sensitive hydrophobic ingredients.
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BACKGROUND: Effective treatments for the alveolar bone defect remain a major concern in dental therapy. The objectives of this study were to develop a fibrin and konjac glucomannan (KGM) composite hydrogel as scaffolds for the osteogenesis of nasal mucosa-derived ectodermal mesenchymal stem cells (EMSCs) for the regeneration of alveolar bone defect, and to investigate the osteogenesis-accelerating effects of black phosphorus nanoparticles (BPNs) embedded in the hydrogels. METHODS: Primary EMSCs were isolated from rat nasal mucosa and used for the alveolar bone recovery. Fibrin and KGM were prepared in different ratios for osteomimetic hydrogel scaffolds, and the optimal ratio was determined by mechanical properties and biocompatibility analysis. Then, the optimal hydrogels were integrated with BPNs to obtain BPNs/fibrin-KGM hydrogels, and the effects on osteogenic EMSCs in vitro were evaluated. To explore the osteogenesis-enhancing effects of hydrogels in vivo, the BPNs/fibrin-KGM scaffolds combined with EMSCs were implanted to a rat model of alveolar bone defect. Micro-computed tomography (CT), histological examination, real-time quantitative polymerase chain reaction (RT-qPCR) and western blot were conducted to evaluate the bone morphology and expression of osteogenesis-related genes of the bone regeneration. RESULTS: The addition of KGM improved the mechanical properties and biodegradation characteristics of the fibrin hydrogels. In vitro, the BPNs-containing compound hydrogel was proved to be biocompatible and capable of enhancing the osteogenesis of EMSCs by upregulating the mineralization and the activity of alkaline phosphatase. In vivo, the micro-CT analysis and histological evaluation demonstrated that rats implanted EMSCs-BPNs/fibrin-KGM hydrogels exhibited the best bone reconstruction. And compared to the model group, the expression of osteogenesis genes including osteopontin (Opn, p < 0.0001), osteocalcin (Ocn, p < 0.0001), type collagen (Col , p < 0.0001), bone morphogenetic protein-2 (Bmp2, p < 0.0001), Smad1 (p = 0.0006), and runt-related transcription factor 2 (Runx2, p < 0.0001) were all significantly upregulated. CONCLUSIONS: EMSCs/BPNs-containing fibrin-KGM hydrogels accelerated the recovery of the alveolar bone defect in rats by effectively up-regulating the expression of osteogenesis-related genes, promoting the formation and mineralisation of bone matrix.
Subject(s)
Bone Regeneration , Fibrin , Hydrogels , Mannans , Mesenchymal Stem Cells , Osteogenesis , Phosphorus , Rats, Sprague-Dawley , Tissue Scaffolds , Animals , Bone Regeneration/drug effects , Rats , Mannans/pharmacology , Mesenchymal Stem Cells/drug effects , Osteogenesis/drug effects , X-Ray Microtomography , Nanoparticles , Nasal Mucosa , Alveolar Process , Male , Bone Morphogenetic Protein 2 , Core Binding Factor Alpha 1 Subunit , OsteocalcinABSTRACT
The convergence of polymer and pharmaceutical sciences has advanced drug delivery systems significantly. Carbohydrate polymers, especially carboxymethylated ones, offer versatile benefits for pharmaceuticals. Interpenetrating polymer networks (IPNs) combine synthetic and natural polymers to enhance drug delivery. The study aims to develop IPN beads using sodium carboxymethyl cellulose (SCMC) and carboxymethyl konjac glucomannan (CMKGM) for controlled release of ibuprofen (IB) after oral administration. Objectives include formulation optimization, characterization of physicochemical properties, evaluation of pH-dependent swelling and drug release behaviors to advance biocompatible and efficient oral drug delivery systems. The beads were analyzed using SEM, FTIR, DSC, and XRD techniques. Different ratio of polymers (CMKGM:SCMS) and crosslinker concentrations (2&4â¯%w/v) were used, significantly impacting bead size, swelling, drug encapsulation, and release characteristics. DSC results indicated higher thermal stability in IPN beads compared to native polymers. XRD revealed IB dispersion within the polymer matrix. IPN beads size ranged from 580⯱â¯0.56 to 324⯱â¯0.27⯵m, with a nearly spherical shape. IPN beads exhibited continuous release in alkaline conditions (pHâ¯7.4) and minimal release in acidic media (pHâ¯1.2). These findings suggest that the formulated IPN beads can modulate drug release in both acidic and alkaline environments, potentially mitigating the gastric adverse effects often associated with oral administration of IB.
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The impact of konjac glucomannan (KGM)-based synbiotics on yogurt quality is not well understood. This study investigated the effects of a synbiotic mixture of KGM and the selected probiotic Lactiplantibacillus plantarum SHY130 on the physicochemical, antioxidant, and sensory properties of yogurt. The results showed that KGM significantly promoted the growth of Lactiplantibacillus plantarum SHY130. The synbiotics dramatically enhanced the count of lactic acid bacteria in yogurt during the 14 days of storage. Texture analysis indicated that the synbiotic supplement had no impact on springiness and cohesiveness but resulted in notable reductions in hardness, gumminess, and chewiness. The synbiotics did not significantly affect the water-holding capacity and syneresis. While the synbiotics initially decreased yogurt viscosity, it increased with storage time. Furthermore, the synbiotics significantly improved the yogurt's antioxidant capacity. Additionally, the supplementation of the synbiotics did not adversely affect sensory properties, although the synbiotics containing 0.02% KGM negatively impacted overall acceptability. Overall, these findings elucidate the effects of KGM-based synbiotics on yogurt quality, providing a foundation for developing novel synbiotic yogurt products.
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Dietary fiber targets the regulation of the intestinal flora and thus affects host health, however, the complex relationship between these factors lacks direct evidence. In this study, the regulatory effects of Konjac glucomannan (KGM) on key metabolites of host intestinal flora were examined by using in vitro fermentation. The results showed that KGM could be utilized by the intestinal flora, which inhibited the relative abundance of Paeniclostridium, Lachnoclostridium, Phascolarctobacterium, and Bacteroides and enriched the relative abundance of Desulfovibrio, Sutterella, etc. Fermentation is accompanied by the production of short-chain acids, including acetic and propionic acids. Metabolomics revealed that KGM significantly promoted amino acid metabolism, lipid metabolism, and the biosynthesis of other secondary metabolites. Correlation analysis results showed that the increase of panose and N-(1-carboxy-3-carboxanilidopropyl) alanylproline content was positively correlated with the relative abundance of Megamonas. These results provide evidence that KGM affects host health by regulating gut microbiota and its metabolites.
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The properties and structure of gluten protein with different deacetylation degrees of konjac glucomannan (KGM) were investigated, in an attempt to improve the quality of gluten protein in flour products. Results showed that deacetylated KGM (DKGM) could improve the textural properties and enhance the thermal stability of gluten protein. DKGM increased the water holding capacity and shortened the T2 relaxation time of gluten after removing some acetyl groups. As the deacetylation degree increased, the hardness and adhesiveness of gluten gels gradually increased, while the springiness decreased. In addition, the presence of DKGM promoted the conversion from free sulfhydryl to disulfide bonds and increased the ß-sheet content in gluten protein. The low-deacetylation KGM decreased the surface hydrophobicity and fluorescence intensity of gluten protein, and the microstructures of gluten gels became more compact. Compared with gluten protein-KGM complex gel, the degradation temperature of gluten protein-DKGM complex gels was observed to increase by >3 °C. Overall, the low-deacetylation KGM was beneficial for improving the physicochemical properties and maintaining the network structure of gluten protein. This study provides valuable references and practical insights to improve gluten quality in the flour industry.
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The ideal physicochemical properties of bigels are important for food applications. Therefore, a new bigel was prepared based on mixed beef tallow and soybean oil oleogel and deacetylated konjac glucomannan (KGM) hydrogel. The effect of the deacetylation degree of KGM on the physicochemical properties and microstructure of bigels was studied. The bigel containing moderate deacetylation degree of KGM had better rheological properties and hardness (319.84 g) than that with low and high deacetylation degrees of KGM. The interactions among the bigel components were analyzed by Fourier transform infrared spectroscopy and molecular dynamics simulation, indicating that the formation of the bigels was dominated by electrostatic interactions. Overall, the bigels containing moderate deacetylation degree of KGM had better physical properties, which may provide a theoretical foundation to develop bigels with low cholesterol, trans and saturated fats levels to replace traditional solid fats in food industry.
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Konjac glucomannan (KGM), high-viscosity dietary fiber, is utilized in weight management. Previous investigations on the appetite-suppressing effects of KGM have centered on intestinal responses to nutrients and gastric emptying rates, with less focus on downstream hypothalamic neurons of satiety hormones. In our studies, the molecular mechanisms through which KGM and its degradation products influence energy homeostasis via the adipocyte-hypothalamic axis have been examined. It was found that high-viscosity KGM more effectively stimulates enteroendocrine cells to release glucagon-like peptide-1 (GLP-1) and reduces ghrelin production, thereby activating hypothalamic neurons and moderating short-term satiety. Conversely, low-viscosity DKGM has been shown to exhibit stronger anti-inflammatory properties in the hypothalamus, enhancing hormone sensitivity and lowering the satiety threshold. Notably, both KGM and DKGM significantly reduced leptin signaling and fatty acid signaling in adipose tissue and activated brown adipose tissue thermogenesis to suppress pro-opiomelanocortin (POMC) expression and activate agouti-related protein (AgRP) expression, thereby reducing food intake and increasing energy expenditure. Additionally, high-viscosity KGM has been found to activate the adipocyte-hypothalamus axis more effectively than DKGM, thereby promoting greater daily energy expenditure. These findings provide novel insights into the adipocyte-hypothalamic axis for KGM to suppress appetite and reduce weight.
Subject(s)
Adipocytes , Appetite Regulation , Diet, High-Fat , Energy Metabolism , Hypothalamus , Mice, Inbred C57BL , Animals , Mice , Energy Metabolism/drug effects , Hypothalamus/metabolism , Hypothalamus/drug effects , Diet, High-Fat/adverse effects , Male , Appetite Regulation/drug effects , Adipocytes/metabolism , Adipocytes/drug effects , Humans , Glucagon-Like Peptide 1/metabolism , Ghrelin/metabolism , Leptin/metabolism , Agouti-Related Protein/metabolism , Agouti-Related Protein/genetics , Thermogenesis/drug effects , Pro-Opiomelanocortin/metabolism , Pro-Opiomelanocortin/genetics , Obesity/metabolism , Obesity/physiopathology , Obesity/diet therapy , MannansABSTRACT
Due to its emulsifying and thickening properties, konjac glucomannan (KGM) is widely used in the food, medicine, and materials industries. Nevertheless, its high viscosity and significant water absorption limit its application range. Therefore, electron beam (e-beam) irradiation pretreatment was carried out to improve the deacetylation efficiency of KGM, and the physicochemical and gel properties of KGM were investigated. The results show that e-beam irradiation and deacetylation decrease the water absorption, solubility, transparency, molecular weight, and viscosity of KGM. Conversely, the moisture content, thermal stability, and water-binding capacity increase. FTIR and X-ray diffraction analysis revealed no significant changes in the chemical and crystalline structure of KGM before and after modification. However, modification weakens the intermolecular interaction of KGM hydrosols, which affects their rheology. Furthermore, deacetylation improves the mechanical properties and water retention capacity of KGM gels. Overall, the e-beam irradiation pretreatment provides a method to increase the efficiency of KGM deacetylation and improve the physical and chemical properties of KGM, thus expanding its potential applications in the food and chemical industries, among others.
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Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium, which is expected to solve the difficulty in separation and the poor selectivity of traditional photocatalysts in carbonate-containing uranium wastewater. In this paper, the γ-FeOOH/konjac glucomannan grafted with phenolic hydroxyl groups/poly-N-isopropylacrylamide (γ-FeOOH/KGM(Ga)/PNIPAM) thermosensitive hydrogel is proposed as the photocatalysts for extracting uranium from carbonate-containing uranium wastewater. The dynamic phase transformation is demonstrated to confirm the arbitrary transition of γ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel from a dispersed state with a high specific surface area at low temperatures to a stable aggregated state at high temperatures. Notably, the γ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel achieves a remarkably high rate of 92.3% in the removal of uranium from the wastewater containing carbonates and maintains the efficiency of uranium removal from uranium mine wastewater at over 90%. Relying on electron spin resonance and free radical capture experiment, we reveal the adsorption-reduction-nucleation-crystallization mechanism of uranium on γ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel. Overall, this strategy provides a promising solution to treating uranium-contaminated wastewater, showing a massive potential in water purification.
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The mechanical, barrier properties, and water resistance of packaging materials are crucial for the preservation of fruits and vegetables. In this study, zein was incorporated as a hydrophobic substance into the konjac glucomannan (KGM)/curdlan (KC) system. The KC/zein (KCZ) showed good compatibility with the zein aggregates uniformly distributed in the network formed by an entanglement of KGM and curdlan micelles based on hydrogen bonds. The presence of zein inhibited the extension of the KC entangled structure and enhanced the solid-like behavior. The high content of zein (>6 %) increased zein aggregation and negatively affected the structure and properties of KCZ. The zein addition significantly improved the water vapor permeability, tensile strength, and elongation at break. The hydrophobicity of the KCZ films was significantly enhanced, accompanied by the water contact angle increasing from 81° to 112°, and the moisture content, swelling, and soluble solid loss ratio decreasing apparently. The K56C40Z4 coating exhibited an excellent preservation effect to inhibit the respiration of cherry tomatoes, significantly reducing the water loss and firmness decline and maintaining the appearance, total solid, total acid, and ascorbic acid content. This work provided a strategy to fabricate hydrophobic packaging for the preservation of fruits and vegetables.
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This study developed a nanocomposite hydrogel, CAM4-MMT, for efficiently removing basic fuchsin dye from water. The hydrogel was prepared by grafting a copolymer of acrylic acid (AA) and acrylamide (AM) onto carboxymethyl konjac glucomannan (CMKGM), and doped with montmorillonite (MMT), exhibited excellent thermal stability, a porous inner structure, large specific surface area (1.407 m2/g), and high swelling capacity (107.3 g/g). The hydrogel achieved a maximum adsorption capacity of 694.1 mg/g and a removal rate of 99.5 %. The Langmuir isotherm and pseudo-second-order kinetic model best described the adsorption process. Regeneration and reuse tests confirmed that the hydrogel has excellent recyclability. In conclusion, the CAM4-MMT composite hydrogel efficiently removed basic fuchsin from water solutions, offering a new scheme for eliminating basic fuchsin using natural polysaccharides with promising applications.
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Due to the growing concerns surrounding microbial contamination and food safety, there has been a surge of interest in fabricating novel food packaging with highly efficient antibacterial activity. Herein, we describe novel photodynamic antibacterial konjac glucomannan (KGM)/polyvinylpyrrolidone (PVP) nanofibers incorporated with lignin-zinc oxide composite nanoparticles (L-ZnONPs) and curcumin (Cur) via electrospinning technology. The resulting KGM/PVP/Cur/L-ZnONPs nanofibers exhibited favorable hydrophobic properties (water contact angle: 118.1°), thermal stability, and flexibility (elongation at break: 241.9%). Notably, the inclusion of L-ZnONPs and Cur endowed the nanofibers with remarkable antioxidant (ABTS radical scavenging activity: 98.1%) and photodynamic antimicrobial properties, demonstrating enhanced inhibitory effect against both Staphylococcus aureus (inhibition: 12.4 mm) and Escherichia coli (12.1 mm). As a proof-of-concept study, we evaluated the feasibility of applying nanofibers to fresh strawberries, and the findings demonstrated that our nanofibers could delay strawberry spoilage and inhibit microbial growth. This photodynamic antimicrobial approach holds promise for design of highly efficient antibacterial food packaging, thereby contributing to enhanced food safety and quality assurance.
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The large molecular weight and high viscosity of natural konjac glucomannan (KGM) limit its industrial application. Microbial degradation of low-molecular-weight KGM has health benefits and various biological functions; however, the available KGM strains used in the industry have microbial contamination and low degradation efficiencies. Therefore, exploring novelly adaptable strains is critical for industrial processes. Here, the Bacillus licheniformis Z7-1 strain isolated from decaying konjac showed high efficiency for KGM degradation. The monosaccharide composition of the degradation products had a reduced molar ratio of mannose to glucose, indicating that Z7-1 preferentially degraded glucose in KGM. The degraded component was further characterized by ESI-MS, Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM), and it also exhibited good antibacterial activity against various food-spoilage bacteria. Genome sequencing and zymolytic analysis revealed that abundant carbohydrate-active enzymes exist in the Z7-1 genome, with at least five types of extracellular enzymes responsible for KGM degradation, manifesting multi-enzyme synergetic action. The extracellular enzymes had significant thermal stability, indicating their potential application in industry. This study provides an alternative method for obtaining low-molecular-weight KGM with antibacterial functions and supports foundational knowledge for its development as a biocatalyst for the direct conversion of biomass polysaccharides into functional components.
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It is still difficult for a single antibacterial modality to realize satisfactory management of bacterial breeding in food preservation. To solve this problem, we developed a photothermal-derived dual-mode synergistic bactericidal konjac glucomannan (KGM)/polycaprolactone (PCL) bilayer film incorporated with quercetin-loaded melanin-like nanoparticles (Q@MNPs). The results showed that the mechanical properties (TS: 29.8 MPa, EAB: 43.1 %), UV shielding properties, and water resistance (WCA: 124.1°, WVP: 3.92 g mm/m2 day kPa) of KGM-Q@MNPs/PCL bilayer films were significantly improved. More importantly, KGM-Q@MNPs/PCL bilayer film presented outstanding photothermal inversion and controlled release behavior of Q triggered by near infrared (NIR) radiation, thus contributing to excellent dual-mode synergistic antibacterial properties against E. coli and S. aureus. Meanwhile, the KGM-Q@MNPs/PCL bilayer film possessed good biocompatibility and low toxicity. As a proof-of-concept application, we further verified the significant value of film for the preservation of cherry tomatoes. Since KGM-Q@MNPs/PCL bilayer film showed excellent biodegradability, this work will aid the development of sustainable antibacterial food packaging materials.