Effect of Kaolin clay and Ficus carica mediated silver nanoparticles on chitosan food packaging film for fresh apple slice preservation

Preparation of amphiphilic polyquaternium nanofiber films with antibacterial activity via environmentally friendly microfluidic-blow-spinning for green food packaging applications

Green food packaging plays an important role in environmental protection and sustainable development. Therefore, it is advisable to employ low-energy consumption manufacturing techniques, select environmentally friendly materials, and focus on cost-effectiveness with high production yields during the production process. In this study, an amphiphilic polyquaternium called PBzCl was proposed and synthesized by free radical polymerization of cost-efficient quaternary ammonium salts and methacrylate monomers. Then, biodegradable PCL and PVP were used to rapidly prepare the PBzCl@PCL/PVP nanofiber films via environmentally friendly microfluidic-blow-spinning (MBS). The best antibacterial effect was observed at a PBzCl loading concentration of 13.5%, and the PBzCl@PCL/PVP nanofiber films had 91% and 100% antibacterial rates against Escherichia coli and Staphylococcus aureus, respectively. Besides, the loading of PBzCl improved the water stability of the PCL/PVP nanofiber films, and the films also showed excellent biocompatibility. Overall, PBzCl@PCL/PVP nanofibre films have promising food packaging potential.

Properties of modified chitosan-based films and coatings and their application in the preservation of edible mushrooms: A review

Edible mushrooms are prone to deteriorate during storage. A Single chitosan film or coating has limitations in preservation. Therefore, this article focused on the improvement of modified chitosan-based films and coatings on properties related to storage quality of edible mushrooms (e.g.: safety, barrier, mechanical, antioxidant and antibacterial properties). Besides, the application of chitosan-based materials in the preservation of mushrooms was also discussed. The modified chitosan film and coating can slow down the respiration of mushrooms, inhibit the growth of microorganisms, protect antioxidant compositions, and regulate the activity of related enzymes, thus improving the quality and prolonging the shelf life of mushrooms. Meanwhile, the added ingredients improve the water and gas barrier properties of chitosan through volume and group occupation, and reduce the light transmittance of chitosan through light transmission, scattering and absorption. Essential oils and polyphenolic compounds had a better enhancement of antioxidant and antimicrobial properties of chitosan.

Enhancing Fresh-Cut Apple Preservation: Impact of Slightly Acidic Electrolyzed Water and Chitosan-Apple Essence Microencapsulation Coating on Browning and Flavor

Fresh-cut apple preservation is a critical concern in the food industry due to the rapid deterioration of texture, color, and flavor. While our previous study introduced apple essence microencapsulation (AEM) to enhance flavor during storage, its impact on overall storage quality was minimal. Thus, this study explores the application of two preservation techniques, namely, slightly acidic electrolyzed water (SAEW) and chitosan-apple essence microencapsulation (CH-AEM) coating, to enhance the quality of fresh-cut apples. Our findings reveal that SAEW treatment significantly reduces the browning index (from 65.38 to 57.36) and respiratory rate (from 5.10% to 4.30% of CO2), and maintains a desirable aroma profile compared to uncoated treatment during 10 days of storage. Additionally, the CH-AEM coating acts as a protective barrier, further preserving the sensory characteristics of fresh-cut apples. Notably, the SAEW-CH-AEM group exhibits superior performance in firmness (8.14 N), respiratory rate (3.37% of CO2), ion leakage (34.86%), and juice yield (47.52%) after 10 days. Our research highlights the synergistic effect of combining these preservation strategies, providing a promising approach for extending the shelf life of fresh-cut apples while maintaining their visual appeal and aromatic quality. These results offer valuable insights for the fresh-cut produce industry, contributing to improved apple product preservation and consumer satisfaction.

Humidity-adjustable functional gelatin hydrogel/ethyl cellulose bilayer films for active food packaging application

A sustainable functional bilayer film composed of gelatin hydrogel/ethyl cellulose was fabricated using a simple LBL casting method. The outer layer was hydrophobic ethyl cellulose (EC), while the inner layer was hydrophilic gelatin (GEL) hydrogel. Tannic acid (TA) served as a green cross-linker for GEL hydrogel preparation and as a reductant for AgNPs synthesis in-situ within the hydrogel network. Physicochemical and functional properties of the bilayer films containing different TA content were studied. When 3 wt% TA was added, the AgNPs@GT-3/EC bilayer film exhibited superior UV-light barrier, possessed desirable humidity-adjustable capability and oxygen barrier due to denser hydrogel network structure, and effectively inactivated foodborne pathogens S. aureus and E. coli with bacteriostatic rates of 99 %. The application results indicated that this bilayer film effectively maintained the postharvest quality of white button mushrooms and prolonged their shelf-life to 7 days under ambient storage, demonstrating its promising potential for fresh food packaging.

Sodium alginate/guar gum based nanocomposite film incorporating β-Cyclodextrin/persimmon pectin-stabilized baobab seed oil Pickering emulsion for mushroom preservation

The poor biological, mechanical and water-resistance properties of sodium alginate/guar gum film (SG) limit its application in food preservation. To overcome this disadvantage, we added β-Cyclodextrin/persimmon pectin-stabilized baobab seed oil Pickering emulsion (BOPE) to enhance the mechanical and water resistance properties of SG film, and added green synthesized silver nanoparticles (AgNPS) and Lycium ruthenicum extract (LA) to improve the biological properties of the film. The properties of BOPE was optimized using Box-Behnken design (BBD). Scanning electron microscope and Fourier transform infrared results revealed the change of structure and molecular interaction in the SG film after the addition of AgNPS, LA, and optimized BOPE. The 2.0%BOPE-loaded film containing AgNPS/LA with the enhanced mechanical, barrier, BO retention, and biological properties not only improved the preservation effect on mushroom (A. bisporus), but also maintained structural stability. Thus, the 2.0%BOPE-loaded SG/LA/AgNPS film has considerable potential in active packaging applications.

High transparency, water vapor barrier and antibacterial properties of chitosan/carboxymethyl glucan/poly(vinyl alcohol)/nanoparticles encapsulating citral composite film for fruit packaging

Utilizing antibacterial packaging material is an effective approach to delay fruit rotting and spoilage thereby minimizing financial losses and reducing health harm. However, the barrier and mechanical properties of biodegradable antibacterial packaging materials are barely compatible with transparency. Herein, antimicrobial nanoparticles encapsulating citral (ANPs) were first prepared by emulsification under the stabilization of oxidized dextran (ODE) and ethylene diamine. Then, composite films with high transparency, good water vapor barrier, and mechanical and antibacterial properties for fruits packaging were prepared from chitosan (CS), carboxymethyl-glucan (CMG), poly(vinyl alcohol) (PVA), and ANPs by solvent casting strategy. The synergistic effects of electrostatic interaction and hydrogen bonding could regulate crystalline architecture, generating high transparency of the composite films (90 %). The mechanical properties of the composite film are improved with elongation at break up to 167 % and stress up to 32 MPa. The water vapor barrier property of the film is appropriate to the packed fruit for less weight loss and firmness remaining. Simultaneously, the addition of ANPs endowed the film with excellent antimicrobial and UV-barrier capabilities to reduce fruit mildew, thereby extending the shelf life of fruits. More importantly, the composite polymer solution could be sprayed or dipped directly on fruits as a coating for food storage to improve food shelf life, substantially expanding its ease of use and scope of use.

Metal nanoparticles and carbohydrate polymers team up to improve biomedical outcomes

The convergence of carbohydrate polymers and metal nanoparticles (MNPs) holds great promise for biomedical applications. Researchers aim to exploit the capability of carbohydrate matrices to modulate the physicochemical properties of MNPs, promote their therapeutic efficiency, improve targeted drug delivery, and enhance their biocompatibility. Therefore, understanding various attributes of both carbohydrates and MNPs is the key to harnessing them for biomedical applications. The many distinct types of carbohydrate-MNP systems confer unique capabilities for drug delivery, wound healing, tissue engineering, cancer treatment, and even food packaging. Here, we introduce distinct physicochemical/biological properties of carbohydrates and MNPs, and discuss their potentials and shortcomings (alone and in combination) for biomedical applications. We then offer an overview on carbohydrate-MNP systems and how they can be utilized to improve biomedical outcomes. Last but not least, future perspectives toward the application of such systems are highlighted.

Production of PVA-chitosan films using green synthesized ZnO NPs enriched with dragon fruit extract envisaging food packaging applications

In this work, the PVA-chitosan composite packaging films doped with biomass-fabricated zinc oxide nanoparticles (ZnO NPs) and dragon fruit waste extract (DFE) were developed for potential use in food packaging applications. ZnO NPs were synthesized using a sustainable method employing C. sinensis waste extract as a reducing agent. Chitosan and PVA were blended in a specific ratio (1: 1 w/w) to obtain a film-forming solution, into which the ZnO NPs and dragon fruit waste extract were incorporated. The resulting solution was cast into films, which were characterized using various analytical techniques. Mechanical properties, water solubility, and thermal stability of the films were also evaluated. The results demonstrated that the incorporation of green ZnO NPs and dragon fruit waste extract enhanced the mechanical strength and thermal stability of the films while reducing water vapor permeability. Moreover, the films exhibited biocidal and excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging properties, indicating their use in the food packaging sector. The production of these films offers a practical approach to produce bioactive food packaging materials. The use of plant extract and waste material as reducing agents can reduce the overall cost of production while providing added benefits, such as antioxidant and antibacterial properties.

Chitosan-grafted phenolic acids as an efficient biopolymer for food packaging films/coatings

Chitosan (CS), a bio-renewable natural material, has the potential to be utilized as a biopolymer for food packaging films (PFs)/coatings. However, its low solubility in dilute acid solutions and poor antioxidant and antimicrobial activities limit its application in PFs/coatings. To address these restrictions, chemical modification of CS has garnered increasing interest, with graft copolymerization being the most extensively used method. Phenolic acids (PAs) as natural small molecules are used as excellent candidates for CS grafting. This work focuses on the progress of CS grafted PA (CS-g-PA) based films, introducing the chemistry and methods of preparing CS-g-PA, particularly the effects of different PAs grafting on the properties of CS films. In addition, this work discusses the application of different CS-g-PA functionalized PFs/coatings for food preservation. It is concluded that the food preservation capability of CS-based films/coatings can be improved by modifying the properties of CS-based films through PA grafting.

Preparation and Characterization of a Biodegradable Film Using Irradiated Chitosan Incorporated with Lysozyme and Carrageenan and Its Application in Crayfish Preservation

In this study, a composite film was prepared using irradiated chitosan, lysozyme, and carrageenan for crayfish preservation. First, the chitosan was degraded by gamma rays, with the best antimicrobial properties being found at 100 KGy. By using the response surface method, the components of the composite film were irradiated chitosan (CS) at 0.016 g/mL, lysozyme (LM) at 0.0015 g/mL, and carrageenan (CA) at 0.002 g/mL. When compared to the natural chitosan film, the Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results demonstrated that the chemical properties of the composite film did not change with the addition of LM and CA, while the physical and antibacterial properties increased, including tensile strength (16.87 → 20.28 N), hydrophobicity (67.9 → 86.3°), and oxygen permeability (31.66 → 24.31 m³·um/m²·day·kPa). Moreover, the antibacterial activity of the films increased with the addition of LM and CA, especially for Shewanella putrefaciens: the zone of inhibition (mm) of CS, CS/LM, and CS/LM/CA was 9.97 ± 0.29, 14.32 ± 0.31, and 14.78 ± 0.21, respectively. Finally, the CS/LM/CA film could preserve crayfish for 10 days at 4 °C, whereas the polyethylene (PE) film could only preserve them for 6 days. Moreover, the composite film was excellent at inhibiting oxidative deterioration (TBARS value: 2.12 mg/kg, day10) and keeping the texture of crayfish muscle. Overall, our results suggested that the CS/LM/CA composite film produced can be applied as a biodegradable film in aquatic product packaging.

Chitosan/kaolinite clay biocomposite as a sustainable and environmentally eco-friendly coating material for slow release NPK fertilizers: Effect on soil nutrients and tomato growth

Soil nutrient availability and non-biodegradation of some polymer-based slow-release fertilizers (SRFs) have a direct impact on crop production and soil ecological quality. Proper fertilization practices can lead to obviating adverse effects of over-fertilization on soil nutrients and, consequently, on crop yields. This work aims to assess the effect of a durable liner material based on biodegradable polymers on soil nutrient availability and tomato growth. For this purpose, Chitosan composite (CsGC) was adopted as a durable coating material, including clay as a reinforcing coating material. The influence of chitosan composite coating (CsGC) on the sustained nutrient release of coated NPK fertilizer (NPK/CsGC) was studied. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX) were used to examine the coated NPK granules. Results revealed that the proposed coating film improved the mechanical strength of the NPK fertilizer and enhanced water retention capacity of the soil. The agronomic investigation has also proved their outstanding potential to boost chlorophyll content, biomass, and tomato metabolism. Furthermore, the surface response study confirmed a strong correlation between tomato quality and representative soil nutrients. Therefore, kaolinite clay, as part of the coating system, can be an effective way to improve tomato quality and maintain soil nutrients during tomato ripening.

Biosynthesis and Characterization of Silver Nanoparticles Using Tribulus terrestris Seeds: Revealed Promising Antidiabetic Potentials

Green synthesis is the most effective and environmentally friendly way to produce nanoparticles. The present research aimed at the biosynthesizing of silver nanoparticles (AgNPs) using Tribulus terrestris seed extract as the reducing and stabilizing agent and investigating their anti-diabetic properties. Fourier transformation infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy were used to analyze the synthesized silver nanoparticles from Tribulus terrestris (TT-AgNPs). The spectroscopic characterization revealed a surface Plasmon resonance band at 380 nm, which verified the development of TT-AgNPs. The transmittance peaks were observed at 596, 1450, 1631, 2856, 2921, and 3422 cm^-1 through the FTIR spectrophotometer. The XRD spectrum showed four distinct diffraction peaks in the 2θ range at 20° to 60°. Intense peaks were at 26.32°, 30.70°, 44.70°, 56.07°, 53.75°, 66.28°, and 75.32°. The SEM analysis revealed that the prepared TT-AgNPs were clustered loosely with a smooth and spherical structure and were of relatively uniform size. The in vitro antidiabetic potential of TT-AgNPs was assessed by using glucose yeast uptake, glucose adsorption, and alpha-amylase assays. TT-AgNPs showed the highest activity (78.45 ± 0.84%) of glucose uptake by yeast at 80 µg/mL. In the glucose adsorption assay, the highest activity of TT-AgNPs was 10.40 ± 0.52% at 30 mM, while in the alpha-amylase assay, TT-AgNPs exhibited the maximum activity of 75.68 ± 0.11% at 100 µg/mL. The results indicate a substantial anti-diabetic effect of the TT-AgNPs. Furthermore, the in vivo antidiabetic study was performed on TT-AgNPs in streptozotocin-induced diabetic mice. After receiving TT-AgNPs treatment for 30 days, the mice were sacrificed for biochemical and histological analyses of pancreatic and liver samples, which demonstrated a good improvement when compared to the control group. Mice treated with TT-AgNPs showed a significant drop in blood sugar levels, showing that the biosynthesized TT-AgNPs have effective anti-diabetic properties.

Effects of grape seed extract on the properties of pullulan polysaccharide/xanthan gum active films for apple preservation

Grape seed extract (GSE) was added to pullulan polysaccharide (PP)/xanthan gum (XG) as composite film (PP/XG/GSE or PXG). The observed composite morphology indicated their biocompatibility. Sample PXG100 (contain 100 mg/L GSE) demonstrated the best mechanical properties, with tensile strength of 16.62 ± 1.27 MPa, and the elongation at break of (22.60 ± 0.48)%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity of PXG150 were the highest at (81.52 ± 1.57)% and (90.85 ± 1.54)%, respectively. PXG films also demonstrated inhibitory effects on Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The PXG films could also prolong the shelf life of fresh-cut apples because it could decrease the rate of weight loss and retain more vitamin C and total polyphenol even on the 5th day. The weight loss rate of PXG150 was decreased from (8.58 ± 0.6)% (control) to (4.15 ± 0.19)%. It was able to achieve vitamin C and total polyphenol retention rate of 91 % and 72 %, respectively, which was significantly higher that the control sample. Therefore, GSE had contributed in enhancing the antibacterial, antioxidant properties, mechanical strength, UV protection and water resistance in PXG composite films. This effectively extend the shelf life of fresh-cut apples, which it will be an excellent food packaging material.

Triple-function chitosan-based film for pork and shrimp packaging

A film simultaneously with colorimetric, fluorescent and active functions was engineered using chitosan (CS) and polyvinyl alcohol (PVA) as the film matrix and curcumin-β-cyclodextrin complex (Cur-β-CD) as the indicator for freshness monitoring and maintaining of pork and shrimp. In addition to the efficacy of prolonging shelf life, the film's color could change from yellow to orange with ΔE > 5 and its fluorescence intensity could decrease during storage. The incorporation of PVA significantly enhanced the mechanical properties of CS film with tensile strength of 31.80 MPa and elongation at break of 127.22 %. The Cur-β-CD improved the antioxidant and antibacterial properties, water contact angle (from 86.3° to 111.2°), water vapor permeability (from 3.28 × 10^-10 g (m s Pa)^-1 to 0.42 × 10^-10 g (m s Pa)^-1) and mechanical properties of CS/PVA film. These results show the potential of the film as promising alternatives for intelligent and active food packaging.