Thermoplastic PHB-Reinforced Chitosan Piezoelectric Films for Biodegradable Pressure Sensors.

Flexible and wearable pressure sensors have attracted significant attention in the fields of smart medicine and human health monitoring. Nevertheless, the design and fabrication of degradable disposable pressure sensors still face urgent challenges. Herein, we fabricated poly(3-hydroxybutyrate) (PHB)-reinforced chitosan (CS) piezoelectric films for intelligent sensors through a simple, low-cost, and environmentally friendly roll-forming method. The results show that PHB doping successfully increased the effective piezoelectric coefficient of the chitosan-based film from 40.12 to 49.38 pm/V (a 23% increase). Simultaneously, the pressure sensor based on the CS/PHB film exhibited excellent response sensitivity (484 mV/kPa) and a wide linear response range (0-130 kPa), which could be used as haptic sensors and motion monitoring sensors for the fast response to human motion signals. Additionally, the CS/PHB film could be completely degraded within 18 days in a natural soil environment, demonstrating outstanding degradability. Therefore, chitosan-based piezoelectric films with excellent biodegradability and piezoelectric characteristics have been successfully fabricated in this work, which will promote the innovative development of green chitosan-based electronic devices and disposable pressure sensors.

Antibacterial evaluation of garlic extracts on chitosan/starch packaging film using response surface methodology and its application for shelf-life extension of bell peppers (Capsicum annuum).

In this study, garlic extract (GE) was assessed as a potential additive in chitosan/starch (Ch/De) coatings, focusing on phenolic and flavonoid content analyses and antibacterial properties. Using response surface methodology approach, an optimization method was employed to achieve the optimal antibacterial formulation, with Ch, De, and GE identified as key variables in the Design of Experiment. Fourier transform infrared spectroscopy and X-ray diffraction analyses elucidated interactions among these primary components within the films, while thermogravimetric analysis confirmed the enhanced thermal stability of GE-coated film formulations (Ch/De/GE). The Ch/De/GE exhibited antibacterial efficacy against Escherichia coli (ATCC 25922) with an inhibition zone of 7.2 mm at optimized concentrations of 2% w/v Ch, 1.5% w/v starch, and 0.5% v/v GE. In silico molecular docking studies provided insights into GE's inhibitory role as an antibacterial agent. Evaluation of green and yellow bell peppers (Capsicum annuum) over 18 days showed that coated peppers maintained better visual appearance and mass stability, with a weight loss decrease of 40.54%-48.96%, compared to uncoated ones. Additionally, the Ch/De/GE coating effectively inhibited bacterial growth, reducing it by 1-1.23 log CFU, during the storage period. In conclusion, the Ch/De/GE coating effectively extends the shelf-life of bell peppers and maintains their quality, demonstrating its potential for use in food packaging to preserve perishable items. PRACTICAL APPLICATION: The optimized chitosan/starch/garlic extract (Ch/De/GE) film developed in this study shows promising potential for application in the food packaging industry, particularly in extending the shelf life of perishable items like bell peppers. Its enhanced antibacterial properties, along with its ability to maintain visual appearance and reduce weight loss, make it an effective natural preservative that could replace synthetic additives in food packaging. By incorporating this biodegradable film into packaging solutions, producers can offer safer, more sustainable products that meet consumer demand for natural and environmentally friendly options.

Effect of solvent acids on the microstructure and corrosion resistance of chitosan films on MAO-treated AZ31B magnesium alloy.

This study evaluated the effect of solvent acids on the structure and corrosion resistance performance of chitosan (CS) film on MAO-treated AZ31B magnesium (Mg) alloy. Initially, CS solutions were prepared in four solvent acids: acetic acid (HAc), lactic acid (LA), hydrochloric acid (HCl), and citric acid (CA). The CS films were subsequently deposited on MAO-treated AZ31B Mg alloy via a dip-coating technique. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT-IR), contact angle measurement, and atomic force microscopy (AFM) were employed to characterize the surface and cross-sectional morphology as well as chemical composition. Furthermore, the samples were subjected to potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests to assess their resistance against corrosion in simulated body fluid (SBF). These results indicated that the CS film prepared with LA exhibited the lowest surface roughness (Ra = 31.2 nm), the largest contact angle (CA = 98.50°), and the thickest coating (36 µm). Additionally, it demonstrated superior corrosion protection performance, with the lowest corrosion current density (Icorr = 3.343 × 10-7 A/cm2), highest corrosion potential (Ecorr = -1.49 V), and highest polarization resistance (Rp = 5.914 × 104 Ω·cm2) in SBF. These results indicated that solvent acid types significantly influenced their interactions with CS. Thus, the structure and corrosion protection performance of CS films can be optimized by selecting an appropriate solvent acid.

A Novel Preservative Film with a Pleated Surface Structure and Dual Bioactivity Properties for Application in Strawberry Preservation due to Its Efficient Apoptosis of Pathogenic Fungal Cells.

Botrytis cinerea (B. cinerea) and Colletotrichum gloeosporioides (C. gloeosporioides) were isolated from the decaying strawberry tissue. The antifungal properties of Monarda didyma essential oil (MEO) and its nanoemulsion were confirmed, demonstrating complete inhibition of the pathogens at concentrations of 0.45 µL/mL (0.37 mg/mL) and 10 µL/mL, respectively. Thymol, a primary component of MEO, was determined as an antimicrobial agent with IC50 values of 34.51 (B. cinerea) and 53.40 (C. gloeosporioides) µg/mL. Hippophae rhamnoides oil (HEO) was confirmed as a potent antioxidant, leading to the development of a thymol-HEO-chitosan film designed to act as an antistaling agent. The disease index and weight loss rate can be reduced by 90 and 60%, respectively, with nutrients also being well-preserved, offering an innovative approach to preservative development. Studies on the antifungal mechanism revealed that thymol could bind to FKS1 to disrupt the cell wall, causing the collapse of mitochondrial membrane potential and a burst of reactive oxygen species.

Synthesis and Evaluation of Gelatin-Chitosan Biofilms Incorporating Zinc Oxide Nanoparticles and 5-Fluorouracil for Cancer Treatment.

In this study, a novel multifunctional biofilm was fabricated using a straightforward casting process. The biofilm comprised gelatin, chitosan, 5-fluorouracil (5-FU)-conjugated zinc oxide nanoparticles, and polyvinyl alcohol plasticized with glycerol. The 5-FU-conjugated nanoparticles were synthesized via a single-step co-precipitation process, offering a unique approach. Characterization confirmed successful drug conjugation, revealing bar-shaped nanoparticles with sizes ranging from 90 to 100 nm. Drug release kinetics followed the Korsmeyer-Peppas model, indicating controlled release behavior. Maximum swelling ratio studies of the gelatin-chitosan film showed pH-dependent characteristics, highlighting its versatility. Comprehensive analysis using SEM, FT-IR, Raman, and EDX spectra confirmed the presence of gelatin, chitosan, and 5-FU/ZnO nanoparticles within the biofilms. These biofilms exhibited non-cytotoxicity to human fibroblasts and significant anticancer activity against skin cancer cells, demonstrating their potential for biomedical applications. This versatility positions the 5-FU/ZnO-loaded sheets as promising candidates for localized topical patches in skin and oral cancer treatment, underscoring their practicality and adaptability for therapeutic applications.

An insect lac blanket-mimetic and degradable shellac hydrogel/chitosan packaging film with controllable gas permeation for fresh-cut vegetables preservation.

Fresh-cut products are extremely perishable due to the processing operations, and the atmosphere environment, especially CO2, O2 and H2O, could profoundly affect their shelf life. Herein, an insect "lac blanket"-mimetic and facile strategy was proposed for fresh-cut vegetables preservation, employing porous shellac hydrogel microparticles as gas "switches" in chitosan film to regulate CO2, O2 and H2O vapor permeability. Thus, the shellac hydrogel/chitosan hybrid film presented the controllable and wide range of gas permeability, compared with the chitosan film. The shellac-COOH nanoscale vesicles aggregated to form shellac hydrogel network via hydrophobic binding. The shellac hydrogel microparticles played a certain lubricating effect on the hybrid film casting solution. The hydrogen bond network between shellac hydrogel and chitosan contributed to the excellent mechanical properties of the hybrid film. The hybrid film also exhibited remarkable water-resistant, antifogging properties, optical transparency and degradability. The hybrid packaging films prepared through this strategy could adjust the internal gas (CO2, O2, H2O and ethylene) contents within the packages, and further exhibited admirable preservation performance on three fresh-cut vegetables with different respiratory metabolisms. This gas permeation-controlled strategy has great potential in fresh food preservation and various other applications that need a modified atmosphere.

Antimicrobial Potential of Chitosan Films Incorporated with Alcoholic Extract from Mimosa tenuiflora Leaves.

Antimicrobial films were prepared with chitosan containing the methanolic extract of M. tenuiflora leaves (FECT20%, FECT30%, and FECT40%), and their antimicrobial activities were evaluated by agar diffusion. The films were characterized by IR spectroscopy, scanning electron microscopy (SEM) and TG/DTG curves. TG/DTG curves showed thermal stability of chitosan-extract films up to 166 ºC. Micrographs of chitosan-extract films revealed an increase in porosity with the addition of extract. The FECT40% film showed inhibition zone diameters (IZ) against Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis, and B. cereus, ranging from 1.0 ± 0.02 to 0.72 ± 0.09 cm. Only FECT30% and FECT40% inhibited the P. aeruginosa with IZs of 0.68 ± 0.02 and 0.77 ± 0.06 cm, respectively. In turn, the extract showed inhibition against B. subtilis and B. cereus, with IZs values of 0.92 ± 0.2 cm and 0.72 ± 0.05 cm, respectively. Additionally, the crude extract presented antioxidant potential with inhibition percentages of 32.74% ± 0.90 for ABTS and 27.04% ± 1.36 for DPPH. The antimicrobial and antioxidant activities of the crude extract, as well as the antimicrobial property of chitosan-extract films, suggests the potential of these biopolymers for the development of wound healing bandages and new food packaging alternatives.

Effects of chitosan-based packaging film crosslinked with nanoencapsulated star anise essential oil and superchilled storage on the quality of rabbit meat patties.

In this paper, the effects of chitosan film containing star anise essential oil nanofiltration (CFSAO) and superchilled (SC) temperature on the changes of physicochemical and microbiological indexes of rabbit meat patties within 15 days of storage were studied. The total aerobic bacteria counts, malondialdehyde content, protein carbonyl content, total sulfhydryl content, and metmyoglobin content continued to grow throughout the entire experimental period, and the maximum absorption peak at the soret region of myoglobin gradually decreased. Along with the storage time extended, the brightness and redness of rabbit meat significantly decreased (P < 0.05), while the yellowness significantly increased (P < 0.05). The results of storage experiments showed that chitosan composite films and SC temperature had good inhibition on lipid oxidation, myoglobin oxidation and degradation, sulfhydryl content reduction, and microbial growth of rabbit meat after 15 days of storage, and could slow down the change of rabbit meat color.

Characterization of chitosan film incorporated pine bark extract and application in carp slices packaging.

Active films based on chitosan incorporated with pine bark extract (PBE) were prepared and characterized. Subsequently, these films were utilized for packaging carp slices in refrigerated storage at 4 ± 1 °C. Analysis of the physicochemical properties and biological activity of the active films revealed that, except for water content, all assessed indices showed an increasing trend with an increase in the amount of supplemental PBE. As this trend progresses, scanning electron microscopy (SEM) analysis revealed deposition on the film surface accompanied by transverse lines and fractures, while the color of the film gradually changed from light yellow to reddish-brown. Fourier transform infrared spectroscopy (FTIR) indicated that the phenolic hydroxyl groups in PBE interacted with the hydrogen in the amino groups of chitosan molecules to form non-covalent bonds. X-ray diffraction analysis (XRD) showed that the reaction between PBE and chitosan altered the crystalline structure of chitosan molecules. Moreover, the analysis of the effects of active films on the pH, water-holding capacity, thiobarbituric acid values, and the total bacterial counts of carp slices revealed that in terms of preservation, films containing 30 % PBE were the most effective, using which the shelf life of carp slices could be extended by 50 %.

Interfacial Dehydration Strategy for Chitosan Film Shape Morphing and Its Application.

Shape morphing of biopolymer materials, such as chitosan (CS) films, has great potential for applications in many fields. Traditionally, their responsive behavior has been induced by the differential water swelling through the preparation of multicomponent composites or cross-linking as deformation is not controllable in the absence of these processes. Here, we report an interfacial dehydration strategy to trigger the shape morphing of the monocomponent CS film without cross-linking. The release of water molecules is achieved by spraying the surface with a NaOH solution or organic solvents, which results in the interfacial shrinkage and deformation of the entire film. On the basis of this strategy, a range of CS actuators were developed, such as soft grippers, joint actuators, and a light switch. Combined with the geometry effect, edited deformation was also achieved from the planar CS film. This shape-morphing strategy is expected to enable the application of more biopolymers in a wide range of fields.

Tunable evaporation-induced surface morphologies on chitosan film for light management.

The surface morphologies of polymer films have been used to improve the performance or enable new applications of films, such as controllable adhesion, shape morphing and light management. However, complicated and destructive methods were applied to produce surface morphologies on chitosan (CS) film. To overcome this challenge, we report an evaporation-induced self-assembly to form the tunable morphologies on the surface of short-chain chitosan film by varying the evaporation rates that influence the aggregation behavior of polymer chains between order and disorder. It enables the simple, tunable and scalable fabrication of surface morphologies on CS film (CS solution concentration: 2 wt%, drying from room temperature (RT) to 80 °C) that provides controllable haze (3-74 %) and high transmittance (>85 %) for the production of hazy and transparent window coatings. This simple approach to producing tunable surface morphologies could inspire the synthesis of multifunctional polymer films with different surface structures, whose applications can be extended to cell culture interfaces, flexible bioelectronic and optoelectronic devices.

Anisotropic microtopography surface of chitosan scaffold regulating skin precursor-derived Schwann cells towards repair phenotype promotes neural regeneration.

For repairing peripheral nerve and spinal cord defects, biomaterial scaffold-based cell-therapy was emerged as an effective strategy, requiring the positive response of seed cells to biomaterial substrate and environment signals. Previous work highlighted that the imposed surface properties of scaffold could provide important guidance cues to adhered cells for polarization. However, the insufficiency of native Schwann cells and unclear cellular response mechanisms remained to be addressed. Given that, this study aimed to illuminate the micropatterned chitosan-film action on the rat skin precursor-derived Schwann cells (SKP-SCs). Chitosan-film with different ridge/groove size was fabricated and applied for the SKP-SCs induction. Results indicated that SKP-SCs cultured on 30 µm size microgroove surface showed better oriented alignment phenotype. Induced SKP-SCs presented similar genic phenotype as repair Schwann cells, increasing expression of c-Jun, neural cell adhesion molecule, and neurotrophic receptor p75. Moreover, SKP-SC-secretome was subjected to cytokine array GS67 assay, data indicated the regulation of paracrine phenotype, a panel of cytokines was verified up-regulated at secreted level and gene expression level in induced SKP-SCs. These up-regulated cytokines exhibit a series of promotive neural regeneration functions, including cell survival, cell migration, cell proliferation, angiogenesis, axon growth, and cellular organization etc. through bioinformatics analysis. Furthermore, the effectively polarized SKP-SCs-sourced secretome, promoted the proliferation and migration capacity of the primarily cultured native rat Schwann cells, and augmented neurites growth of the cultured motoneurons, as well as boosted axonal regrowth of the axotomy-injured motoneurons. Taken together, SKP-SCs obtained pro-neuroregeneration phenotype in adaptive response to the anisotropic topography surface of chitosan-film, displayed the oriented parallel growth, the transition towards repair Schwann cell genic phenotype, and the enhanced paracrine effect on neural regeneration. This study provided novel insights into the potency of anisotropic microtopography surface to Schwann-like cells phenotype regulation, that facilitating to provide promising engineered cell-scaffold in neural injury therapies.

Antimicrobial photodynamic inactivation pH-responsive films based on gelatin/chitosan incorporated with aloe-emodin.

Using novel active food packaging has gradually become a daily necessity in terms of impeding microbial contamination. Here, an antimicrobial photodynamic inactivation (PDI) pH-responsive film is developed by incorporating aloe-emodin (AE) into a vehicle of gelatin/chitosan (GC). Besides enhancement in hydrophobicity, the well-dispersed crystals of AE in the GC matrix by hydrogen bonding can upgrade the film's mechanical strength and barrier. The matrix is capable of regulating the release of AE in response to acidic stimuli by a combination mechanism of diffusion and polymer relaxation. Being benefitted from the inherent bioactivity of AE and the PDI activity under visible light irradiation (i.e., 456 nm), the target film of GC-AE2 has excellent antibacterial effect towards Staphylococcus aureus and Escherichia coli, showing bacterial viability of 9.93 ± 1.33 % and 14.85 ± 1.16 %, respectively. Furthermore, the film can effectively thwart Botrytis cinerea infection in cherry tomatoes, demonstrating its potential in preventing the microbial spoilage of postharvest fruits.

High-strength, antifogging and antibacterial ZnO/carboxymethyl starch/chitosan film with unique "Steel Wire Mesh" structure for strawberry preservation.

In this work, a multifunctional preservative film of ZnO/carboxymethyl starch/chitosan (ZnO/CMS/CS) with the unique "Steel Wire Mesh" structure is fabricated by the chemical crosslinked of ZnO NPs, CMS and CS. Unlike traditional nano-filled polymer film, the formation of the "Steel Wire Mesh" structure of ZnO/CMS/CS film is based on the synergistic effect of ZnO NPs filled CMS/CS and the coordination crosslinked between CMS/CS and Zn2+ derived from ZnO NPs. Thanks to the "Steel Wire Mesh" structure, the tensile strength and water vapor barrier of 2.5ZnO/10CMS/CS film are 2.47 and 1.73 times than that of CS film, respectively. Furthermore, the transmittance of 2.5ZnO/10CMS/CS film during antifogging test is close to 89 %, confirming its excellent antifogging effects. And the 2.5ZnO/10CMS/CS film also exhibits excellent long-acting antibacterial activity (up to 202 h), so it can maintain the freshness and appearance of strawberries at least 5 days. More importantly, the 2.5ZnO/10CMS/CS film is sensitive to humidity changes, which achieves real-time humidity monitoring of the fruit storage environment. Note that the preparation method of the film is safe, simple and environmentally friendly, and its excellent degradation performance will not bring any problems of food safety and environmental pollution.

Chitosan film with pineapple peel extract in the extension of shelf life of Indian cottage cheese: Release kinetics and bio-accessibility studies.

Pineapple-peel-based chitosan film was employed to extend the shelf life of Indian Cottage Cheese, commonly termed "paneer" in the Indian subcontinent. Pineapple peel extracts (PPE) at 3 different concentrations (1-3 %) were incorporated into the chitosan matrix. In comparison to control samples (unpacked paneer), packaged paneer samples exhibited reduced weight loss, lipid peroxidation, and pH changes. The microbiological shelf life of paneer got extended till 9th day at 4 °C when packaged in chitosan-PPE films. Korsmeyer-Peppas's model suggested that the release of polyphenols from the chitosan-PPE film followed Fickian diffusion. As per sensory evaluation on a 9-point hedonic scale, packaged paneer samples were superior in juiciness, texture, color, flavor, and overall acceptability compared to unpackaged paneer samples. As compared to the control sample (CS), the overall acceptance was higher for the film with 1 % pineapple peel extract (CS PPE 1), followed by films with 2 % and 3 % pineapple peel extracts (CS-PPE 2 and CS-PPE 3). The bio-accessibility study utilized the dynamic gastric model to simulate digestion in the upper gastrointestinal tract and revealed 40-60 % recovery rate of polyphenols from the chitosan-pineapple peel film.

Biomimetic Hydroxyapatite Crystals Growth on Phosphorylated Chitosan Films by In Vitro Mineralization Used as Dental Substitute Materials.

Chitosan (CS) films exhibit great potential as a substrate for the in vitro mineralization process. In this study, to mimic the formation of nanohydroxyapatite (HAP) as natural tissue, CS films coated with a porous calcium phosphate were investigated using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transforms infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). Calcium phosphate coating deposited on phosphorylated derivatives of CS was obtained by a process based on phosphorylation, Ca(OH)2 treatment and artificial saliva solution (ASS) immersion. The phosphorylated CS films (PCS) were obtained by partial hydrolysis of the PO4 functionalities. It was demonstrated that this precursor phase could induce the growth and the nucleation of the porous calcium phosphate coating when immersed in ASS. Moreover, oriented crystals and qualitative control of calcium phosphate phases on CS matrices are obtained in a biomimetic mode. Furthermore, in vitro antimicrobial activity of PCS was evaluated against three species of oral bacteria and fungi. It revealed an increase in antimicrobial activity with minimum inhibition concentration (MIC) values of 0.10% (Candida albicans), 0.05% (Staphylococcus aureus) and 0.025% (Escherichia coli) which proves their possible use as dental substitute materials.

Effect of neutralization treatment on properties of chitosan/bamboo leaf flavonoids/nano-metal oxide composite films and application of films in antioxidation of rapeseed oil.

Neutralization treatment improved the slow-release antioxidant food packaging function of chitosan (CS)/bamboo leaf flavone (BLF)/nano-metal oxides composite films. The film cast from the CS composite solution neutralized by KOH solution had good thermal stability. The elongation at break of the neutralized CS/BLF film was increased by about 5 times, which provided the possibility for its packaging application. After 24 h of soaking in different pH solutions, the unneutralized films swelled severely and even dissolved, while the neutralized films maintained the basic structure with a small degree of swelling, and the release trend of BLF conformed to the logistic function (R2 ≥ 0.9186). The films had a good ability to resist free radicals, which was related to the release amount of BLF and the pH of the solution. The antimicrobial neutralized CS/BLF/nano-ZnO film, like the nano-CuO and Fe3O4 films, were effective in inhibiting the increase in peroxide value and 2-thiobarbituric acid induced by thermal oxygen oxidation of rapeseed oil and had no toxicity to normal human gastric epithelial cells. Therefore, the neutralized CS/BLF/nano-ZnO film is likely to become an active food packaging material for oil-packed food, which can prolong the shelf life of packaged food.

The Adsorption Efficiency of Regenerable Chitosan-TiO2 Composite Films in Removing 2,4-Dinitrophenol from Water.

In this work, the great performance of chitosan-based films blended with TiO2 (CH/TiO2) is presented to adsorb the hazardous pollutant 2,4-dinitrophenol (DNP) from water. The DNP was successfully removed, with a high adsorption %: CH/TiO2 exhibited a maximum adsorption capacity of 900 mg/g. For pursuing the proposed aim, UV-Vis spectroscopy was considered a powerful tool for monitoring the presence of DNP in purposely contaminated water. Swelling measurements were employed to infer more information about the interactions between chitosan and DNP, demonstrating the presence of electrostatic forces, deeply investigated by performing adsorption measurements by changing DNP solutions' ionic strength and pH values. The thermodynamics, adsorption isotherms, and kinetics were also studied, suggesting the DNP adsorption's heterogeneous character onto chitosan films. The applicability of pseudo-first- and pseudo-second-order kinetic equations confirmed the finding, further detailed by the Weber-Morris model. Finally, the adsorbent regeneration was exploited, and the possibility of inducing DNP desorption was investigated. For this purpose, suitable experiments were conducted using a saline solution that induced the DNP release, favoring the adsorbent reuse. In particular, 10 adsorption/desorption cycles were performed, evidencing the great ability of this material that does not lose its efficiency. As an alternative approach, the pollutant photodegradation by using Advanced Oxidation Processes, allowed by the presence of TiO2, was preliminary investigated, opening a novel horizon in the use of chitosan-based materials for environmental applications.

Chitosan Based Biodegradable Composite for Antibacterial Food Packaging Application.

A recent focus on the development of biobased polymer packaging films has come about in response to the environmental hazards caused by petroleum-based, nonbiodegradable packaging materials. Among biopolymers, chitosan is one of the most popular due to its biocompatibility, biodegradability, antibacterial properties, and ease of use. Due to its ability to inhibit gram-negative and gram-positive bacteria, yeast, and foodborne filamentous fungi, chitosan is a suitable biopolymer for developing food packaging. However, more than the chitosan is required for active packaging. In this review, we summarize chitosan composites which show active packaging and improves food storage condition and extends its shelf life. Active compounds such as essential oils and phenolic compounds with chitosan are reviewed. Moreover, composites with polysaccharides and various nanoparticles are also summarized. This review provides valuable information for selecting a composite that enhances shelf life and other functional qualities when embedding chitosan. Furthermore, this report will provide directions for the development of novel biodegradable food packaging materials.

Evaluation of antioxidant films of chitosan with Aquilaria agallocha extract as packaging material.

In this study, the bark of the Aquilaria agallocha was extracted, and the phenolic content of A. agallocha extract was determined using high-performance liquid chromatography-diode array detector. The A. agallocha extract-chitosan edible films were prepared by using a different amount of A. agallocha extract (0, 1, 4, and 8 mL) and chitosan solution. Some physical properties of A. agallocha extract-chitosan edible films, water vapor permeability, solubility, swelling ratio, humidity ratio, thickness, scanning electron microscopy, and Fourier transform infrared spectroscopy analysis were investigated. The antibacterial activities, total phenolic content, and antioxidant capacity analysis of the A. agallocha extract-chitosan edible films were performed. The total phenolic content (0, 1, 4, and 8 mL of A. agallocha extract-chitosan edible films 0.92 ± 0.09, 1.34 ± 0.04, 2.94 ± 0.10, and 4.62 ± 0.10 mg gallic acid equivalent (GAE)/g film, respectively) and antioxidant capacity (0, 1, 4, and 8 mL of A. agallocha extract-chitosan edible films 52.61 ± 2.85, 104.28 ± 4.78, 304.30 ± 18.23, and 592.11 ± 0.67 mg Trolox equivalent (TE)/g film, respectively) of A. agallocha extract-chitosan edible films increased with the increase in the amount of extract. At the same time, the increase in the amount of antioxidant capacity improved the physical features of the films. The results of the antibacterial activity studies showed that all of the A. agallocha extract-chitosan edible films prevented bacterial growth from Escherichia coli and Staphylococcus aureus considering controlling group. PRACTICAL APPLICATIONS: To investigate the activity of antioxidant extract-biodegradable film, the A. agallocha extract-chitosan edible film had prepared. The results showed that A. agallocha extract-chitosan edible film was antioxidant and antibacterial properties and was used as food packaging material successfully.