A novel solution blending method for using olive oil and corn oil as plasticizers in chitosan based organoclay nanocomposites

Chitosan-metal and metal oxide nanocomposites for active and intelligent food packaging; a comprehensive review of emerging trends and associated challenges

In recent years, significant advancements in biopolymer-based packaging have emerged as a response to the environmental challenges posed by traditional petroleum-based materials. The drive for sustainable, renewable, and degradable alternatives to fossil-based components in the packaging industry has led to an increased focus on chitosan, the second most abundant biopolymer after cellulose. Chitosan offers intrinsic properties such as biodegradability, biocompatibility, antimicrobial activity, excellent barrier and film-forming capabilities, positioning it as an ideal candidate for food packaging applications. However, limitations including inferior mechanical, thermal, barrier properties, and brittleness compared to conventional plastics have limiting its widespread adoption in the food packaging industry. Chitosan has been extensively utilized in various forms, particularly as nanocomposites incorporating metal nanoparticles, leading to chitosan-based nanocomposite films/coatings that synergistically combine the advantageous properties of both chitosan and metal nanoparticles. Through an in-depth analysis of the current research (primarily the last 5 years), this review delves into the physicochemical, mechanical, sensing, and antimicrobial properties of chitosan nanocomposite as an innovative food packaging material. This review will provide insights into the potential toxicity and environmental impact of nanoparticle migration, as well as the prospects and challenges associated with chitosan-metal/metal oxide nanocomposite films in the development of sustainable packaging solutions.

Properties and application of antioxidant and antibacterial composite films based on methylcellulose and spine grape pomace fabricated by thermos-compression molding

Methylcellulose (MC)/grape pomace (GP) films, plasticized with either glycerol (GLY) or cinnamon essential oil (CEO), were prepared by thermo-compression molding and characterized. Compared to the GLY-plasticized MC50/GP50 films, a considerable increase in TS and YM values of CEO-plasticized films was observed, rising from 9.66 to 30.05 MPa, 762 to 1631 MPa, respectively. Moreover, the water vapor barrier, surface hydrophobic properties, and antioxidant/antibacterial activities of CEO-plasticized films remarkedly improved with increasing CEO content from 5 to 15% w/w. From scanning electron microscopy, phase separation between GP and the MC/GLY mixture were evident for GLY-plasticized MC/GP films. On the other hand, the CEO-plasticized films showed compact morphologies, attributable to the formation of hydrogen bonding and π-π stacking interaction. Preliminary shelf-life study on showed that fresh chicken wrapped with the CEO-plasticized MC/GP films exhibited lower TVB-N, TBARS, and TVC values than the unwrapped control samples, during 7 d storage at 4 °C.

A Novel Magnetic β-Cyclodextrin-Modified Graphene Oxide and Chitosan Composite as an Adsorbent for Trace Extraction of Four Bisphenol Pollutants from Environmental Water Samples and Food Samples

In this study, a novel functionalized magnetic composite (MNCGC) for magnetic solid-phase extraction of bisphenols from environmental and food samples was developed, featuring a multistep synthesis with Fe3O4, chitosan, graphene oxide, and β-cyclodextrin, crosslinked by glutaraldehyde. Characterization confirmed its advantageous morphology, intact crystal structure of the magnetic core, specific surface area, and magnetization, enabling efficient adsorption and separation via an external magnetic field. The optimized MSPE-HPLC-FLD method demonstrated excellent sensitivity, linearity, and recovery rates exceeding 80% for bisphenol pollutants, validating the method's effectiveness in enriching and detecting trace levels of bisphenols in complex matrices. This approach offers a new avenue for analyzing multiple bisphenol residues, with successful application to environmental water and food samples, showing high recovery rates.

A Review of the Effect of Plasticizers on the Physical and Mechanical Properties of Alginate-Based Films

In recent years, there has been a growing attempt to manipulate various properties of biodegradable materials to use them as alternatives to their synthetic plastic counterparts. Alginate is a polysaccharide extracted from seaweed or soil bacteria that is considered one of the most promising materials for numerous applications. However, alginate potential for various applications is relatively limited due to brittleness, poor mechanical properties, scaling-up difficulties, and high water vapor permeability (WVP). Choosing an appropriate plasticizer can alleviate the situation by providing higher flexibility, workability, processability, and in some cases, higher hydrophobicity. This review paper discusses the main results and developments regarding the effects of various plasticizers on the properties of alginate-based films during the last decades. The plasticizers used for plasticizing alginate were classified into different categories, and their behavior under different concentrations and conditions was studied. Moreover, the drawback effects of plasticizers on the mechanical properties and WVP of the films are discussed. Finally, the role of plasticizers in the improved processing of alginate and the lack of knowledge on some aspects of plasticized alginate films is clarified, and accordingly, some recommendations for more classical studies of the plasticized alginate films in the future are offered.

Chitosan with Natural Additives as a Potential Food Packaging

Recently, the development of materials based on natural polymers have been observed. This is the result of increasing environmental degradation, as well as increased awareness and consumer expectations. Many industries, especially the packaging industry, face challenges resulting from legal regulations. Chitin is the most common biopolymer right after cellulose and is used to produce chitosan. Due to the properties of chitosan, such as non-toxicity, biocompatibility, as well as antimicrobial properties, chitosan-based materials are used in many industries. Many studies have been conducted to determine the suitability of chitosan materials as food packaging, and their advantages and limitations have been identified. Thanks to the possibility of modifying the chitosan matrix by using natural additives, it is possible to strengthen the antioxidant and antimicrobial activity of chitosan films, which means that, in the near future, chitosan-based materials will be a more environmentally friendly alternative to the plastic packaging used so far. The article presents literature data on the most commonly used natural additives, such as essential oils, plant extracts, or polysaccharides, and their effects on antimicrobial, antioxidant, mechanical, barrier, and optical properties. The application of chitosan as a natural biopolymer in food packaging extends the shelf-life of various food products while simultaneously reducing the use of synthetic plastics, which in turn will have a positive impact on the natural environment. However, further research on chitosan and its combinations with various materials is still needed to extent the application of chitosan in food packaging and bring its application to industrial levels.

Nanocomposite Film Development Based on Chitosan/Polyvinyl Alcohol Using ZnO@montmorillonite and ZnO@Halloysite Hybrid Nanostructures for Active Food Packaging Applications

The global turn from the linear to the circular economy imposes changes in common activities such as food packaging. The use of biodegradable materials such as polyvinyl alcohol, natural raw materials such as clays, and food byproducts such as chitosan to develop novel food packaging films attracts the interest of industrial and institutional research centers. In this study, novel hybrid nanostructures were synthesized via the growth of zinc oxide nanorods on the surface of two nanoclays. The obtained nanostructures were incorporated with chitosan/polyvinyl alcohol composite either as nanoreinforcement or as an active agent to develop packaging films. The developed films were characterized via XRD, FTIR, mechanical, water-vapor diffusion, water sorption, and oxygen permeability measurements. Antimicrobial activity measurements were carried out against four different pathogen microorganisms. XRD indicated the formation of an intercalated nanocomposite structure for both types of nanoclays. Furthermore, improved tensile, water/oxygen barrier, and antimicrobial properties were recorded for all films compared to the pure chitosan/polyvinyl alcohol film. Overall, the results indicated that the use of the bio-based developed films led to an extension of food shelf life and could be used as novel active food packaging materials. Among them, the most promising film was the 6% wt. ZnO@halloysite.

Strategies to Improve the Barrier and Mechanical Properties of Pectin Films for Food Packaging: Comparing Nanocomposites with Bilayers

Traditional food packaging systems help reduce food wastage, but they also produce environmental impacts when not properly disposed of. Bio-based polymers are a promising solution to overcome these impacts, but they have poor barrier and mechanical properties. This work evaluates two strategies to improve these properties in pectin films: the incorporation of cellulose nanocrystals (CNC) or sodium montmorillonite (MMT) nanoparticles, and an additional layer of chitosan (i.e., a bilayer film). The bionanocomposites and bilayer films were characterized in terms of optical, morphological, hygroscopic, mechanical and barrier properties. The inclusion of the nanofillers in the polymer reduced the water vapor permeability and the hydrophilicity of the films without compromising their visual properties (i.e., their transparency). However, the nanoparticles did not substantially improve the mechanical properties of the bionanocomposites. Regarding the bilayer films, FTIR and contact angle studies revealed no surface and/or chemical modifications, confirming only physical coating/lamination between the two polymers. These bilayer films exhibited a dense homogenous structure, with intermediate optical and hygroscopic properties. An additional layer of chitosan did not improve the mechanical, water vapor and oxygen barrier properties of the pectin films. However, this additional layer made the material more hydrophobic, which may play an important role in the application of pectin as a food packaging material.

Effect of Copper and Titanium-Exchanged Montmorillonite Nanostructures on the Packaging Performance of Chitosan/Poly-Vinyl-Alcohol-Based Active Packaging Nanocomposite Films

In this study, CuMt and TiMt montmorillonites were produced via an ion-exchange process with Cu⁺ and Ti⁴⁺ ions. These nanostructured materials were characterized with X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) measurements and added as nanoreinforcements and active agents in chitosan (CS)/poly-vinyl-alcohol (PVOH)-based packaging films. The developed films were characterized by XRD and FTIR measurements. The antimicrobial, tensile, and oxygen/water-barrier measurements for the evaluation of the packaging performance were carried out to the obtained CS/PVOH/CuMt and CS/PVOH/TiMt films. The results of this study indicated that CS/PVOH/CuMt film is a stronger intercalated nanocomposite structure compared to the CS/PVOH/TiMt film. This fact reflected higher tensile strength and water/oxygen-barrier properties. The antibacterial activity of these films was tested against four food pathogenic bacteria: Escherichia coli, Staphylococcus aureus, Salmonella enterica and Listeria monocytogenes. Results showed that in most cases, the antibacterial activity was generated by the CuMt and TiMt nanostructures. Thus, both CS/PVOH/CuMt and CS/PVOH/TiMt films are nanocomposite candidates with very good perspectives for future applications on food edible active packaging.

Chitosan as a Valuable Biomolecule from Seafood Industry Waste in the Design of Green Food Packaging

Chitosan is a versatile biomolecule with a broad range of applications in food and pharmaceutical products. It can be obtained by the alkaline deacetylation of chitin. This biomolecule can be extracted using conventional or green methods from seafood industry residues, e.g., shrimp shells. Chitin has limited applications because of its low solubility in organic solvents. Chitosan is soluble in acidified solutions allowing its application in the food industry. Furthermore, biological properties, such as antioxidant, antimicrobial, as well as its biodegradability, biocompatibility and nontoxicity have contributed to its increasing application as active food packaging. Nevertheless, some physical and mechanical features have limited a broader range of applications of chitosan-based films. Green approaches may be used to address these limitations, leading to well-designed chitosan-based food packaging, by employing principles of a circular and sustainable economy. In this review, we summarize the properties of chitosan and present a novel green technology as an alternative to conventional chitin extraction and to design environmentally friendly food packaging based on chitosan.

Development of Poly(L-Lactic Acid)/Chitosan/Basil Oil Active Packaging Films via a Melt-Extrusion Process Using Novel Chitosan/Basil Oil Blends

Following the global trend toward a cyclic economy, the development of a fully biodegradable active packaging film is the target of this work. An innovative process to improve the mechanical, antioxidant, and barrier properties of Poly(L-Lactic Acid)/Chitosan films is presented using essential basil oil extract. A Chitosan/Basil oil blend was prepared via a green evaporation/adsorption method as a precursor for the development of the Poly(L-Lactic Acid)/Chitosan/Basil Oil active packaging film. This Chitosan/Basil Oil blend was incorporated directly in the Poly(L-Lactic Acid) matrix with various concentrations. Modification of the chitosan with the Basil Oil improves the blending with the Poly(L-Lactic Acid) matrix via a melt-extrusion process. The obtained Poly(L-Lactic Acid)/Chitosan/Basil Oil composite films exhibited advanced food packaging properties compared to those of the Poly(L-Lactic Acid)/Chitosan films without Basil Oil addition. The films with 5%wt and 10%wt Chitosan/Basil Oil loadings exhibited better thermal, mechanical, and barrier behavior and significant antioxidant activity. Thus, PLLA/CS/BO5 and PLLA/CS/BO10 are the most promising films to potentially be used for active packaging applications.

Developing multicomponent edible films based on chitosan, hybrid of essential oils, and nanofibers: Study on physicochemical and antibacterial properties

Plastic waste is one of the major threats to the environment, and an urgent need to replace synthetic plastics with sustainable materials is progressively growing. Herein, sustainable films based on chitosan, Satureja, and Thyme essential oils (EOs), and chitosan nanofibers (NF) were developed for the first time. To this end, 1% (w/w) of EOs and 2 wt% of NF were incorporated into the chitosan solution. Despite the very similar chemical structure of carvacrol and thymol, which are the major constituents of Satureja and Thyme EOs, respectively, they imposed notably different effects on the physicochemical properties of chitosan films. Thyme EO was more efficient at establishing hydrogen bonds with chitosan. The disruptive effect of EOs on the crystalline network of chitosan was demonstrated through X-ray diffraction analysis. Satureja and Thyme EOs decreased and increased the barrier property of the chitosan films against water vapor, respectively. However, the barrier property was greatly improved in the presence of chitosan nanofibers. Satureja EO exhibited a more efficient antibacterial property against E. coli rather than Thyme EO. The fruits and vegetables, coated by the chitosan/EO/NF system, were less perished as compared with the control and chitosan-coated samples indicating the promising potential of the developed system to be used as edible and sustainable films and coatings due to their enhanced antibacterial and barrier properties.

Fabrication and Adsorption Optimization of Novel Magnetic Core-shell Chitosan/Graphene Oxide/β-cyclodextrin Composite Materials for Bisphenols in Aqueous Solutions

A novel magnetic composite material, Fe3O4@SiO2/chitosan/graphene oxide/β-cyclodextrin (MCGC), was prepared by multi-step methods. Various methods were used to systematically characterize the morphology, composition, structure, and magnetic properties of MCGC. The results obtained show that the composite material has good morphology and crystal structure and can be separated quickly by an external magnetic field. The operation is relatively easy, and the raw materials used to prepare this material are economical, easy to obtain, and environmentally friendly. The performance and adsorption mechanism for using this material as an adsorbent to remove bisphenol A (BPA) and bisphenol F (BPF) from water were studied. The adsorption parameters were optimized. Under optimal conditions, MCGC was found to remove more than 90% of BPA and BPF in a mixed solution (20 mg/L, 50 mL); the adsorption process for BPA and BPF on MCGC was found to follow a Redlich-Peterson isotherm model and Pseudo-second-order kinetic model. The adsorption mechanism for MCGC may involve a combination of various forces. Recycling experiments showed that after five uses, MCGC retained a more than 80% removal effect for BPA and BPF, and through real sample verification, MCGC can be used for wastewater treatment. Therefore, MCGC is economical, environmentally friendly, and easy to separate and collect, and has suitable stability and broad application prospects.

Development of ZnO/Na-Montmorillonite Hybrid Nanostructures Used for PVOH/ZnO/Na-Montmorillonite Active Packaging Films Preparation via a Melt-Extrusion Process

Nowadays, the shelf-life extension of foods is a topic of major interest because of its environmental and economic benefits. For this purpose, various methods like deep-freezing, ultra-high-temperature pasteurization, drying methods, use of chemicals, controlled-atmosphere preservation, ionizing irradiation, and were investigated. During the last years, the smart packaging for foods using natural biodegradable components is of great interest because it provides positive environmental fingerprint and high shelf-life extension. In the present work, a new nanostructured composite material, the ZnO/Na-Montmorillonite hybrid, was developed. The high antimicrobial properties of the 3-D ZnO material in combination with the high barrier and strength properties of the 2-D Na-Montmorillonite material provided a high promising component for food smart packaging applications. As an extra innovation of this process, the ZnO nanorods coated the external surface of the Na-Montmorillonite and it was not intercalated into the clay as a pillaring material. This new material was incorporated with a 3% w/w composition with a biodegradable poly(vinyl)alcohol (PVOH) polymeric matrix which also exhibits antimicrobial activity. The final product was tested via XRD, FTIR, SEM, tensile test, water sorption, water vapor permeability, oxygen permeability UV–vis, and anti-microbial activity tests and it exhibited advanced mechanical and antimicrobial properties, especially for a ZnO/Na-Montmorillonite fraction of 4:1.

Chitosan functionalized magnetic graphene oxide nanocomposite for the sensitive and effective determination of alkaloids in hotpot

Chitosan functionalized magnetic graphene oxide nanocomposite (Fe₃O₄@SiO₂@CS/GO) was successfully fabricated via a facile amide reaction between chitosan and graphene oxide. A novel extraction method using Fe₃O₄@SiO₂@CS/GO as nanoadsorbent was developed and applied to the efficient extraction and determination of multiple alkaloids from the complex matrix. The composition and structure of the nanoadsorbent was systematically characterized by various techniques. The nanoadsorbent possesses performances of high efficiency, easy operation, superparamagnetism, environment friendly and economic feasibility. The adsorption mechanism for alkaloids included π-π electron-donor-acceptor interaction, cation-π interaction and hydrogen bonding. The principal parameters influencing extraction procedure such as adsorbent dosage, pH, adsorption time, desorption conditions and regeneration cycles were investigated and optimized. Under the optimized conditions, the method exhibited good linear dynamic range with correlation coefficient (r²) higher than 0.997 and the limit of detection (LOD) was among 0.016--0.092 μg kg^-1. Intra- and inter-day relative standard deviations (RSDs) were <10%. These results indicated that the developed method was successfully applied for simultaneous detection of alkaloids in hotpot. This study provided valuable guidance and effective method for the analysis of alkaloids in intricate interference system.

Current advancements in chitosan-based film production for food technology; A review

Chitosan is obtained from chitin, which could be considered to be the most abundant polymer after cellulose. Owing to these properties, chitosan alone or chitosan-based composite film production is attaining huge attention in terms of applications from researchers and industrialists coming from divergent fields. To enhance the biological (mainly antimicrobial and antioxidant) and physiological (mainly mechanical, thermal and barrier) attributes of the chitosan-based films, a vast medley of plant extracts and supporting polymers has been blended into chitosan films. Considering the up to date literature reports based on chitosan film production and applications, it can be stated that still, the research ratio is low in this field. Chitosan blend/composite films with specific properties (superhydrophobicity, excellent mechanical strength, acceptable barrier properties) can be produced only for specific applications in food technology. In the current review, we tried to summarize the advancements made in the last 5-7 years in the field of chitosan film technology for its application in the food industry.

Emerging Chitosan-Based Films for Food Packaging Applications

Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrier films, and sensing films have achieved great developments. This article comprehensively reviews recent advances in the preparation and application of engineered chitosan-based films in food packaging fields.

Preparation and Bioactivity Assessment of Chitosan-1-Acetic Acid-5-Flurouracil Conjugates as Cancer Prodrugs

5-fluorouracil (5-FU) is a specific anti-cancer agent that is generally used to treat gastrointestinal, colorectal, and breast cancer. In this work, chitosan (CS) was extracted from local fish scales using an established method. 5-FU was then converted to 1-acetic acid-5-fluorouracil (FUAC) and reacted with this CS to prepare chitosan-1-acetic acid-5-fluorouracil (CS-FUAC) conjugates as a colon-specific prodrug. All compounds were characterized by Proton nuclear magnetic resonance (¹H-NMR), Fourier-transform infrared (FTIR), and UV-visible spectroscopy. The synthesized compound was subjected to a chemical stability study in phosphate buffer (0.2 M, pH 7.4) and in KCl/HCl buffer (0.2 M, pH 1.2) at different time intervals (0–240 min) and incubation at 37 °C. This revealed a significantly greater stability and a longer half-life for the CS-FUAC than for FUAC. Hemolytic activity results indicated a much lower toxicity for CS-FUAC than for 5-FU and supported consideration of CS-FUAC for further biological screening and application trials. The percentage of FUAC in the conjugates was determined by subjecting the prodrug to treatment in basic media to hydrolyze the amide bond, followed by absorbency measurements at 273 nm. The cytotoxicity studies of the conjugates were also evaluated on human colorectal cancer cell line (HT-29), which showed that the conjugates are more cytotoxic than the free drug. Therefore, CS-FUAC conjugates can be considered to represent potential colon-specific drug delivery agents, with minimal undesirable side effects, for colon cancer therapy.