Chitosan-based nanocomposites: preparation and characterization for food packing industry

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.

Chitosan, chitosan derivatives, and chitosan-based nanocomposites: eco-friendly materials for advanced applications (a review)

For many years, chitosan has been widely regarded as a promising eco-friendly polymer thanks to its renewability, biocompatibility, biodegradability, non-toxicity, and ease of modification, giving it enormous potential for future development. As a cationic polysaccharide, chitosan exhibits specific physicochemical, biological, and mechanical properties that depend on factors such as its molecular weight and degree of deacetylation. Recently, there has been renewed interest surrounding chitosan derivatives and chitosan-based nanocomposites. This heightened attention is driven by the pursuit of enhancing efficiency and expanding the spectrum of chitosan applications. Chitosan's adaptability and unique properties make it a game-changer, promising significant contributions to industries ranging from healthcare to environmental remediation. This review presents an up-to-date overview of chitosan production sources and extraction methods, focusing on chitosan's physicochemical properties, including molecular weight, degree of deacetylation and solubility, as well as its antibacterial, antifungal and antioxidant activities. In addition, we highlight the advantages of chitosan derivatives and biopolymer modification methods, with recent advances in the preparation of chitosan-based nanocomposites. Finally, the versatile applications of chitosan, whether in its native state, derived or incorporated into nanocomposites in various fields, such as the food industry, agriculture, the cosmetics industry, the pharmaceutical industry, medicine, and wastewater treatment, were discussed.

Polysaccharides and proteins based bionanocomposites as smart packaging materials: From fabrication to food packaging applications a review

Food industry is the biggest and rapidly growing industries all over the world. This sector consumes around 40 % of the total plastic produced worldwide as packaging material. The conventional packaging material is mainly petrochemical based. However, these petrochemical based materials impose serious concerns towards environment after its disposal as they are nondegradable. Thus, in search of an appropriate replacement for conventional plastics, biopolymers such as polysaccharides (starch, cellulose, chitosan, natural gums, etc.), proteins (gelatin, collagen, soy protein, etc.), and fatty acids find as an option but again limited by its inherent properties. Attention on the initiatives towards the development of more sustainable, useful, and biodegradable packaging materials, leading the way towards a new and revolutionary green era in the food sector. Eco-friendly packaging materials are now growing dramatically, at a pace of about 10-20 % annually. The recombination of biopolymers and nanomaterials through intercalation composite technology at the nanoscale demonstrated some mesmerizing characteristics pertaining to both biopolymer and nanomaterials such as rigidity, thermal stability, sensing and bioactive property inherent to nanomaterials as well as biopolymers properties such as flexibility, processability and biodegradability. The dramatic increase of scientific research in the last one decade in the area of bionanocomposites in food packaging had reflected its potential as a much-required and important alternative to conventional petroleum-based material. This review presents a comprehensive overview on the importance and recent advances in the field of bionanocomposite and its application in food packaging. Different methods for the fabrication of bionanocomposite are also discussed briefly. Finally, a clear perspective and future prospects of bionanocomposites in food packaging were presented.

Cytotoxicity Enhancement of α-Mangostin with Folate-Conjugated Chitosan Nanoparticles in MCF-7 Breast Cancer Cells

α-mangostin (AM) is a promising natural anticancer agent that can be used in cancer research. However, its effectiveness can be limited by poor solubility and bioavailability. To address this issue, chitosan-based nanoparticles (CSNPs) have been investigated as a potential delivery system to enhance the cytotoxicity to cancer cells and improve selectivity against normal cells. In this study, we developed folate-conjugated chitosan nanoparticles (F-CS-NPs) using a carbodiimide-based conjugation method to attach folate to chitosan (CS), which have different molecular weights. The NPs were crosslinked using tripolyphosphate (TPP) via ionic gelation. To characterize the F-CS-NPs, we utilized various analytical techniques, including transmission electron microscopy (TEM) to evaluate the particle size and morphology, Fourier-transform infrared spectroscopy (FTIR) to confirm the presence of functional groups, and ultraviolet-visible spectroscopy (UV-Vis) to measure the absorption spectrum and confirm the presence of folate. The particle size of AM-F-CS-NPs ranged from 180 nm to 250 nm, with many having favorable charges ranging from +40.33 ± 3.4 to 10.69 ± 1.3 mV. All NPs exhibited the same spherical morphology. The use of F-CS-NPs increased drug release, followed by a sustained release pattern. We evaluated the cytotoxicity of AM, AM-F-CS-HMW, and AM-F-CS-LMW NPs against MCF-7 cells and found IC50 values of 8.47 ± 0.49, 5.3 ± 0.01, and 4.70 ± 0.11 µg/mL, respectively. These results confirm the improved cytotoxicity of AM in MCF-7 cells when delivered via F-CS-NPs. Overall, our in vitro study demonstrated that the properties of F-CS-NPs greatly influence the cytotoxicity of AM in MCF-7 breast cancer cells (significantly different (p < 0.05)). The use of F-CS-NPs as a drug-delivery system for AM may have the potential to develop novel therapies for breast cancer.

Intercalated chitosan-ionic liquid ionogel in SnO nanoplate: band gap narrow and adsorption-photodegradation process

Ionogels are a category of hybrid material containing ionic liquid stabilized by polymeric network. These composites have some applications in solid-state, energy storage devices and environmental studies. In this research, chitosan (CS), ethyl pyridinium iodide ionic liquid (IL), and ionogel (IG) consisting of chitosan and ionic liquid were used in the preparation of a SnO nanoplate (SnO-IL, SnO-CS and SnO-IG). For the preparation of the ethyl pyridinium iodide, a mixture of pyridine and iodoethane (1: 2 molar ratio) was refluxed for 24 hours. The ionogel was formed using ethyl pyridinium iodide ionic liquid in chitosan that was dissolved in acetic acid (1 % v/v). By increasing NH₃∙H₂O, the pH of the ionogel reached 7-8. Then, the resultant IG was mixed with SnO in an ultrasonic bath for 1 h. The microstructure of the ionogel was involved as assembled unit via π-π, electrostatic and hydrogen bonding interactions to be three-dimensional networks. The intercalated ionic liquid and chitosan influenced the stability of the SnO nanoplates and improved band gap values. When chitosan was contained as the interlayer space of the SnO nanostructure, the resulting biocomposite formed a well-ordered flower-like SnO structure. These hybrid material structures were characterized by FT-IR, XRD, SEM, TGA, DSC, BET, and DRS techniques. The changes in the band gap values for photocatalysis applications were investigated. In the case of SnO, SnO-IL, SnO-CS, and SnO-IG, the band gap energy was 3.9, 3.6, 3.2, and 2.8 eV, respectively. The dye removal efficiency of SnO-IG was 98.5, 98.8, 97.9, and 98.4 % via the second-order kinetic model for Reactive Red 141, Reactive Red 195, Reactive Red 198, and Reactive Yellow 18, respectively. The maximum adsorption capacity of SnO-IG was 540.5, 584.7, 1501.5, and 1100.1 mg/g for Red 141, Red 195, Red 198, and Yellow 18 dyes, respectively. Also, an acceptable result (96.47 % dye removal) was obtained with the prepared SnO-IG biocomposite for dye removal from textile wastewater.

Green chemistry principles for the synthesis of anti fungal active gum acacia-gold nanocomposite - natamycin (GA-AuNC-NT) against food spoilage fungal strain Aspergillus ochraceopealiformis and its marked Congo red dye adsorption efficacy

In this present study, a highly stable gum acacia -gold nanocomposite fabricated with food preservative agent natamycin (GA-AuNC-NT) was prepared via green science principles under in vitro conditions. Various characterisation techniques reveal highly stable structural, functional properties of the synthesised nanocomposite with marked antifungal activity and adsorption efficacy against congo red dye. The antifungal activity was investigated against the fungal strain Aspergillus ochraceopealiformis isolated from spoiled, expired bread. The well diffusion assay, fungal hyphae fragmentation assay and spore germination inhibition assay were used to determine the antifungal activity of the synthesised nanocomposite. Potential antifungal activity of the synthesised nanocomposite was confirmed by recording zone of inhibition, high rate of hyphae fragmentation and marked spore germination inhibition against the tested fungal strain. The molecular mechanism of antifungal activity was studied by measuring oxidative stress marker genes like catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) induction adopting quantitative real-time polymerase chain reaction (q RT-PCR). Among the various treatment, a notable reduction in all the tested marker genes expression was recorded in the nanocomposite treated fungal strain. Release profile studies using different solvents reveals sustained or controlled release of natamycin at the increasing periods. The synthesised nanocomposite's high safety or biocompatibility was evaluated with the Wistar animal model by determining notable changes in behavioural, biochemical, haematological and histopathological parameters. The synthesised nanocomposite did not exhibit any undesirable changes in all the tested parameters confirming the marked biosafety or biocompatibility. The nanocomposite was coated on the bread packaging material. The effect of packaging on the proximate composition, antioxidative enzymes status, and fungal growth of bread samples incubated under the incubation period were studied. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies reveal that the nanocomposite was effectively coated on the packaging material without changing size, shape, and functional groups. No changes in the proximate composition and antioxidative enzymes of the packaged bread samples incubated under different incubation periods reveal the nanocomposite's marked safety. The complete absence of the fungal growth also indicates the uniqueness of the nanocomposite. Further, the sorption studies revealed the utilisation of Langmuir mechanism and pseudo II order model successfully The present finding implies that the synthesised nanocomposite can be used as an effective, safe food preservative agent and adsorbent of toxic chemicals.