Chitosan and gelatin based biodegradable packaging films with UV-light protection

Sustainable UV absorbing bio-plastic films by valorisation of humins and chitosan

Humins, an inevitable bio-refinery waste by-product of sugar dehydration have been efficiently utilized for the first time for developing biodegradable thin films for UV shielding. The films were prepared from chitosan, and humins, a novel combination, aiming towards simultaneous utilization of marine and bio-refinery waste, rendering simple, effective, robust UV absorbing films. The structure-activity relationship of these films were elucidated with the help of different analytical techniques like X-ray diffraction, Fourier transform infrared spectroscopy, Thermogravimetric analysis, UV-vis spectroscopy, Atomic force microscopy, Scanning electron microscopy, Tensile testing, Contact angle measurements and water absorption studies. Intrinsic biodegradability was studied using fungi i.e. Aspergillus niger. Different feedstocks (corncob, rice husk, glucose and xylose) were explored for generating humins. Amongst them, humins derived from xylose were utilized for the preparation of the bio-plastic films of chitosan. The results revealed that, addition of 5.0 % humins was observed to be an optimum concentration yielding films with excellent UV absorption, mechanical properties, and biodegradability. The current work is in perfect alignment with sustainability and green chemistry as it ameliorates waste valorization (lignocellulosic and marine altogether). Further, its innovation stems from the first-hand use of humins for UV absorption, novel combination of biopolymers, use of green raw materials.

Chitin and chitosan from North Pacific krill (Euphausia Pacifica): Comparative study of conventional and microwave-assisted extraction methods and the potential use in chitosan film production

The characteristics and prospective applications of North Pacific krill chitin and chitosan are currently unexplored, and their conventional isolation method is time- and energy-consuming. In this study, chitin and chitosan were extracted from North Pacific krill using conventional and microwave-assisted methods, followed by comprehensive characterisation and evaluation of chitosan film potential. The extracted chitin was identified as an α-polymorph, and chitosan exhibited a remarkable degree of deacetylation (90 %) in both methods. Microwave-assisted extraction provided comparable chitin and chitosan yields without adversely affecting their properties, and the resulting products also exhibited enhanced crystallinity and thermal stability. Moreover, microwave-assisted-extracted chitosan (MCS) had a significantly lower molecular weight (Mw). Krill chitosan films demonstrated superior performance as food packaging materials compared to films prepared from commercial chitosan, due to their greater extensibility and transparency. Notably, the MCS film exhibited exceptional antioxidant activity and solubility. These findings suggest that North Pacific krill holds promise as a viable source of α-chitin and chitosan, and microwave-assisted extraction is effective in producing low Mw chitosan that has the potential to be used for preparing functional biodegradable film, with a fivefold reduction in treatment time.

Development of Pectin-Based Films with Encapsulated Lemon Essential Oil for Active Food Packaging: Improved Antioxidant Activity and Biodegradation

This study evaluated the physicochemical, morphological, and functional properties of pectin-based films incorporated with lemon essential oil (EO) to assess their potential as biodegradable food packaging materials. The results showed that EO incorporation significantly influenced the film's characteristics. The control film exhibited a smooth surface, while the EO-containing film had a rougher texture with globular structures and interconnected channels, likely representing dispersed EO droplets and matrix alterations. The mechanical analysis revealed increased elongation at break (20.05 ± 0.784%) for EO-incorporated films, indicating improved flexibility, while tensile strength and Young's modulus decreased, suggesting reduced stiffness. Film thickness increased slightly with EO (0.097 ± 0.008 mm) compared to the control (0.089 ± 0.001 mm), though the difference was not statistically significant (p > 0.05). Moisture content decreased in EO-containing films (28.894%) compared to the control (35.236%), enhancing water resistance. Water solubility increased slightly (16.046 ± 0.003% vs. 15.315 ± 0.040%), while the swelling rate decreased significantly (0.189 ± 0.003 vs. 0.228 ± 0.040; p < 0.05), indicating greater structural stability in aqueous environments due to the hydrophobic nature of EO. Transparency tests showed that EO slightly increased film opacity (0.350 ± 0.02 vs. 0.290 ± 0.012), aligning with trends in UV-protective materials. The EO-incorporated films also exhibited moderate antibacterial activity against Staphylococcus aureus and Escherichia coli. Antifungal tests revealed strong inhibition of Botrytis cinerea (100%) and moderate inhibition of Alternaria alternata (50%) in EO-containing films. These results demonstrate that EO incorporation improves the functional properties of pectin films, enhancing their flexibility, antimicrobial activity, and environmental stability, making them promising candidates for sustainable food packaging applications. These novel active food packaging materials exhibit strong physical properties and significant potential in maintaining food quality and prolonging shelf life.

Stimuli-responsive Graphene-polysaccharide Nanocomposites for Drug Delivery and Tissue Engineering

Natural polysaccharide-based nanoparticles are known for their non-toxic nature and diverse medical applications. Graphene oxide (GO) nanoparticles show potential in cancer treatment due to their ability to target medication delivery and influence ROS generation. These nanocomposites are versatile in gene transport, therapy, and photodynamic therapy, especially when surface-modified. Proper dispersion and functionalization of GO in polymer matrices are crucial, with examples like hyaluronic acid-functionalized GO offering versatile platforms for cancer drug administration. The potential of graphene oxide extends to cancer phototherapy, electronic nanowires, hydrogels, antibacterial nanocomposites, and environmental applications. When activated by polysaccharides, graphene-based nanocomposites exhibit anti-inflammatory and anticancer properties, making them valuable across various industries, including water treatment.

Preparation and Characterization of New Biodegradable Packaging Materials Based on Gelatin Extracted from Tenualosa ilisha Fish Scales with Cellulose Nanocrystals

Food packaging industries generally use petroleum-based packaging materials that are non-biodegradable and harmful to the environment. Eco-friendly polymers such as chitosan (CH), gelatin (GE), and cellulose nanocrystals (CNCs) are leading viable alternatives to plastics traditionally used in packaging because of their higher functionality and biodegradability. In this study, an innovative approach has been disclosed to prepare new packaging materials by utilizing chitosan, gelatin, and cellulose nanocrystals (CNCs) through a simple solution casting method. GE and CNCs have been isolated from prawn shells and jute fiber, respectively. Utilization of Hilsa Tenualosa ilisha fish scale biowaste was a new and first approach for gelatin extraction. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis spectroscopy, and scanning electron microscopy (SEM) were used to examine the functional and morphological features of fish scale gelatin, chitosan, CNCs, and the resulting composite films. The synthesized film materials were analyzed for their mechanical strength, solubility, apparent density, swelling behavior, biodegradability, light transmittance, and transparency. The impregnation of CNCs into the polymer amalgam milieu effectively enhanced their physicochemical and biological properties. The degree of swelling in composite matrices was found to be increased gradually, whereas the solubility was decreased due to the cross-linking effect of CNCs. Elongation at break in the gelatin-chitosan (GC) film was observed as 48%. However, the incorporation of CNCs into the GC matrix potentially enhanced the elongation at break property to 64.05%, 62.86%, and 59.21% in GC1, GC2, and GC3 bioplastic films, respectively. The purified chitosan-gelatin films showed a tensile strength of 12.24 N/mm2, which was increased to 13.93 N/mm2 with the addition of 1.00% CNCs. The composite films were found to be highly transparent and stable in an ambient atmosphere. However, 49-60% deformation occurred in the composite materials after 7 days, whereas 71-84% biodegradation was realized after 21 days, when the respective composite films were subjected to a natural soil environment. These novel composite films possess all essential interesting features, such as biocompatibility, transparency, smoothness of surfaces, and biodegradability, making them suitable for use as packaging materials in different industries.

Carboxymethyl cellulose-chitosan edible films for food packaging: A review of recent advances

Polysaccharide-based edible films have been widely developed as food packaging materials in response to the rising environmental concerns caused by the extensive use of plastic packaging. In recent years, the integration of carboxymethyl cellulose (CMC) and chitosan (CS) for a binary edible film has received considerable interest because this binary edible film can retain the advantages of both constituents (e.g., the great oxygen barrier ability of CMC and moderate antimicrobial activity of CS) while mitigating their respective disadvantages (e.g., the low water resistance of CMC and poor mechanical strength of CS). This review aims to present the latest advancements in CMC-CS edible films. The preparation methods and properties of CMC-CS edible films are comprehensively introduced. Potential additives and technologies utilized to enhance the properties are discussed. The applications of CMC-CS edible films on food products are summarized. Literature shows that the current preparation methods for CMC-CS edible film are solvent-casting (main) and thermo-mechanical methods. The CMC-CS binary films have superior properties compared to films made from a single constituent. Moreover, some properties, such as physical strength, antibacterial ability, and antioxidant activity, can be greatly enhanced via the incorporation of some bioactive substances (e.g. essential oils and nanomaterials). To date, several applications of CMC-CS edible films in vegetables, fruits, dry foods, dairy products, and meats have been studied. Overall, CMC-CS edible films are highly promising as food packaging materials.

A Review of Chitosan-Based Materials for Biomedical, Food, and Water Treatment Applications

Chitosan, a natural biopolymer with excellent biocompatibility, biodegradability, and modifiable structure, has broad applications in regenerative medicine, tissue engineering, food packaging, and environmental technology. Its abundance, solubility in acidic solutions, and capacity for chemical modification make it highly adaptable for creating specialized derivatives with enhanced properties. Recent advances have demonstrated chitosan's efficacy in composite systems for tissue regeneration, drug delivery, and antimicrobial applications. This review examines chitosan's unique properties, with a focus on its antibacterial activity as influenced by factors like pH, concentration, molecular weight, and deacetylation degree. Additionally, chitosan's potential as a sustainable, non-toxic material for eco-friendly packaging and water treatment is explored, highlighting the growing interest in chitosan composites with other polymers and metallic nanoparticles for enhanced biomedical and environmental applications.

Gelatin-chitosan interactions in edible films and coatings doped with plant extracts for biopreservation of fresh tuna fish products: A review

The preservation of tuna fish products, which are extremely perishable seafood items, is a substantial challenge due to their instantaneous spoilage caused by microbial development and oxidative degradation. The current review explores the potential of employing chitosan-gelatin-based edible films and coatings, which are enriched with plant extracts, as a sustainable method to prolong the shelf life of tuna fish products. The article provides a comprehensive overview of the physicochemical properties of chitosan and gelatin, emphasizing the molecular interactions that underpin the formation and functionality of these biopolymer-based films and coatings. The synergistic effects of combining chitosan and gelatin are explored, particularly in terms of improving the mechanical strength, barrier properties, and bioactivity of the films. Furthermore, the application of botanical extracts, which include high levels of antioxidants and antibacterial compounds, is being investigated in terms of their capacity to augment the protective characteristics of the films. The study also emphasizes current advancements in utilizing these composite films and coatings for tuna fish products, with a specific focus on their effectiveness in preventing microbiological spoilage, decreasing lipid oxidation, and maintaining sensory qualities throughout storage. Moreover, the current investigation explores the molecular interactions associated with chitosan-gelatin packaging systems enriched with plant extracts, offering valuable insights for improving the design of edible films and coatings and suggesting future research directions to enhance their effectiveness in seafood preservation. Ultimately, the review underscores the potential of chitosan-gelatin-based films and coatings as a promising, eco-friendly alternative to conventional packaging methods, contributing to the sustainability of the seafood industry.

Innovative chitosan-onion polysaccharide composite films: A study on the preservation effects on cherry tomatoes

Natural preservation materials have long been a focus of research in the quality control of fruits and vegetables. This study aimed to develop composite films with exceptional preservation properties by utilizing chitosan (CS) as the film-forming material and incorporating onion polysaccharide (ONP) as the active component. The CS-ONP composite films were prepared, and their performance and preservation effects were evaluated. The results demonstrated that increasing the ONP content significantly enhanced the shading, antimicrobial, and antioxidant capabilities of the CS-ONP composite films. Preservation experiments revealed that the CS-ONP composite films effectively delayed the quality decline of cherry tomatoes during storage. However, despite the improvements brought by ONP, certain drawbacks persisted, such as reduced mechanical properties and alterations in surface structure. In summary, the CS-ONP composite films exhibit promising potential as novel materials for fruit and vegetable preservation. PRACTICAL APPLICATION: The spoilage of fruits and vegetables can cause huge economic losses. This study addresses this challenge by using chitosan as the film-forming substrate and adding crude onion polysaccharide as the active ingredient to create composite films. The preservation effects of these films on cherry tomatoes were studied. Although only cherry tomatoes were tested in this study, the composite films demonstrated significant potential for broader applications in fruit and vegetable preservation.

Influence of Curcuma Longa extract in citral addition on functional properties of thin films with triple-layer structure based on furcellaran and gelatin

In this study, we obtained triple-layer films based on furcellaran and gelatin, in which the middle layer was enriched with extract of Curcuma longa in citral. This newly developed material underwent a comprehensive characterisation process to identify significant improvements in its functional properties. Both SEM, XRD and FTIR analyzes indicated the formation of interactions not only between the components but also between the film layers. Notably, the incorporation of the natural extract led to a significant reduction in solubility, decreasing it from 74.79 % to 57.25 %, while enhancing thermal stability expressed as a melting point elevating it from 147.10 °C in the control film to 158.80 °C in the film with the highest concentration of the active ingredient. Simultaneously, the addition of this active ingredient resulted in decreased water contact angle (WCA) values, rendering the film more hydrophilic. The produced films exhibit great promise as packaging materials, particularly within the food industry, and the conducted research is marked by its forward-looking and developmental approach.

Designing of chitosan/gelatin based nanocomposite films integrated with Vachellia nilotica gum carbon dots for smart food packaging applications

Microbial growth and exposure to UV light is a persistent global concern resulting in food spoilage, therefore, smart packaging is crucial for the availability of safer and quality food. Present work describes fabrication of chitosan (CH) and gelatin (GL) based nanocomposite films by introducing green source, highly fluorescent Vachillia nilotica gum-derived carbon dots (VNG-CDs). The VNG-CDs and incorporated CH/GL nanocomposite films were characterized by UV-Visible, FTIR, XRD, SEM and TGA analysis. The FTIR and XRD data revealed that VNG-CDs, chitosan, gelatin, and glycerol are combined/interlinked to form homogeneous nanocomposite films. The inclusion of VNG-CDs to CS/GL-CDs nanocomposite film efficiently enhanced the thermal stability and improved mechanical properties. VNG-CDs added to films markedly blocked the ultraviolet light and their effectiveness improved as concentration of CDs increases, being >90 % in UVC (200-280 nm) region. The prepared CS/GL-CDs nanocomposite films manifested radical scavenging activity, reducing capability and also excellently inhibited growth of E. coli, K. pneumonia and S. aureus bacteria. The viability of CS/GL-CDs nanocomposite films examined using banana as a model fruit extending the storage time by two weeks. In conclusion, CH/GL films containing VNG-CDs can be developed into smart packaging materials with enhanced protection and antimicrobial properties.

Improvement of cross-linked films based on chitosan/diepoxy-poly (ethylene glycol) incorporating trans-cinnamaldehyde essential oil: Preparation, properties, and application in banana storage

In this study, development of bioactive coatings containing 1 % (w/v) chitosan (CS), 0.6 % (w/v) diepoxy-polyethylene glycol (PEG), and trans-cinnamaldehyde (CIN) was achieved. The physicochemical and biological properties of the coatings were investigated. The tensile strength, light transmission, water vapor permeability (WVP), and antibacterial properties were enhanced by the incorporation of CIN. The CIN-containing films appeared compact and rough, as observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the quality attributes of the bananas were evaluated at room temperature for 24 days, and the results showed that the CS/PEG/CIN coating delayed the respiration peak, weight loss, sugar content loss, and maintained firmness, color, total soluble solids (TSS), titratable acid (TA), and the appearance of the bananas. Principal component analysis (PCA) revealed that the bioactive coating significantly affected the respiration rate and weight loss of bananas.

Simultaneous Optimization of Deacetylation Degree and Molar Mass of Chitosan from Shrimp Waste

Shrimp waste is a valuable source for chitin extraction and consequently for chitosan preparation. In the process of obtaining chitosan, a determining step is the chitin deacetylation. The main characteristic of chitosan is the degree of deacetylation, which must be as high as possible. The molar mass is another important parameter that defines its utilizations, and according to these, high or low molar masses are required. The present study is an attempt to optimize the deacetylation step to obtain chitosan with a high degree of deacetylation and high or low molar mass. The study was carried out based on experimental data obtained in the frame of a central composite design where three working parameters were considered: NaOH concentration, liquid:solid ratio, and process duration. The regression models defined for the degree of deacetylation (DD) and for the mean molar mass (MM) of chitosan powders were used in the formulation of optimization problems. The objectives considered were simultaneous maximum DD and maximum/minimum MM for the final chitosan samples. For these purposes, multiobjective optimization problems were formulated and solved using genetic algorithms implemented in Matlab®. The multiple optimal solutions represented by trade-offs between the two objectives are presented for each case.

Animal derived biopolymers for food packaging applications: A review

It is essential to use environment-friendly, non-toxic, biodegradable and sustainable materials for various applications. Biopolymers are derived from renewable sources like plants, microorganisms, and agricultural wastes. Unlike conventional polymers, biopolymer has a lower carbon footprint and contributes less to greenhouse gas emission. All biopolymers are biodegradable, meaning natural processes can break them down into harmless products such as water and biomass. This property is of utmost importance for various sustainable applications. This review discusses different classifications of biopolymers based on origin, including plant-based, animal-based and micro-organism-based biopolymers. The review also discusses the desirable properties that are required in materials for their use as packaging material. It also discusses the different processes used in modifying the biopolymer to improve its properties. Finally, this review shows the recent developments taking place in using specifically animal origin-based biopolymer and its use in packaging material. It was observed that animal-origin-based biopolymers, although they possess unique properties however, are less explored than plant-origin biopolymers. The animal-origin-based biopolymers covered in this review are chitosan, gelatin, collagen, keratin, casein, whey, hyaluronic acid and silk fibroin. This review will help in renewing research interest in animal-origin biopolymers. In summary, biopolymer offers a sustainable and environment-friendly alternative to conventional polymers. Their versatility, biocompatibility will help create a more sustainable future.

Oyster-inspired carbon dots-functionalized silica and dialdehyde chitosan to fabricate a soy protein adhesive with high strength, mildew resistance, and long-term water resistance

Developing multifunctional adhesives with exceptional cold-pressing strength, water resistance, toughness, and mildew resistance remains challenging. Herein, inspired by oysters, a multifunctional organic-inorganic hybrid soybean meal (SM)-based adhesive was fabricated by incorporating amino-modified carbon dots functionalized silica nanoparticles (CDs@SiO2) and dialdehyde chitosan (DCS) into SM matrix. DCS effectively enhanced the interface interactions of organic-inorganic phases and the rigid nanofillers CDs@SiO2 uniformly dispersed in the SM matrix, which provided energy dissipation to improve the adhesive's toughness. Owing to the stiff skeleton structure and enhanced crosslinking density, the crosslinker-modified SM (MSM)/DCS/CDs@SiO2-2 wood adhesive exhibited outstanding cold-pressing strength (0.74 MPa), wet shear strength (1.36 MPa), and long-term water resistance (49 d). Additionally, the resultant adhesive showed superior antimildew and antibacterial properties benefiting from the introduction of DCS. Intriguingly, the fluorescent properties endowed by carbon dots further broadened the application of adhesives for realizing security testing. This study opens a new pathway for the synthesis of multifunctional biomass adhesives in industrial and household applications.

Biodegradable nano-reinforced packaging with improved functionality to extend the freshness and longevity of Plums Oemleria cerasiformis

Food packaging reinforced with Zn-doped TiO2 nanoparticles with enhanced prerequisite film-forming and biodegradable traits was prepared to augment fresh food storage. Pure and tailored metal (Zinc, Copper, and Selenium) doped TiO2 nanoparticles were synthesized and analyzed through multiple characterization techniques (optical spectra, XRD patterns (X-Ray Diffraction), Dynamic Light Scattering, and Scanning Electron Microscopy). The synthesized nanoparticles were tested for their Minimum Inhibitory Concentrations, antimicrobial potential against common lethal food pathogens, and cytotoxicity. Compared to Cu- and Se-doped nanoparticles, Zn-doped TiO2 nanoparticles displayed the most potent antimicrobial activity with insignificant cytotoxicity and were incorporated into the food packaging materials. The developed nano-reinforced food packaging efficaciously augmented the freshness of plums (Oemleria cerasiformis) for 16 days (42 ± 2 °C). The physicomechanical characterization of the nano-reinforced packaging establishes its utility in food packaging applications. The developed biodegradable packaging undergoes complete decomposition within 12 days of storage in natural soil.

Preparation of chitosan/gelatin-based functional films integrated with carbon dots from banana peel for active packaging application

Carbon dots (CDs) were manufactured with banana peels using a hydrothermal method (200 °C for 6 h). The synthesized CDs were spherical particles with a size of 1-3 nm having carboxyl groups and amine groups on the surface. CDs have been impregnated into chitosan/gelatin films to synthesize multifunctional packaging films. The composite film showed a slight decrease in transparency but a significant increase in UV protection properties. The fabricated film displayed strong antioxidant efficacy showing >74 % DPPH and 99 % ABTS radical scavenging potential. The film also unveiled substantial antibacterial activity against the foodborne pathogenic bacteria, Listeria monocytogenes, fully eliminating the growth of these bacteria within 6 h of exposure. The chitosan/gelatin film containing CD was used for minced meat packaging, and the film delayed bacterial growth (< 1 Log CFU/g after 24 h) and maintained the meat color even after 24 h of storage at 20 °C. The CD-added chitosan/gelatin functional film has a high probability of application in active food packaging, especially for extending the shelf life of packaged meat and maintaining its aesthetic quality.

Comparison of chitosan and gelatin-based films and application to antimicrobial coatings enriched with grapefruit seed extract for cherry tomato preservation

Bio-based single, composite, and bilayer edible films were developed based on chitosan and gelatin, including grapefruit seed extract (GSE) as an antimicrobial agent. The physicochemical and antimicrobial properties of films were analyzed, and it was found that compounding and laminating two polymers could enhance their physicochemical properties. The composite film was strong, endurable, and flexible compared with the single ones. In addition, the composite and bilayer films had lower water vapor permeability than the single ones. Edible films and coatings with GSE presented a greater bactericidal effect than the inactive ones. In addition, the hardness, weight, and color changes of the coated cherry tomatoes during 7-day storage did not differ, whereas a bacterial reduction against Salmonella Typhimurium was revealed. Taken together, composite and bilayer films with CH and GL and enriched with GSE were developed for food packaging applications, and it showed improved mechanical, water barrier, and antimicrobial properties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01254-9.

Remediation plan of nano/microplastic toxicity in food

Microplastic pollution is causing a stir globally due to its persistent and ubiquitous nature. The scientific collaboration is diligently working on improved, effective, sustainable, and cleaner measures to control the nano/microplastic load in the environment especially wrecking the aquatic habitat. This chapter discusses the challenges encountered in nano/microplastic control and improved technologies like density separation, continuous flow centrifugation, oil extraction protocol, electrostatic separation to extract and quantify the same. Although it is still in the early stages of research, biobased control measures, like meal worms and microbes to degrade microplastics in the environment have been proven effective. Besides the control measures, practical alternatives to microplastics can be developed like core-shell powder, mineral powder, and biobased food packaging systems like edible films and coatings developed using various nanotechnological tools. Lastly, the existing and ideal stage of global regulations is compared, and key research areas are pinpointed. This holistic coverage would enable manufacturers and consumers to reconsider their production and purchase decisions for sustainable development goals.

Physicochemical properties of soybean β-conglycinin-based films affected by linoleic acid

To explore the interaction between lipids and proteins during emulsion film formation, the linoleic acid concentration effects on the physicochemical properties of soybean β-conglycinin (7S) films were studied. The viscosity and size of oil droplets in the film-forming solution gradually increased with the increasing linoleic acid concentration. As the linoleic acid concentration increased, the number of oil droplets on the film surfaces and elongation at break of films gradually increased, whereas the tensile strength decreased. The films containing 20% linoleic acid had the highest water vapor permeability value, which was decreased by increasing or decreasing the linoleic acid concentration. According to the molecular dynamics simulation and chemical interactions, 7S could be adsorbed at the linoleic acid interface and bind stably, resulting in the decreased ionic and hydrogen bonds but the increased hydrophobic interactions and covalent bonds among proteins in the films.

Chitosan-Mediated Environment-Friendly Synthesis of Gold Nanoparticles with Enhanced Photonic Reactivity

We developed a very simple, efficient and environment-friendly synthesis method for the manufacturing of high-performance chitosan-capped gold nanoparticles that could be used for biosensing applications. Gold nanoparticles were prepared through the spontaneous reduction of chloroauric acid by chitosan, which was used as both a reducing and a stabilizing agent. The samples were heated to a temperature of 60 °C under ultrasonic conditions. The composite system made of chitosan as a matrix and gold nanoparticles demonstrated a high stability in an aqueous buffer solution. The nanoparticles displayed an enhancement in photonic performance compared with the same property of individual components as a result of surface plasmon resonance at the interface between the structural phases of the hybrid structure. The enhanced photonic reactivity of the hybrid nanostructure may offer new insights for future possible biosensing applications.

Active Packaging Films Made by Complex Coacervation of Tragacanth Gum and Gelatin Loaded with Curcumin; Characterization and Antioxidant Activity

The development of biopolymer-based green packaging films has gained remarkable attention in recent years. In this study, curcumin active films were prepared using different proportions of gelatin (GE) and a soluble fraction of tragacanth gum (SFTG) (1GE:1SFTG and 2GE:1SFTG) by complex coacervation. The various ratios of used biopolymers did not significantly impact the mechanical properties, thickness, and WVP of final films. However, biopolymers' ratio impacted the moisture content, water solubility, swelling ratio, and release rate. Blending curcumin with biopolymers caused a reduction in tensile strength (from 1.74 MPa to 0.62 MPa for film containing 1GE:1SFTG and from 1.77 MPa to 0.17 MPa for film containing 2GE:1SFTG) and proliferation in elongation at break (from 81.48% to 122.00% for film containing 1GE:1SFTG and from 98.87% to 109.58% MPa for film containing 2GE:1SFTG). Moisture content and water solubility of films experienced a decrease after the addition of curcumin. Antioxidant activity of curcumin-loaded films was almost five times higher than neat film samples. Furthermore, the interreaction between the carboxylic group of SFTG and amide I of GE formed an amide linkage and was proven by FTIR analysis. TGA showed a drop in the thermal stability of film samples compared to the main ingredients. In general, the complex coacervate of SFTG and GE has the advantage of developing eco-friendly and low-cost packaging film in the food industry, especially for the protection of fatty foods.

Hydrophobisation of Silica Nanoparticles Using Lauroyl Ethyl Arginate and Chitosan Mixtures to Induce the Foaming Process

We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the partial hydrophobisation of their surface, which favoured their attachment to the surface of a thin foam film. It was found that the presence of small and medium-sized (6–9 nm) hydrophobic particles in the interfacial layer of lamella foam film inhibited the coalescence and coarsening processes, which prolonged the life of the foam. Furthermore, hydrophobising of 30 nm particles allowed the formation of large aggregates precipitating from the mixture under steady-state conditions. These aggregates, however, under the conditions of the dynamic froth flotation process in the foam column, were floated into the foam layer. As a result, they were trapped in the foam film and Plateau borders, effectively preventing liquid leakage out of the foam. These results demonstrate the efficiency of using chitosan-LAE mixtures to remove silica nanoparticles from aqueous phase by foaming and flotation.

Obtention of New Edible Biofilms from Water Kefir Grains in Comparison with Conventional Biofilms from Taro (Colocasia esculenta) and Cassava (Manihot esculenta) Starch

Microorganism biomass is a sustainable and innovative source of biopolymers, such as proteins and polysaccharides, that is suitable for the development of biodegradable films. The aim of this research was to evaluate the synthesis, morphology, rheology, and morphological and mechanical properties on the production of edible biofilms based on water kefir grains, and compare them with edible films based on thermoplastic compounds from starch (TPS) obtained from taro (Colocasia esculenta) and cassava (Manihot esculenta). Edible biofilms were prepared in solution with 30% wt/wt glycerol relative to starch mass and kefir grain biofilms using the casting method. A stationary rheological analysis was performed on the film-forming suspensions of kefir, taro starch, and cassava starch. Once the films were obtained, a physicochemical and morphological characterization was carried out. Results of the characterization showed the following main aspects: The results indicated an increase in biomass production using muscovado and pineapple peel. The film-forming suspensions had a dilating behavior; however, the results obtained not only show the viscoelastic behavior but also the elastic limit (σ0), which varied from 0.077 to 0.059 Pa for suspensions of water kefir grains and from 0.077 to 0.072 Pa for starch suspensions. These elastic limit variations can be defined as the minimum shear stress required to start the flow, and all these rheological data were adjusted to the Herschel–Bulkley model; the morphological and mechanical characterization of the films obtained showed homogeneous surfaces with transparency and without cracks; regarding the water activity, values lower than 6 were obtained, which indicates that there will be no growth of any microorganism, and the hardness data showed differences between those obtained from kefir and taro and cassava starch. The similar results of the rheological characterization in the formation of the kefir biofilm and the conventional edible starch films, in addition to the similar results in the water activity below 6 and the hardness, points to an attractive alternative capable of replacing the conventional materials with a mass production of biofilms of probiotic microorganisms. The results also revealed that water kefir grains biomass is a viable and innovative source of biodegradable materials, and these grains can be an alternative to conventional established starch materials.

Chitosan-Gelatin Films Cross-Linked with Dialdehyde Cellulose Nanocrystals as Potential Materials for Wound Dressings

In this study, thin chitosan-gelatin biofilms cross-linked with dialdehyde cellulose nanocrystals for dressing materials were received. Two types of dialdehyde cellulose nanocrystals from fiber (DNCL) and microcrystalline cellulose (DAMC) were obtained by periodate oxidation. An ATR-FTIR analysis confirmed the selective oxidation of cellulose nanocrystals with the creation of a carbonyl group at 1724 cm-1. A higher degree of cross-linking was obtained in chitosan-gelatin biofilms with DNCL than with DAMC. An increasing amount of added cross-linkers resulted in a decrease in the apparent density value. The chitosan-gelatin biofilms cross-linked with DNCL exhibited a higher value of roughness parameters and antioxidant activity compared with materials cross-linked with DAMC. The cross-linking process improved the oxygen permeability and anti-inflammatory properties of both measurement series. Two samples cross-linked with DNCL achieved an ideal water vapor transition rate for wound dressings, CS-Gel with 10% and 15% addition of DNCL-8.60 and 9.60 mg/cm2/h, respectively. The swelling ability and interaction with human serum albumin (HSA) were improved for biofilms cross-linked with DAMC and DNCL. Significantly, the films cross-linked with DAMC were characterized by lower toxicity. These results confirmed that chitosan-gelatin biofilms cross-linked with DNCL and DAMC had improved properties for possible use in wound dressings.

Recent Advances in Bio-Based Smart Active Packaging Materials

The shortage of oil resources is currently a global problem. The use of renewable resources instead of non-renewable ones has become a hot topic of research in the eyes of scientists. In the food industry, there is a lot of interest in bio-based smart active packaging that meets the concept of sustainability and ensures safety. The packaging has antibacterial and antioxidant properties that extend the shelf life of food. Its ability to monitor the freshness of food in real time is also beneficial to consumers’ judgement of food safety. This paper summarises the main raw materials for the preparation of bio-based smart active packaging, including proteins, polysaccharides and composite materials. The current status of the preparation method of bio-based smart active packaging and its application in food preservation is summarised. The future development trend in the field of food packaging is foreseen, so as to provide a reference for the improvement of bio-based smart active packaging materials.

Recent Advancements in Smart Biogenic Packaging: Reshaping the Future of the Food Packaging Industry

Due to their complete non-biodegradability, current food packages have resulted in major environmental issues. Today’s smart consumer is looking for alternatives that are environmentally friendly, durable, recyclable, and naturally rather than synthetically derived. It is a well-established fact that complete replacement with environmentally friendly packaging materials is unattainable, and bio-based plastics should be the future of the food packaging industry. Natural biopolymers and nanotechnological interventions allow the creation of new, high-performance, light-weight, and environmentally friendly composite materials, which can replace non-biodegradable plastic packaging materials. This review summarizes the recent advancements in smart biogenic packaging, focusing on the shift from conventional to natural packaging, properties of various biogenic packaging materials, and the amalgamation of technologies, such as nanotechnology and encapsulation; to develop active and intelligent biogenic systems, such as the use of biosensors in food packaging. Lastly, challenges and opportunities in biogenic packaging are described, for their application in sustainable food packing systems.

Recent advances of emerging green chitosan-based biomaterials with potential biomedical applications: A review

Chitosan is the most abundant natural biopolymer, after cellulose. It is mainly derived from the fungi, shrimp's shells, and exoskeleton of crustaceans, through the deacetylation of chitin. The ecological sustainability associated with its exercise and the flexibility of chitosan owing to its active functional hydroxyl and amino groups makes it a promising candidate for a wide range of applications through a variety of modifications. The biodegradability and biocompatibility of chitosan and its derivatives along with their various chemical functionalities make them promising carriers for pharmaceutical, nutritional, medicinal, environmental, agriculture, drug delivery, and biotechnology applications. The present work aims to provide a detailed and organized description of modified chitosan and its derivatives-based nanomaterials for biomedical applications. We addressed the biological and physicochemical benefits of nanocomposite materials made up of chitosan and its derivatives in various formulations, including improved physicochemical stability and cells/tissue interaction, controlled drug release, and increased bioavailability and efficacy in clinical practice. Moreover, several modification techniques and their effective utilization are also reviewed and collected in this review.

Chitosan/Gelatin/Silver Nanoparticles Composites Films for Biodegradable Food Packaging Applications

The food packaging industry explores economically viable, environmentally benign, and non-toxic packaging materials. Biopolymers, including chitosan (CH) and gelatin (GE), are considered a leading replacement for plastic packaging materials, with preferred packaging functionality and biodegradability. CH, GE, and different proportions of silver nanoparticles (AgNPs) are used to prepare novel packaging materials using a simple solution casting method. The functional and morphological characterization of the prepared films was carried out by using Fourier transform infrared spectroscopy (FTIR), UV–Visible spectroscopy, and scanning electron microscopy (SEM). The mechanical strength, solubility, water vapor transmission rate, swelling behavior, moisture retention capability, and biodegradability of composite films were evaluated. The addition of AgNPs to the polymer blend matrix improves the physicochemical and biological functioning of the matrix. Due to the cross-linking motion of AgNPs, it is found that the swelling degree, moisture retention capability, and water vapor transmission rate slightly decrease. The tensile strength of pure CH–GE films was 24.4 ± 0.03, and it increased to 25.8 ± 0.05 MPa upon the addition of 0.0075% of AgNPs. The real-time application of the films was tested by evaluating the shelf-life existence of carrot pieces covered with the composite films. The composite film containing AgNPs becomes effective in lowering bacterial contamination while comparing the plastic polyethylene films. In principle, the synthesized composite films possessed all the ideal characteristics of packaging material and were considered biodegradable and biocompatible food packaging material and an alternate option for petroleum-based plastics.

Chitosan derivatives-based films as pH-sensitive drug delivery systems with enhanced antioxidant and antibacterial properties

The purpose of this study was to develop and characterize chitosan (Ch)-based films incorporated with varying molecular weight (Mw) and acetylation degree (AD) chitosan-depolymerization-products (CDP), to be applied as drug delivery materials. As compared to Ch-film, optical and antioxidant potentials of Ch/CDP-based films were improved, particularly using low Mw and AD-CDP. Whereas, films water resistance, mechanical and antibacterial properties increased as CDP-Mw increased and AD decreased. For the thermal and swelling behaviors, better values were obtained using higher Mw and AD-CDP. Further, to assess their in vitro ciprofloxacin (CFX)-release behavior, loaded-CFX Ch/CDP-based films, crosslinked using glutaraldehyde, were prepared. Expect of elongation at break, crosslinked CFX-loaded films showed increased optical, water resistance, tensile strength and thermal properties, as compared to unloaded films. The CFX-release profiles indicated that a slower and sustained release was observed, particularly when using lower Mw and AD-CDP, and mainly for the crosslinked films during 48 h. These films can release CFX for up to 54% in 6 and 24 h, at pH 1.2 and 7.4, respectively. Through this study, novel biodegradable, swellable and pH-sensitive crosslinked Ch/CDP-based films may be considered as suitable and promising drug delivery systems.

Effect of Edible Carboxymethyl Chitosan-Gelatin Based Coating on the Quality and Nutritional Properties of Different Sweet Cherry Cultivars during Postharvest Storage

Sweet cherry has many cultivars with different storability and nutritional properties. To reveal the reasons for the differences in storability among cultivars and improve the quality of sweet cherries, the surface microstructure of four representative sweet cherry cultivars (Red Light, Ranier, Red Agate, Friendship) epidermis and peduncle at harvest were examined and the effects of carboxymethyl chitosan-gelatin (CMCS-GL) based edible coating incorporating CaCl2 and ascorbic acid (AA) (AA-CaCl2-CMCS-GL) on the quality and nutritional characteristics of sweet cherry were evaluated. Results showed there were significant differences in the wax distribution of the epidermis and the number of stomata on the peduncle surface between four cultivars of sweet cherries at harvest, which was closely related to fruit decay ratio during storage. AA-CaCl2-CMCS-GL coating delayed the onset of decay and the fruit decay ratio in coated groups (3.0%–15.3%) was significantly lower than in control groups (17.7%–63.0%) after 33 d storage. The coating also helped to maintain the quality and nutritional characteristics of four sweet cherry cultivars, including reducing weight loss, maintaining better skin color, peduncle freshness, higher fruit firmness, titratable acidity, AA, total phenolics content, total anthocyanins concentration, and antioxidant capacity. These results suggested that AA-CaCl2-CMCS-GL coating could be considered as a new preservation method for improving postharvest quality and nutritional properties of different sweet cherry cultivars.

Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

In Vivo Cartilage Regeneration with Cell-Seeded Natural Biomaterial Scaffold Implants: 15-Year Study

Articular cartilage can be easily damaged from human's daily activities, leading to inflammation and to osteoarthritis, a situation that can diminish the patients' quality of life. For larger cartilage defects, scaffolds are employed to provide cells the appropriate three-dimensional environment to proliferate and differentiate into healthy cartilage tissue. Natural biomaterials used as scaffolds, attract researchers' interest because of their relative nontoxic nature, their abundance as natural products, their easy combination with other materials, and the relative easiness to establish Marketing Authorization. The last 15 years were chosen to review, document, and elucidate the developments on cell-seeded natural biomaterials for articular cartilage treatment in vivo. The parameters of the experimental designs and their results were all documented and presented. Considerations about the newly formed cartilage and the treatment of cartilage defects were discussed, along with difficulties arising when applying natural materials, research limitations, and tissue engineering approaches for hyaline cartilage regeneration.

Characterization of Chitosan Films Incorporated with Different Substances of Konjac Glucomannan, Cassava Starch, Maltodextrin and Gelatin, and Application in Mongolian Cheese Packaging

Four kinds of edible composite films based on chitosan combined with additional substances (konjac glucomannan, cassava starch, maltodextrin and gelatin) and the addition of lysozyme were prepared and used as packaging materials for Mongolian cheese. The prepared composite films were evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. The physicochemical properties of all chitosan composite films, including thickness, viscosity, opacity, color, moisture content, water vapor permeability, tensile strength and elongation at break, were measured. The results show that Konjac glucomannan–chitosan composite film presented the strongest mechanical property and highest transparency. The cassava starch–chitosan composite film presented the highest water barrier property. The study on the storage characteristics of Mongolian cheese was evaluated at 4 °C. The results show that the cheese packaging by cassava starch–chitosan composite film presented better treatment performance in maintaining the quality, reducing weight loss and delayering microbial growth.