Active and Robust Composite Films Based on Gelatin and Gallic Acid Integrated with Microfibrillated Cellulose

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.

Characterization of Fibers Prepared by Centrifugal Spinning from Biotechnologically Derived Chicken Gelatin

The application of biopolymer-based materials is increasing due to better sustainability and environmental protection properties. Gelatin fibers have a specific surface and high porosity, which is why their use in medicine and the food industry is being researched. This article explores the potential of centrifugal spinning to produce gelatin fibers. Gelatin for fiber preparation was obtained from a non-traditional source of collagen (chicken by-products) using a unique enzymatic process. The fiber quality was compared with those prepared from gelatins produced from traditional collagen tissues (porcine, bovine). The results showed that fibers cross-linked with glutaraldehyde vapor preserved their structure even in contact with water. Using a cross-linker controlled swelling ability and solubility while maintaining the fiber structure. On the contrary, uncross-linked gelatin fibers were water soluble due to a high surface-to-volume ratio, facilitating water penetration and dissolution. Scanning electron microscopy (SEM) provided a clearer picture of the morphology of gelatin fibers obtained by centrifugal spinning. Differences in the amount of bonding depending on the raw material used and the presence of a cross-linker were analyzed using Fourier transform infrared spectroscopy (FTIR). The overall results showed that chicken gelatin is a suitable alternative to gelatins from traditional sources and can be used for preparing food and pharmaceutical packaging and coatings, fibers, or bioprinting of 3D matrices.

Assessing anticancer, antidiabetic, and antioxidant capacities in green-synthesized zinc oxide nanoparticles and solvent-based plant extracts

Cancer and diabetes represent significant challenges in the field of biomedicine, with major and global impacts on public health. Acacia nilotica, commonly called 'gum arabic tree,' is recognized for its unique biomedical properties. The current study aimed to investigate the pharmacological potential of A. nilotica-based zinc-oxide nanoparticles (ZnO-NPs) in comparison to the ethanol and methanol-based extracts against cancer, diabetes, and oxidative stress. Green synthesis of ZnO-NPs was performed using barks of Acacia nilotica. Different techniques for the characterization of ZnO-NPs, including UV-Visible spectroscopy, Scanning Electron Microscopy, Fourier Transmission Infrared (FT-IR) spectroscopy, and X-ray Diffraction (XRD), were utilized. The morphological analysis of ZnO-NPs revealed that the fine NPs have mean particle sizes of 15 ± 1.5 nm. For the solvent based-extraction, leaves and barks were utilized and dissolved into ethanol and methanol for further processing. The MTT assay revealed that the optimum concentration of ZnO-NPs to inhibit the proliferation of liver cancer cell line HepG2 was 100 μg/mL where 67.0 % inhibition was observed; and both ethanol- and methanol-based extracts showed optimum inhibition at 100 μg/mL. The DPPH assay further demonstrated that 250 μg/mL of ZnO-NPs and 1000 μg/mL of both ethanol- and methanol-based extracts, as the optimum concentration for antioxidant activity (with 73.1 %, 68.9 % and 68.2 % inhibition respectively). The α-Glucosidase inhibition assay revealed that 250 μg/mL of ZnO-NPs and 10 μg/mL of both ethanol- and methanol-based extracts as the optimum concentration for antidiabetic activity (with 95 %, 93.7 % and 93.4 % inhibition respectively). The study provided interesting insights into the efficacy and reliability of ZnO-NPs for potential pharmacological application. Further research should be focused on examining specific pathways and the safety of ZnO-NPs in comparison to solvent-based extracts.

Morphological Characteristics of Biopolymer Thin Films Swollen-Rich in Solvent Vapors

Biopolymers exhibit a large variety of attractive properties including biocompatibility, flexibility, gelation ability, and low cost. Therefore, especially in more recent years, they have become highly suitable for a wider and wider range of applications stretching across several key sectors such as those related to food packaging, pharmaceutic, and medical industries, just to name a few. Moreover, biopolymers' properties are known to be strongly dependent on the molecular arrangements adopted by such chains at the nanoscale and microscale. Fortunately, these arrangements can be altered and eventually optimized through a plethora of more or less efficient polymer processing methods. Here, we used a space-confined solvent vapor annealing (C-SVA) method to subject various biopolymers to rich swelling in solvent vapors in order to favor their further crystallization or self-assembly, with the final aim of obtaining thin biopolymer films exhibiting more ordered chain conformations. The results obtained by atomic force microscopy revealed that while the gelatin biopolymer nucleated and then crystallized into granular compact structures, other biopolymers preferred to self-assemble into (curved) lamellar rows composed of spherical nanoparticles (glycogen and chitosan) or into more complex helix-resembling morphologies (phytagel). The capability of the C-SVA processing method to favor crystallization and to induce self-assembly in various biopolymeric species or even monomeric units further emphasizes its great potential in the future structuring of a variety of biological (macro)molecules.

Eco-friendly cellulose-based antioxidation film by partial esterification

Cellulose nanocrystals (CNCs) have received increasing attention because of their superior dispersion and thermal stability. In this study, TEMPO-oxidized cellulose nanocrystal (TOCNC) multifunctional antioxidationantioxidation films (TOCNC-GA film) were prepared by the esterification of TOCNC and gallic acid (GA). TOCNC-GAX films, where X represents the ratio of the amount of GA to the amount of TOCNC, were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The films with the GA:TOCNC ratio of 1:1 achieved higher interfacial compatibility than the other films. The mechanical properties and water resistance of the TOCNC-GA films were superior than those of pure TOCNC films. Moreover, the original TOCNC structure changed owing to the presence of GA, which endowed a certain thermoplasticity owing to the formation of ester groups. The antioxidation properties of the TOCNC-GA1 films reached 43.8 % and 71.85 % after 6 and 24 h, respectively, as evaluated by the 2,2-biphenyl-1-picrylhydrazyl method and the free radical scavenging activities of the TOCNC-GA1 films. The innovative development of the functional antioxidation film presented in this paper has great potential for use in antioxidation packaging materials and food preservation.

Preparation and performance testing of corn starch/pullulan/gallic acid multicomponent composite films for active food packaging

The present study investigated the mechanical characteristics, hydrophobicity, antioxidant and antibacterial properties, FTIR, SEM and XRD of films fabricated with corn starch and pullulan (CS/PUL) by adding different concentrations of Gallic acid (GA) (0%, 0.5%, 1.0%, 1.5% w/v). The mechanical strength and opacity of CS/PUL films were enhanced by the addition of 1.0% GA. The water vapor permeability (WVP) of CS/PUL films was significantly lower in films with GA compared to those without (P < 0.05). The addition of GA, especially at concentrations of 1.0% and 1.5%, resulted in considerably better free radical scavenging activities on DPPH than films without GA (P < 0.05). Interestingly, the highest water contact angle (WCA) value was observed in films with 0.5% GA, indicating stronger hydrophobicity. Furthermore, the antibacterial capabilities of the films, particularly against E. coli and P. aeruginosa, improved with an increase in GA concentration. The results of FTIR, SEM and XRD analyses showed that GA was well distributed in the CS/PUL matrix.

Fabrication, performance, and potential environmental impacts of polysaccharide-based food packaging materials incorporated with phytochemicals: A review

Although food packaging preserves food's quality, it unfortunately contributes to global climate change since the considerable carbon emissions associated with its entire life cycle. Polysaccharide-based packaging materials (PPMs) are promising options to preserve foods, potentially helping the food industry reduce its carbon footprint. PPMs incorporated with phytochemicals hold promise to address this critical issue, keep food fresh and prolong the shelf life. However, phytochemicals' health benefits are impacted by their distinct chemical structures thus the phytochemicals-incorporated PPMs generally exhibit differential performances. PPMs must be thoughtfully formulated to possess adequate physicochemical properties to meet commercial standards. Given this, this review first-time provides a comprehensive review of recent advances in the fabrication of phytochemicals incorporated PPMs. The application performances of phytochemicals-incorporated PPMs for preserving foods, as well as the intelligent monitoring of food quality, are thoroughly introduced. The possible associated environmental impacts and scalability challenges for the commercial application of these PPMs are also methodically assessed. This review seeks to provide comprehensive insights into exploring new avenues to achieve a greener and safer food industry via innovative food packaging materials. This is paramount to preserve not only food shelf life but also the environment, facilitating the eco-friendly development of the food industry.

Use of cellulose microfibers from olive pomace to reinforce green composites for sustainable packaging applications

To valorize abundant, unexploited, and low-cost agro-industrial by-products, olive pomace is proposed as a sustainable and renewable raw material for cellulose microfibers (CMFs) production. In this study, CMFs were extracted from olive pomace using alkaline and bleaching treatments and characterized in terms of morphological, structural, and thermal properties. Afterward, the reinforcing capability of microfibers was examined using carboxymethyl cellulose (CMC) as a polymer matrix by the solvent casting process. The effects of CMF loading (1%, 3%, 5%, and 10%) on the composites' mechanical, physical, morphological, and thermal properties were assessed. CMF incorporation led to a decrease in moisture content (MC), water solubility (WS), and water vapor permeability (WVP) and an increase in tensile strength (TS), stiffness and transparency values, and thermal stability of CMC films. Increasing CMF content to 5%, increased the TS and elasticity modulus by 54% and 79%, respectively, and reduced the WVP and light transmissivity at 280 nm, by 22% and 47%, respectively. The highest water, moisture, light barrier, and mechanical properties of composites were reached at 5% CMFs.

Morphology and Rheology of a Cool-Gel (Protein) Blended with a Thermo-Gel (Hydroxypropyl Methylcellulose)

This study investigates the morphological and rheological properties of blended gelatin (GA; a cooling-induced gel (cool-gel)) and hydroxypropyl methylcellulose (HPMC; a heating-induced gel (thermo-gel)) systems using a fluorescence microscope, small angle X-ray scattering (SAXS), and a rheometer. The results clearly indicate that the two biopolymers are immiscible and have low compatibility. Moreover, the rheological behavior and morphology of the GA/HPMC blends significantly depend on the blending ratio and concentration. Higher polysaccharide contents decrease the gelling temperature and improve the gel viscoelasticity character of GA/HPMC blended gels. The SAXS results reveal that the correlation length (ξ) of the blended gels decreases from 5.16 to 1.89 nm as the HPMC concentration increases from 1 to 6%, which suggests that much denser networks are formed in blended gels with higher HPMC concentrations. Overall, the data reported herein indicate that the gel properties of gelatin can be enhanced by blending with a heating-induced gel.