Incorporation of graphene oxide to enhance fish gelatin as bio-packaging material

Graphene-based nanomaterials applications for agricultural and food sector

In the past decade, graphene-based nanomaterials (GBNs) have been considerably investigated in agriculture due to their exceptionally enriched physicochemical properties. Productivity in the agricultural sector relies significantly on agrochemicals. However, conventional systems suffer from a lack of application efficiency, resulting in environmental pollution and associated problems. Due to high surface area, easy functionalization, high chemical stability, biocompatibility, and ability to adhere to biological structures, GBNs become a promising candidate for agro-delivery carriers. A comprehensive review on developments of GBNs for pesticide delivery, nutrient delivery, food packaging and preservation, and their impacts on plant growth and development are missing in the literature. To address this, here we presented a detailed review on the material design, agrochemicals loading, release or diffusion kinetics, in-vivo applications, and effects of GBNs on plants. The GBNs found to improve the efficacy of existing agrochemicals and food preservatives, aiming to decrease the overall burden of these substances. The incorporation of GBNs in biocompatible and biodegradable polymers is reported to improve their oxygen barrier and mechanical properties for food packaging applications, targeting to reduce the use of petroleum-derived polymers based current food packaging materials, which leads to serious environmental impacts. In the context of plant nanobionics, GBNs has been found to boost the plant growth at low concentrations. Here, recommendations for future research have been deliberated, drawing reference from the relevant area to gain a deeper understanding of the underlying science, and to develop better delivery and packaging applications approaches. Additionally, discussions on recommendations regarding the safe concentration of GBNs for plant nanobionics are presented to facilitate their secure and effective utilization.

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.

Enhanced properties of gelatin films incorporated with TiO2-loaded reduced graphene oxide aerogel microspheres for active food packaging applications

The synergistic effect of graphene sheets and titanium dioxide nanoparticles (TiO2) hybrid fillers can improve the antibacterial, mechanical, and barrier properties of gelatin (GL), making it more suitable to be used in the food packaging application. However, the uneven dispersion and aggregation of the hybrid fillers restrict its performance for further application. In order to achieve the above superior properties, reduced graphene oxide aerogel microspheres (rGOAMs) loaded with TiO2 (rGOAMs@TiO2) were successfully prepared using one-step hydrothermal process by reducing titanium sulfate into TiO2 on the framework of rGOAMs, followed by effective dispersion in the GL matrix to form nanocomposites (rGOAMs@TiO2/GL) through simultaneous ultrasonication and mechanical stirring, as well as an ultrasonic cell grinder process. Incorporating a mere 0.8 wt% of rGOAMs@TiO2 effectively improved the mechanical, antibacterial, UV light barrier, thermal stability, hydrophobicity, and water vapor barrier properties of the GL. Compared with the composites made of rGOAMs, TiO2, and GL (rGOAMs/TiO2/GL), rGOAMs@TiO2/GL composites showed stronger filler-matrix interactions, better filler dispersion, and lower TiO2 particle aggregation, suggesting superiority compared to rGOAMs/TiO2/GL composites at the same filler content. This innovative method of mixing GL with rGOAMs@TiO2 holds great promise for enhancing the suitability of GL in active food packaging applications.

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.

Characterization of a Graphene Oxide-Reinforced Whey Hydrogel as an Eco-Friendly Absorbent for Food Packaging

This study presents a structural analysis of a whey and gelatin-based hydrogel reinforced with graphene oxide (GO) by ultraviolet and visible (UV-VIS) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results revealed barrier properties in the UV range for the reference sample (containing no graphene oxide) and the samples with minimal GO content of 0.66×10−3% and 3.33×10−3%, respectively, in the UV-VIS and near-IR range; for the samples with higher GO content, this was 6.67×10−3% and 33.33×10−3% as an effect of the introduction of GO into the hydrogel composite. The changes in the position of diffraction angles 2θ from the X-ray diffraction patterns of GO-reinforced hydrogels indicated a decrease in the distances between the turns of the protein helix structure due to the GO cross-linking effect. Transmission electron spectroscopy (TEM) was used for GO, whilst scanning electron microscopy (SEM) was used for the composite characterization. A novel technique for investigating the swelling rate was presented by performing electrical conductivity measurements, the results of which led to the identification of a potential hydrogel with sensor properties.

Bio-Nanocomposite Based on Edible Gelatin Film as Active Packaging from Clarias gariepinus Fish Skin with the Addition of Cellulose Nanocrystalline and Nanopropolis

This study develops bio-nano composite gelatin-based edible film (NEF) by combining nanogelatin, cellulose nanocrystal (CNC), and nanopropolis (NP) fillers to improve the resulting film characteristics. The NEF was characterized in terms of thickness, swelling, pH, water content, solubility, vapor and oxygen permeability, mechanical properties, heat resistance, morphology, transparency, and color. The results showed that the thickness and swelling increased significantly, whilst the pH did not significantly differ in each treatment. The water content and the water solubility also showed no significant changes with loadings of both fillers. At the same time, vapor and oxygen permeability decreased with addition of the fillers but were not significantly affected by the loading amounts. The heat resistance properties increased with the filler addition. Tensile strength and Young’s modulus increased for the films loaded with >3% CNC. The elongation at break showed a significant difference together with transparency and color change. The greater the CNC concentration and NP loading were, the darker the resulting transparency and the color of the NEF. Overall results show a considerable improvement in the properties of the resulting NEFs with the incorporation of CNC and NP fillers.

Plant protein-based nanocomposite films: A review on the used nanomaterials, characteristics, and food packaging applications

Consumer demands to utilize environmentally friendly packaging have led researchers to develop packaging materials from naturally derived resources. In recent years, plant protein-based films as a replacement for synthetic plastics have attracted the attention of the global food packaging industry due to their biodegradability and unique properties. Biopolymer-based films need a filler to show improved packaging properties. One of the latest strategies introduced to food packaging technology is the production of nanocomposite films which are multiphase materials containing a filler with at least one dimension less than 100 nm. This review provides the recent findings on plant-based protein films as biodegradable materials that can be combined with nanoparticles that are applicable to food packaging. Moreover, it investigates the characterization of nanocomposite plant-based protein films/edible coatings. It also briefly describes the application of plant-based protein nanocomposite films/coating on fruits/vegetables, meat and seafood products, and some other foods. The results indicate that the functional performance, barrier, mechanical, optical, thermal and antimicrobial properties of plant protein-based materials can be extended by incorporating nanomaterials. Recent reports provide a better understanding of how incorporating nanomaterials into plant protein-based biopolymers leads to an increase in the shelf life of food products during storage time.

Recent Applications of Biopolymers Derived from Fish Industry Waste in Food Packaging

Fish waste is attracting growing interest as a new raw material for biopolymer production in different application fields, mainly in food packaging, with significant economic and environmental advantages. This review paper summarizes the recent advances in the valorization of fish waste for the preparation of biopolymers for food packaging applications. The issues related to fishery industry waste and fish by-catch and the potential for re-using these by-products in a circular economy approach have been presented in detail. Then, all the biopolymer typologies derived from fish waste with potential applications in food packaging, such as muscle proteins, collagen, gelatin, chitin/chitosan, have been described. For each of them, the recent applications in food packaging, in the last five years, have been overviewed with an emphasis on smart packaging applications. Despite the huge industrial potential of fish industry by-products, most of the reviewed applications are still at lab-scale. Therefore, the technological challenges for a reliable exploitation and recovery of several potentially valuable molecules and the strategies to improve the barrier, mechanical and thermal performance of each kind of biopolymer have been analyzed.