Synthesis and Characterization of a Novel Composite Edible Film Based on Hydroxypropyl Methyl Cellulose Grafted with Gelatin

Sustainable and biodegradable polymer packaging: Perspectives, challenges, and opportunities

The escalating environmental impact of non-biodegradable plastic waste has intensified global efforts to seek sustainable alternatives, with biodegradable polymers from renewable sources emerging as a promising solution. This manuscript provides the current perspectives, challenges, and opportunities within the field of sustainable and biodegradable packaging. Despite a significant market presence of conventional non-biodegradable petrochemical-based plastics, there is a growing trend towards the adoption of bio-based polymers from renewable resources driven by environmental sustainability and regulatory measures. However, the transition to biodegradable packaging is fraught with challenges, including scalability, cost-effectiveness, technological limitations, comprehensive waste management systems, and infrastructural needs. The manuscript highlights the intrinsic technological challenges and the need for advancements in material science to enhance the performance and adoption of biodegradable packaging. This paper also supply insights into the development and implementation of biodegradable packaging, offering a comprehensive overview of its role in achieving global sustainability goals.

Synthesis of Carboxylate-Dialdehyde Cellulose to Use as a Component in Composite Thin Films for an Antibacterial Material in Wound Dressing

Wound infections can lead to life-threatening infection and death. Antibacterial materials from biopolymers in the form of films are a promising strategy for wound dressings. Carboxylate-dialdehyde cellulose (CDAC) is a proper candidate for use as an antibacterial material due to its biocompatibility, nontoxicity, and antibacterial property. Additionally, CDAC can be synthesized from cellulose through environmentally friendly and nontoxic methods. Thus, this study aims to synthesize CDAC from microcrystalline cellulose (MCC) PH102 and use it in composite films for an antibacterial application. The CDAC was synthesized using Fe2+/H2O2, followed by NaIO4 oxidation. The obtained CDAC was characterized in terms of carboxylate and aldehyde content as well as FTIR and XRD spectra. The CDAC was mixed with HPMC in different ratios to prepare films. To determine the optimal formulation for clindamycin HCl loading, the films were evaluated for morphology, mechanical properties, and swelling ratio. Finally, the films containing clindamycin HCl were evaluated for drug loading content, in vitro drug release, and antibacterial activity. This study found that CDAC contained 2.1 ± 0.2 carboxylate and 4.15 ± 0.2 mmol/g of aldehyde content. The FTIR spectra confirmed the successful synthesis. X-ray diffractograms indicated that CDAC was less crystalline than MCC. The film, consisting of CDAC and HPMC E50 in the ratio of 2:1 (D2H1), was identified as the most suitable for clindamycin HCl loading due to its superior appearance, mechanical strength, and swelling properties compared to other formulations. D2H1 exhibited a high drug loading capacity (91.49 ± 5.48%) and demonstrated faster drug release than the film composed only of HPMC because of the higher swelling ratio and lower mechanical strength. This formulation was effective against Staphylococcus aureus (MSSA), S. aureus (MRSA), and Pseudomonas aeruginosa. Furthermore, the D2H1 film containing clindamycin HCl showed a larger inhibition zone against these bacteria, likely due to a synergistic effect. This study found that CDAC has the potential to be applied as an antibacterial material for wound dressing.

Advances in biomaterials based food packaging systems: Current status and the way forward

World hunger is getting worse, while one-third of food produced around the globe is wasted and never consumed. It is vital to reduce food waste to promote the sustainability of food systems, and improved food packaging solutions can augment this effort. The utilization of biomaterials in smart food packaging not only enhances food preservation and safety but also aligns with current demands for eco-friendly technologies to mitigate the impacts of climate change. This review provides a comprehensive overview of the developments in the field of food packaging based on the innovative use of biomaterials. It emphasizes the potential use of biomaterials derived from nature including cellulose, chitosan, keratin, etc. for this purpose. Various smart food packaging technologies such as active and intelligent packaging are discussed in detail including scavenging additives, colour-changing environment indicators, sensors, RFID tags, etc. The article also delves into the utilization of edible films and coatings, nanoparticle fillers and 2D materials in food packaging systems. Furthermore, it outlines the challenges and opportunities in this dynamic domain, emphasizing the ongoing need for research and innovation to shape the future of sustainable and smart food packaging solutions to enhance and monitor the shelf-life of food products.

Strategies for the incorporation of organosolv lignin in hydroxypropyl methylcellulose-based films: A comparative study

Organosolv lignin extracted from vine pruning residues was added to hydroxypropyl methylcellulose (HPMC)-based films using three strategies: i) lignin incorporated into the film (lignin-based film), ii) lignin nanoparticles (LNPs) incorporated into the film (LNPs-based film), and iii) lignin coated on HPMC films' surface (lignin-coated film). The films obtained were evaluated in terms of morphology, water barrier and mechanical properties, and antioxidant capacity. Results showed that LNPs incorporation did not affect the films´ water vapour permeability (WVP). Nonetheless, the lignin-based and lignin-coated films improved the water barrier properties of HPMC-based films, achieving a 31.5 and 36 % reduction of WVP, respectively. The morphological evaluation, performed by scanning electron microscopy, revealed films' morphology changes with the lignin incorporation, which was more evident in the lignin-based films. Fourier transform infrared spectroscopy (FTIR) showed minor changes in the film's structure using the different lignin incorporation methods. The mechanical properties were improved, including a significant increase in the tensile strength in the lignin-based and lignin-coated films. All films showed high radical scavenging activity (RSA) after 24 h, with a gradual increase in the lignin-coated films over time. The lignin-coated films showed to be the most promising incorporation strategy to improve the HPMC-based film's properties.

Physical Properties of Cellulose Derivative-Based Edible Films Elaborated with Liposomes Encapsulating Grape Seed Tannins

Combined use of edible films (EF) with nanoencapsulation systems could be an effective alternative for improving the films' physical properties and maintaining bioactive compounds' stability. This research work focuses on the combined use of EF of cellulose-derived biopolymers enriched with liposomes that encapsulate grape seed tannins and on the subsequent evaluation of the physical properties and wettability. Tannin-containing liposomal suspensions (TLS) showed 570.8 ± 6.0 nm particle size and 99% encapsulation efficiency. In vitro studies showed that the release of tannins from liposomes was slower than that of free tannins, reaching a maximum release of catechin of 0.13 ± 0.01%, epicatechin of 0.57 ± 0.01%, and gallic acid of 3.90 ± 0.001% over a 144 h period. Adding liposomes to biopolymer matrices resulted in significant decrease (p < 0.05) of density, surface tension, tensile strength, elongation percentage, and elastic modulus in comparison to the control, obtaining films with greater flexibility and lower breaking strength. Incorporating TLS into EF formulations resulted in partially wetting the hydrophobic surface, reducing adhesion and cohesion compared to EF without liposomes. Results indicate that the presence of liposomes improves films' physical and wettability properties, causing them to extend and not contract when applied to hydrophobic food surfaces.

The application of film based on gelatin/hydroxymethyl cellulose and red beetroot betalain in smart food packaging

Edible films containing anthocyanin and betacyanin as indicators of freshness are promising systems for food smart packaging. This research aimed to develop a smart color film for food packaging using gelatin/hydroxypropylmethyl cellulose (HPMC) and red beet betalain. In this study, edible films with different ratios of gelatin to HPMC were prepared successfully, and the ratio of 3:1 was determined as optimal samples based on water vapor permeability (WVP) and mechanical properties. Betalain with different concentrations was then added to the optimal film, and the physical and mechanical properties of the resulting films were evaluated. Also, TVB-N test to assess their ability to detect beef meat and shrimp spoilage was studied. The addition of betalain improved the solubility, WVP, mechanical properties, and 2,2-diphenyl-l-picrylhydrazyl free radical scavenging activity of the film. As a final point, the incorporation of betalain into the gelatin/HPMC films can be used to indicate the freshness of food.

Synthesis and characterization of polysaccharide- and protein-based edible films and application as packaging materials for fresh fish fillets

The rising packaging industry together with global demand for sustainable production has increased the interest in developing biodegradable packaging materials. The aim of the study was to develop edible films based on pectin, gelatin, and hydroxypropyl methylcellulose and evaluate their applicability as biodegradable packaging materials for gilthead seabream fillets. Mechanical properties, water barriers, wettability of the films through contact angle measurement, optical, and UV-Vis barrier properties were evaluated for food packaging applications. The effective blend of polysaccharide and protein film-forming solutions was confirmed by the produced films with excellent optical properties, acceptable mechanical properties and adequate barriers to water vapor. The contact angle for pectin based and gelatin based films were higher than 90° indicating the hydrophobic films, while HPMC based films had contact angle lower than 90°. The produced films were tested as alternative and environmentally friendly packaging materials for gilthead seabream fillets during refrigerated storage. All tested packaging conditions resulted in similar shelf-life in packed gilthead seabream fillets (i.e. 7-8 days at 2 °C). The results showed that the developed films may reduce the use of conventional petroleum-based food packaging materials without affecting the shelf-life of fish.

Mechanical and Surface Properties of Edible Coatings Elaborated with Nanoliposomes Encapsulating Grape Seed Tannins and Polysaccharides

Edible composite coatings (ECC) formulated from biopolymers that incorporate antioxidant molecules represent an innovative alternative to improve food texture and provide health benefits. Tannins have aroused great interest due to their ability to stabilize suspensions and counteract the effects of free radicals. The mechanical and surface properties are crucial to establishing its quality and applicability. In this study, the objective was to analyze the mechanical and surface properties of ECC made with nanoliposomes that encapsulate grape seed tannins (TLS) and polysaccharides such as hydroxypropylmethylcellulose (HPMC) and kappa carrageenan (KCG) for their future direct application in foods susceptible to oxidation. The inclusion of HPMC or KCG affected the density, showing values in the range of 1010 to 1050 [kg/m3], evidencing significant changes (p < 0.05) in the surface tension in the TLS/FS-HPMC and TLS/FS mixtures. KCG and in the dispersion coefficients, with values in the range of -2.9 to -17.6 [mN/m] in HPS (S1) and -17.6 to -40.9 [mN/m] in PDMS (S2). The TLS/FS-HPMC coating showed higher stiffness and elastic recovery capacity than the TLS/FS-KCG coating, suggesting that the presence of TLS influenced the stiffness of the polymer. HPMC is recommended as a suitable polymer for coating solids, while KCG is more appropriate for suspensions. These findings provide valuable information for directly applying these ECC compounds to food products, potentially offering better preservation and health benefits.