Cellulose Nanofibers from Olive Tree Pruning as Food Packaging Additive of a Biodegradable Film

Nanocellulose hydrogels from agricultural wastes: methods, properties, and application prospects

Escalating environmental concerns and the depletion of non-renewable resources have intensified interest in sustainable and eco-friendly materials. Cellulose-based hydrogels, renowned for their biocompatibility, biodegradability, and excellent mechanical properties, have emerged as promising candidates for diverse applications, including biomedicine, agriculture, and water purification. This review focuses on methods for extracting nanocellulose from agricultural wastes and their use in creating cellulose hydrogels. Special emphasis is placed on the mechanical, chemical, thermal, and environmental properties of nanocellulose, as well as its applications in packaging materials, medical devices, biocomposites, and filtration systems. The literature review examines cellulose extraction methods, hydrogel properties, and their industrial applications. The key advantages and disadvantages of these methods are identified, and directions for future research are proposed. This work provides a comprehensive overview of the current state of research on cellulose-based hydrogels and contributes to the development of more efficient and sustainable production methods for these materials.

Ginger residue-derived nanocellulose as a sustainable reinforcing agent for composite films

Nanocellulose extracted from agricultural waste for the development of reinforced sustainable composites is needed, due to a greater environmental responsibility and awareness of environmental pollution. In this work, the extraction of nanocellulose (GNC) from ginger residue was conducted via acid hydrolysis without complicated pretreatments. The potential application of GNC as a reinforcing agent for sustainable composite films was also explored. The results showed that the obtained GNC exhibited a rod-like shape with a high aspect ratio (15.75 ± 4.25). X-ray diffraction patterns revealed a cellulose II structure with a crystallinity index of 88.47 %. The reinforcing effects of GNC were evaluated in composite films made from different matrices, including sodium alginate (SA) and chitosan (CS), to assess its performance in enhancing material properties. The incorporation of 5 % of GNC significantly improved the tensile strength of SA and CS by 94 % and 64 %, respectively. Notably, the addition of GNC also enhanced the elongation at break of the SA-based films. This study demonstrates that ginger residue is a promising and sustainable feedstock for extracting nanocellulose, which can serve as an effective reinforcing agent in biocomposite films.

A sustainable approach to develop antimicrobial composite film incorporating novel Dalbergia reniformis seed-derived microcrystalline cellulose and medicinal Mikania micrantha extract in PVA

This study presents a sustainable approach to develop antimicrobial films (AMFs) using agricultural wastes. Microcrystalline cellulose (MCC) was extracted from a novel source of Dalbergia reniformis seeds (DRS) through chemical hydrolysis, and bioactive powder from Mikania micrantha (MM) leaves was reinforced into a polyvinyl alcohol (PVA) matrix to create antimicrobial films. The morphological, antimicrobial, physical, mechanical, and thermal properties of the films were investigated. MCC (5 %, 10 %, and 15 %) and MM (5 % and 10 %) concentrations were varied to study their effects on film properties. Fourier transform infrared spectroscopy confirmed the elimination of non-cellulosic compounds in MCC and the chemical interactions among film components, while X-ray diffraction analysis revealed improved crystallinity of MCC compared to raw pulp and enhanced crystallinity of AMFs compared to pure PVA. Scanning electron microscopic images demonstrated better adhesion and homogeneous MCC distribution in the PVA matrix up to a concentration 10 % MCC, while higher concentrations caused self-aggregation. The AMFs showed strong antibacterial activity, with inhibition zones of 18.83 mm for S. aureus and 18.55 mm for E. coli at 10 % MM. Anti-inflammatory properties were confirmed, with pure MM reducing swelling by 46.8 % and AMFs with 10 % MM achieving 33.9 % inhibition. Mechanical properties, including tensile strength, increased by 57.7 % with 10 % MCC but declined at 15 % MCC due to aggregation. Conversely, the moisture content, water solubility, and water vapor permeability of the films significantly decreased with up to 10 % MCC. These findings highlight the potential of the developed AMFs for antimicrobial applications in healthcare, food packaging, and other industries.

Enhancing circular bioeconomy: Alginate-cellulose nanofibre films/coatings functionalized with encapsulated pomegranate peel extract for postharvest preservation of pomegranate arils

This study investigated the properties of alginate-cellulose nanofiber (AL-CNF) bio-composite coatings functionalized with pomegranate peel extract powder (PPEP) at 0.1, 0.3, and 0.5 % (w/v) and their effects on the postharvest shelf life of pomegranate arils stored at 5 °C and 95 ± 2 % RH for 15 days. The results demonstrated that PPEP incorporation enhanced the physical, functional, and antioxidant properties of the coatings while reducing their mechanical strength. Microstructural analysis revealed that CNF contributed to a rougher surface, whereas PPEP addition improved homogeneity and smoothness. The 0.5 % PPEP concentration exhibited the highest thickness, antioxidant activity, and phenolic content. Application of AL-CNF bio-composite coatings significantly (p < 0.05) reduced weight loss, delayed respiration, and maintained firmness compared to the control. PPEP incorporation increased total soluble solids (TSS) and preserved the visual quality of arils. Additionally, 0.5 % PPEP retained higher phenolic content, anthocyanin levels, and DPPH activity while reducing microbial growth. These findings suggest that AL-CNF nanocomposite coatings enriched with PPEP (0.1-0.5 %) effectively preserve quality and extend the shelf life of minimally processed pomegranate arils, offering a sustainable postharvest preservation strategy.

(Ligno)Cellulose Nanofibrils and Tannic Acid as Green Fillers for the Production of Poly(vinyl alcohol) Biocomposite Films

This study compared the use of cellulose nanofibrils (CNF) and lignocellulose nanofibrils (LCNF) in different concentrations to reinforce the poly(vinyl alcohol) (PVA) matrix. Both nanofillers significantly improved the elastic modulus and tensile strength of PVA biocomposite films. The optimum concentration of CNF and LCNF was 6% relative to PVA, which improved the tensile strength of the final PVA biocomposite with CNF and LCNF by 53% and 39%, respectively, compared to the neat PVA film. The addition of LCNF resulted in more elastic films than the addition of CNF to the PVA matrix. The elongation at break of the PVA biocomposite with 2% of LCNF was more than 100% higher than that of the neat PVA film. The integration of tannic acid (TA) into the PVA-LCNF system resulted in antioxidant-active and more water-resistant PVA biocomposites. The three-component biocomposite films with 2 and 6% LCNF and 10% TA exhibited a more than 20° higher contact angle of the water droplet on the surfaces of the biocomposite films and absorbed more than 50% less water than the neat PVA film. New formulations of biocomposite films have been developed with the addition of LCNF and TA in a polymeric PVA matrix.

Olive pomace upcycling: Eco-friendly production of cellulose nanofibers by enzymatic hydrolysis and application in starch films

Olive pomace (OP) waste, produced in large quantities, contains significant amounts of cellulose and fibers, making it a valuable resource for developing reinforcing ingredients in biodegradable packaging materials. This study aimed to produce nanofibers from OP using enzymatic hydrolysis with hemicellulases and cellulases, and to incorporate these nanofibers into starch films as a reinforcing agent. Cellulose nanofibers (CNFs) were prepared by alkaline pretreatment followed by enzymatic hydrolysis (with hemicellulases and cellulases) from olive pomace and applied as reinforcement in starch films in concentrations of 0.5%-5% (w/v). The nanofibers were analyzed according to composition, structural, and thermal properties. The nanofibers' suspension presented a cloudy and white color in aqueous suspension, the X-ray diffraction (XRD) analysis showed the increase of crystallinity, and the fibers' range was no wider than 100 nm (according to Scherer equation). The composition analysis showed the decrease of carbonyl groups of hemicellulose and lignin. The starch films presented a homogenous surface. The solubility from these biodegradable films significantly reduced after the incorporation of CNF, and the nanomaterial's presence improved the degradation temperature (from 310°C to 322°C) and the mechanical resistance because the tension of rupture increased from 3.79 to 6.21 MPa. PRACTICAL APPLICATION: The utilization of waste from the olive pomace for cellulose nanofiber production holds promise, given the nanofibers' ability to readily integrate into various materials, including starches used in biodegradable film production. Within these matrices, nanofibers act as structure reinforcers and significantly reduce the solubility of films. Although biodegradable films ensure the shelf life, safety, and quality of food, their properties currently do not match those of traditional petroleum-based materials at an industrial scale, indicating a need for further enhancement.

Cellulose synthesis from germinated tiger nut residue and its application in the production of a functional cookie

In this study, cellulose was synthesized from the residue obtained after germinating tiger nuts for 0, 48, 72 or 96 h. The influence of the synthesized cellulose (0%, 2%, or 5%) on the quality of clove extract laden-cookies was evaluated. The optimum structure, morphology, and thermal properties of cellulose were obtained after geminating tiger nuts for 72 h. Adding cellulose to the dough stabilized the total phenolic, flavonoid, and protein contents and radical scavenging activity during the baking operation. The addition of 2% cellulose generally enhanced the hydration, pasting, and viscoelastic properties of the dough. However, 5% cellulose negatively affected the highlighted properties, culminating in poorer textural and sensory properties of the cookies produced therefrom. Germination could be effective in modifying the properties of cellulose from tiger nuts; thus, enhancing its application in the production of a functional cookie.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05972-8.

Water-resistant and barrier properties of poly(vinyl alcohol)/nanocellulose films enhanced by metal ion crosslinking

Polyvinyl alcohol (PVA) is a promising alternative to non-biodegradable flexible packaging materials, and nanocellulose is often used to enhance the properties of PVA films, but the composite films still have poor water resistance and barrier properties. To address this issue, iron ions (Fe3+) were introduced into PVA/cellulose nanofibrils (CNF) films, and Fe3+ formed coordination bonds with carboxyl and hydroxyl groups on the surface of CNF and PVA chains. Therefore, constructing a strong coordination crosslinking network within the film and improving the interfacial interaction between PVA and CNF. The water resistance, mechanical and barrier properties of the crosslinked films were significantly improved. Compared with the un-crosslinked film, the oxygen transmission rate (OTR) was decreased by up to 67 %, and the water swelling ratio was significantly reduced from 1085 % to 352 %. The tensile strength of the film with 1.5 wt% Fe3+ reached 41.93 MPa, which was 62 % higher than that of the un-crosslinked film. Furthermore, the composite film demonstrated good recyclability, almost recovering its original mechanical properties in two recycling tests. This simple and effective method for preparing water resistance and barrier films shows potential applications in flexible packaging areas.

Bioadhesive Polymeric Films Containing Rhamnolipids, An Innovative Antimicrobial Topical Formulation

Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62 µg/mL, CBM of 31.25 µg/mL and CC50 of 181.93 µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.

Nanofillers in Novel Food Packaging Systems and Their Toxicity Issues

Background: Environmental concerns about petroleum-based plastic packaging materials and the growing demand for food have inspired researchers and the food industry to develop food packaging with better food preservation and biodegradability. Nanocomposites consisting of nanofillers, and synthetic/biopolymers can be applied to improve the physiochemical and antimicrobial properties and sustainability of food packaging. Scope and approach: This review summarized the recent advances in nanofiller and their applications in improved food packaging systems (e.g., nanoclay, carbon nanotubes), active food packaging (e.g., silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs)), intelligent food packaging, and degradable packaging (e.g., titanium dioxide nanoparticles (e.g., TiO2 NPs)). Additionally, the migration processes and related assessment methods for nanofillers were considered, as well as the use of nanofillers to reduce migration. The potential cytotoxicity and ecotoxicity of nanofillers were also reviewed. Key findings: The incorporation of nanofillers may increase Young's modulus (YM) while decreasing the elongation at break (EAB) (y = -1.55x + 1.38, R2 = 0.128, r = -0.358, p = 0.018) and decreasing the water vapor (WVP) and oxygen permeability (OP) (y = 0.30x - 0.57, R2 = 0.039, r = 0.197, p = 0.065). Meanwhile, the addition of metal-based NPs could also extend the shelf-life of food products by lowering lipid oxidation by an average of approx. 350.74% and weight loss by approx. 28.39% during the longest storage period, and significantly increasing antibacterial efficacy against S. aureus compared to the neat polymer films (p = 0.034). Moreover, the migration process of nanofillers may be negligible but still requires further research. Additionally, the ecotoxicity of nanofillers is unclear, as the final distribution of nanocomposites in the environment is unknown. Conclusions: Nanotechnology helps to overcome the challenges associated with traditional packaging materials. Strong regulatory frameworks and safety standards are needed to ensure the appropriate use of nanocomposites. There is also a need to explore how to realize the economic and technical requirements for large-scale implementation of nanocomposite technologies.

TEMPO-Oxidized Nanocellulose Films Modified by Tea Saponin Derived from Camellia oleifera: Physicochemical, Mechanical, and Antibacterial Properties

Nanocellulose materials have been widely used in biomedicine, food packaging, aerospace, composite material, and other fields. In this work, cellulose obtained from Camellia shells through alkali boiling and subbleaching was micro-dissolved and regenerated using the DMAc (N,N-Dimethylacetamide)/LiCl system, and TOCNs (TEMPO-oxidized cellulose nanofibers) with different degrees of oxidation. The membrane was prepared by filtration of polytetrafluoroethylene (pore size 0.1 μm), and the oxidized nanocellulose film was obtained after drying, Then, the crystallinity, mechanical properties and oxygen barrier properties of the TOCN film were investigated. Furthermore, based on TS (tea saponin) from Camellia oleifera seed cake and TOCNs, TS-TOCN film was prepared by the heterogeneous reaction. The TS-TOCN film not only shows excellent oxygen barrier properties (the oxygen permeability is 2.88 cc·m-2·d-1) but also has good antibacterial effects on both Gram-negative and Gram-positive bacteria. The antibacterial property is comparable to ZnO-TOCN with the same antibacterial content prepared by the in-situ deposition method. Antioxidant activity tests in vitro showed that TS-TOCN had a significant scavenging effect on DPPH (2,2-Diphenyl-1-picrylhydrazyl) radicals. This design strategy makes it possible for inexpensive and abundant Camellia oleifera remainders to be widely used in the field of biobased materials.

Unlocking sustainable solutions: Nanocellulose innovations for enhancing the shelf life of fruits and vegetables - A comprehensive review

Regarding food security and waste reduction, preserving fruits and vegetables is a vital problem. This comprehensive study examines the innovative potential of coatings and packaging made of nanocellulose to extend the shelf life of perishable foods. The distinctive merits of nanocellulose, which is prepared from renewable sources, include exceptional gas barrier performance, moisture retention, and antibacterial activity. As a result of these merits, it is a good option for reducing food spoilage factors such as oxidation, desiccation, and microbiological contamination. Nanocellulose not only enhances food preservation but also complies with industry-wide environmental objectives. This review explores the many facets of nanocellulose technology, from its essential characteristics to its use in the preservation of fruits and vegetables. Furthermore, it deals with vital issues including scalability, cost-effectiveness, and regulatory constraints. While the use of nanocellulose in food preservation offers fascinating potential, it also wants to be cautiously careful to assure affordability, effectiveness, and safety. To fully use the potential of nanocellulose and advance the sustainability plan in the food business, collaboration between scientists, regulatory bodies, and industry stakeholders is important as we stand on the cusp of a revolutionary era in food preservation.

Olive mill wastes: from wastes to resources

Olive oil extraction has recently experienced a continuous increase due to its related beneficial properties. Consequently, large amounts of olive mill wastes (OMWs) derived from the trituration process are annually produced, causing serious environmental problems. The limited financial capabilities of olive mills make them usually unable to bear the high costs required for the disposal of their wastes. Alternatively, the valorization of OMWs within the framework of the so-called waste-to-resource concept and their recycling can represent a successful strategy for the implementation of circular economy model in the olive industry, which could have significant socioeconomic impacts on low-income Mediterranean countries. There is, however, no unique solution for OMWs valorization, due to the wide variety of the wastes' composition and their seasonal production. In this review, the potential of OMWs for being reused and the recent technological advances in the field of OMWs valorization are assessed. Special focus is given to the analysis of the advantages and limitations of each technology and to reporting the most significant issues that still limiting its industrial scale-up. The information collected in this review shows that OMW could be effectively exploited in several sectors, including energy production and agriculture. OMWs potential seems, however, undervalued, and the implementation of sustainable valorization strategies in large-scale remains challenging. More efforts and policy actions, through collective actions, encouraging subsidies, and establishing public-private collaborations, are still needed to reconcile research progress with industrial practices and encourage the large-scale implementation of the waste-to-resource concept in the olive sector.

Construction of multiple crosslinked networks for the preparation of high-performance lignin-containing cellulose nanofiber reinforced polyvinyl alcohol films

Polyvinyl alcohol (PVA) film, a promising alternative to non-biodegradable plastic packaging films for food and medical packaging, is limited by poor water resistance. In this work, a simple solvent evaporation self-assembly was used to construct a nanophase separation structure to establish dense interfacial hydrogen bonding, covalent bonding and iron metal ion coordination interactions between lignin-containing cellulose nanofibers (LCNFs) and PVA matrix to improve the interfacial force and solve the problem of poor compatibility of LCNFs in PVA. The iron ion (Fe3+) coordination tended to combine with the more active lignin phenolic hydroxyl group to construct the nanophase separation structure. Covalent crosslinking of glutaraldehyde (GA) improved the interfacial compatibility of PVA/LCNF films, enhanced the interfacial bonding and formed a homogeneous structure. The multi-nanophase structures improved the strength and elastic modulus of the PVA/LCNF film and provided the films with extremely low water absorption, water vapor transmission rate and excellent UV-shielding. Compared with pure PVA film, PVA-10L-5Fe-3GA film had about 106.9 % higher tensile strength, 93.9 % lower water absorption and 93.4 % lower mass loss, 69.8 % lower water vapor transmission coefficient, and was able to shield UV at 200-400 nm, which is highly expected to be used in packaging films.

Integration of wood-based components - Cellulose nanofibrils and tannic acid - into a poly(vinyl alcohol) matrix to improve functional properties

Poly(vinyl alcohol) (PVA) biocomposite films reinforced with cellulose nanofibrils (CNF) and biologically active tannic acid (TA) were prepared. The influence of different concentrations of CNF and TA in the PVA polymer matrix was investigated in terms of mechanical properties, thermal properties and hydrophobicity improvement of the prepared films. The results showed that in all cases the addition of CNF and TA improved the values of tensile strength and elastic modulus. The PVA film with 10 % CNF exhibited a 30 % higher tensile strength, and the three-component PVA film with 2 % CNF and 10 % TA (P2C10T) exhibited a 40 % higher tensile strength compared to the neat PVA film. The thermal properties (Tg, Tonset) of the PVA biocomposite films were greatly improved, with a significant effect observed for the three-component PVA films. The Tg of the PVA film with 10 % CNF and 10 % TA was 87 °C, 12 °C higher than that of the neat PVA film. For three-component PVA biocomposites with 4 % and 6 % CNF and with all weight percentages of TA, the Tonset shifted to a higher temperature range by about 30 °C compared to the neat PVA film. The PVA film with 2 % CNF and 10 % TA exhibited about a 20° higher contact angle than the neat PVA film. Moreover, the addition of both fillers to the PVA matrix resulted in PVA biocomposites with lower water absorption. PVA film with 10 % TA absorbed about 90 % less water and PVA film with 10 % CNF and 10 % TA absorbed about 80 % less water than the neat PVA film after the films were soaked in water for one hour. The better properties of the composite films produced are due to hydrogen and ester bonds between the components of the composite, which was confirmed by FT-IR spectroscopy. Antioxidant effective films were also obtained due to the biologically active TA to the PVA and PVA/CNF systems.

Multifunctional composite films based on polyvinyl alcohol, quaternary ammonium salt modified cellulose nanofibers and tannic acid-iron ion coordination complexes for food packaging

The development of sustainable and well-performing food packaging materials takes on critical significance, whereas it is still challenging. To overcome the shortcomings of polyvinyl alcohol (PVA) as a degradable packaging material, in this work, hydrophobic quaternary ammonium salt (QAS) modified cellulose nanofibers (CNF) and tannic acid‑iron ion coordination complexes (TA-Fe) were adopted for the preparation of functional PVA films. The modified CNF (CNF-QAS) not only improved the mechanical properties and water resistance of PVA, but also endowed it with antibacterial ability. In addition, the synergistic antibacterial capability with CNF-QAS was achieved using TA-Fe with photothermal therapy. As a result, the modulus, elongation at break, tensile strength, and water contact angle of the prepared PVA films were examined as 88 MPa, 200 %, 11.7 MPa, and 94.8°, respectively. Furthermore, with the assistance of CNF-QAS and TA-Fe, the films inhibited the growth of E. coli and S. aureus by 99.8 % and 99.7 %, respectively, and they exhibited high cell viability of 90.5 % for L929 fibroblasts. Based on the above encouraging properties, the functional PVA films could significantly extend the shelf life of oranges for over two weeks, proving the excellent application prospects in the food packaging field.

Synthesis of methylcellulose-polyvinyl alcohol composite, biopolymer film and thermostable enzymes from sugarcane bagasse

Agro-industrial wastes and by-products are the natural and abundant resources of biomaterials to obtain various value-added items such as biopolymer films, bio-composites and enzymes. This study presents a way to fractionate and to convert an agro-industrial residue, sugarcane bagasse (SB), into useful materials with potential applications. Initially cellulose was extracted from SB which was then converted into methylcellulose. The synthesized methylcellulose was characterized by scanning electron microscopy and FTIR. Biopolymer film was prepared by using methylcellulose, polyvinyl alcohol (PVA), glutaraldehyde, starch and glycerol. The biopolymer was characterized to exhibit 16.30 MPa tensile strength, 0.05 g/m² h of water vapor transmission rate, 366 % of water absorption to its original weight after 115 min of immersion, 59.08 % water solubility, 99.05 % moisture retention capability and 6.01 % of moisture absorption after 144 h. Furthermore, in vitro studies on absorption and dissolution of model drug by biopolymer showed 2.04 and 104.59 % of swelling ratio and equilibrium water content, respectively. Biocompatibility of the biopolymer was checked by using gelatin media and it was observed that swelling ratio was higher in initial 20 min of contact. The extracted hemicellulose and pectin from SB were fermented by a thermophilic bacterial strain, Neobacillus sedimentimangrovi UE25 that yielded 12.52 and 6.4 IU mL^-1 of xylanase and pectinase, respectively. These industrially important enzymes further augmented the utility of SB in this study. Therefore, this study emphasizes the possibility for industrial application of SB to form various products.

Processing, Properties, Modifications, and Environmental Impact of Nanocellulose/Biopolymer Composites: A Review

The increasing concerns about plastic pollution and climate change have encouraged research into bioderived and biodegradable materials. Much attention has been focused on nanocellulose due to its abundance, biodegradability, and excellent mechanical properties. Nanocellulose-based biocomposites are a viable option to fabricate functional and sustainable materials for important engineering applications. This review addresses the most recent advances in composites, with a particular focus on biopolymer matrices such as starch, chitosan, polylactic acid, and polyvinyl alcohol. Additionally, the effects of the processing methods, the influence of additives, and the outturn of nanocellulose surface modification on the biocomposite's properties are outlined in detail. Moreover, the change in the composites' morphological, mechanical, and other physiochemical properties due to reinforcement loading is reviewed. Further, mechanical strength, thermal resistance, and the oxygen-water vapor barrier properties are enhanced with the incorporation of nanocellulose into biopolymer matrices. Furthermore, the life cycle assessment of nanocellulose and composites were considered to analyze their environmental profile. The sustainability of this alternative material is compared through different preparation routes and options.

Trends and challenges in the development of bio-based barrier coating materials for paper/cardboard food packaging; a review

Currently, petroleum-based synthetic plastics are used as a key barrier material in the paper-based packaging of several food and nonfood goods. This widespread usage of plastic as a barrier lining is not only harmful to human and marine health, but it is also polluting the ecosystem. Researchers and food manufacturers are focused on biobased alternatives because of its numerous advantages, including biodegradability, biocompatibility, non-toxicity, and structural flexibility. When used alone or in composites/multilayers, these biobased alternatives provide strong barrier qualities against grease, oxygen, microbes, air, and water. According to the most recent literature reports, biobased polymers for barrier coatings are having difficulty breaking into the business. Technological breakthroughs in the field of bioplastic production and application are rapidly evolving, proffering new options for academics and industry to collaborate and develop sustainable packaging solutions. Existing techniques, such as multilayer coating of nanocomposites, can be improved further by designing them in a more systematic manner to attain the best barrier qualities. Modified nanocellulose, lignin nanoparticles, and bio-polyester are among the most promising future candidates for nanocomposite-based packaging films with high barrier qualities. In this review, the state-of-art and research advancements made in biobased polymeric alternatives such as paper and board barrier coating are summarized. Finally, the existing limitations and potential future development prospects for these biobased polymers as barrier materials are reviewed.

Extraction and Characterization of Cellulose from Jerusalem Artichoke Residue and Its Application in Blueberry Preservation

The utilization of industrial by-products is becoming more and more important for resource utilization. In this study, soluble dietary fiber (SDF) was extracted from Jerusalem artichoke residue, and a series of characterizations of SDF were carried out. The results showed that SDF had good properties. SDF (0%, 0.1%, 0.2%, 0.3%, and 0.4%) and chitosan (2%) were further used to prepare the coating that was used for the preservation of blueberry. The chemical structure of the film was obtained by FT-IR and XRD analysis. The microstructure of the film was analyzed by SEM, and the properties of the film were tested. The blueberry fresh-keeping test proved that the SDF-added film could effectively prolong the quality of blueberries in storage for 16 days. After 16 days of storage, compared with the control group, the decay rate of the coating group with 0.2% SDF decreased by 16.3%, the consumption of organic acids decreased by 43.7%, and the content of anthocyanin increased by 29.3%. SDF has a potential application in food preservation.

Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials

Polyvinyl alcohol (PVA) is one of the few biodegradable synthetic resins from petroleum-based sources that can alleviate white pollution in the environment. PVA film materials have excellent properties, such as high barrier, high transparency, high toughness, biocompatibility, and adjustable water solubility. However, due to the presence of hydrophilic hydroxyl groups in the side chain of PVA resin, when PVA film is placed in a humid or water environment, swelling or even dissolution will occur, which greatly limits its application. Therefore, it is necessary to modify PVA resin to improve water resistance without reducing other properties and can also impart various functionalities to it, thereby widening the application range. This paper reviews the water-resistant modification methods of polyvinyl alcohol and the application of water-resistant films and provides an outlook on the development trend of PVA water-resistant films.

Lignocellulose Nanofibre Obtained from Agricultural Wastes of Tomato, Pepper and Eggplants Improves the Performance of Films of Polyvinyl Alcohol (PVA) for Food Packaging

Films formulated with polyvinyl alcohol (PVA) (synthetic biopolymer) were reinforced with lignocellulose nanofibres (LCNF) from residues of vegetable production (natural biopolymer). The LCNF were obtained by mechanical and chemical pre-treatment by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and added to the polyvinyl alcohol (polymer matrix) with the aim of improving the properties of the film for use in food packaging. The mechanical properties, crystallinity, thermal resistance, chemical structure, antioxidant activity, water barrier properties and optical properties (transparency and UV barrier), were evaluated. In general, with the addition of LCNF, an improvement in the studied properties of the films was observed. In terms of mechanical properties, the films reinforced with 7% LCNF TEMPO showed the best results for tensile strength, Young’s modulus and elongation at break. At the same LCNF proportion, the thermal stability (T_max) increased between 5.5% and 10.8%, and the antioxidant activity increased between 90.9% and 191.8%, depending on the raw material and the pre-treatment used to obtain the different LCNF. Finally, a large increase in UV blocking was also observed with the addition of 7% LCNF. In particular, the films with 7% of eggplant LCNF showed higher performance for Young’s modulus, elongation at break, thermal stability and UV barrier. Overall, results demonstrated that the use of LCNF generated from agricultural residues represents a suitable bioeconomy approach able to enhance film properties for its application in the development of more sustainable and eco-friendly food packaging systems.