A review of cellulose and its derivatives in biopolymer-based for food packaging application

Effect of carbon dot-doped Ti-MOF on CMC/Agar film and active packaging application on storage quality of fruits

Ti-metal organic framework (Ti-MOF) doped with carbon dots (CDs) with enhanced antibacterial potential was synthesized using solvothermal-assisted mechanical stirring and used for the fabrication of CMC/Agar-based active packaging films. The incorporation of CD@Ti-MOF not only improved the tensile strength of the CMC/Agar film by 17.4% but also exhibited strong antioxidant activity with 100% of ABTS and 57.8% of DPPH radical scavenging using 0.64 cm2/mL of CMC/Agar/CD@Ti-MOF film. Furthermore, water vapor permeability, oxygen permeability, and ultraviolet light-blocking ability (95.7% of UV-B and 84.7% of UV-A) were improved significantly. The CMC/Agar/CD@Ti-MOF film showed strong antibacterial activity and could inhibit the progress of E. coli up to 8.2 Log CFU/mL and completely stopped the growth of L.monocytogenes after 12 h of incubation. Additionally, CMC/Agar/CD@Ti-MOF film extended the shelf life of cherry tomatoes preserved at 4 °C and delayed the quality degradation, maintaining the visual aspects of the packaging.

Advances in the preparation and application of cellulose-based antimicrobial materials: A review

The rise of polymer materials in modern life has drawn attention to renewable, easily biodegradable, environmentally-friendly bio-based polymers. Notably, significant research has been dedicated to creating green antimicrobial functional materials for the biomedical field using natural polymer materials. Cellulose is a rich natural biomass organic polymer material. Given its favorable attributes like film-forming capability, biodegradability, and biocompatibility, it is extensively employed to tackle a wide range of challenges confronting humanity today. However, its inherent drawbacks, such as insolubility in water and most organic solvents, hygroscopic nature, difficulty in melting, and limited antimicrobial properties, continue to pose challenges for realizing the high-value applications of cellulose. Achieving multifunctionality and more efficient application of cellulose still poses major challenges. In this regard, the current development status of cellulose materials was reviewed, covering the classification, preparation methods, and application status of cellulose-based antimicrobial materials. The application value of cellulose-based antimicrobial materials in biomedicine, textiles, food packaging, cosmetics and wastewater treatment was summarised. Finally, insights were provided into the developing prospects of cellulose-based antimicrobial materials were provided.

New insights into the pH-dependent removal of sulfamethoxazole in peracetic acid activation systems: From mechanistic exploration to practical application potentials

Peracetic acid (PAA) as emerging oxidant in advanced oxidation processes (AOPs) has attracted widespread attention in purifying water pollution. In this research, the removal of target contaminant (sulfamethoxazole, SMX) was investigated through PAA activation by a facile catalyst (Co@C), and the active sites of catalyst were identified as sp3-C, Oads, and Co0 by correlation analysis. Especially, different pH adjustment strategies were designed, including System A (adjusting pH after adding PAA) and System B (adjusting pH before adding PAA), to investigate the impact of oxidant acidity and alkalinity on solution microenvironment as well as effect and mechanism of pollutant removal. The results showed that HO· and CH3C(O)OO· dominated in System A, while Co(IV)O2+ was also observed in System B. Both systems showed optimal SMX degradation (98 %). However, System A exhibited excellent water quality tolerance (efficiency > 78 %), superior sustained catalyst activation (efficiency > 80 % in 40 h), less ion leaching (41 μg L-1), and lower products toxicity. Moreover, the pH of solution after reaction in System B was intensely acidic, requiring costly pH adjustments for discharge. This study unveils the strategy of adjusting pH after adding PAA is preferable for water purification, enriching the emerging research of PAA-based AOPs for the remediation of environments.

Facile fabrication of microfibrillated cellulose-based aerogels incorporated with nisin/β-cyclodextrin microcapsule for channel catfish preservation

In this study, a hydrophobic and antibacterial pad was prepared to preserve Channel Catfish (Ictalurus punctatus). The pad composite the microfibrillated cellulose and β-cyclodextrin/nisin microcapsules. The hydrophobic pad ensures a dry surface in contact with the fish, reducing microbial contamination. The pad has a low density and high porosity, making it lightweight and suitable for packaging applications, while also providing a large surface area for antibacterial activity. Results demonstrated that this antibacterial pad exhibits an ultralow density of 9.0 mg/cm3 and an ultrahigh porosity of 99.10%. It can extend the shelf life of Channel Catfish fillets to 9 days at 4 °C, with a total volatile base nitrogen below 20 mg/100 g. The study proposes a novel solution for preserving aquatic products by combining antibacterial substances with the natural base material aerogel. This approach also extends the utilization of aerogel and nisin in food packaging.

Development of multifunctional chitosan-based composite film loaded with tea polyphenol nanoparticles for strawberry preservation

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation.

Sustainable production of cellulosic biopolymers for enhanced smart food packaging: An up-to-date review

Biodegradable and sustainable food packaging (FP) materials have gained immense global importance to reduce plastic pollution and environmental impact. Therefore, this review focused on the recent advances in biopolymers based on cellulose derivatives for FP applications. Cellulose, an abundant and renewable biopolymer, and its various derivatives, namely cellulose acetate, cellulose sulphate, nanocellulose, carboxymethyl cellulose, and methylcellulose, are explored as promising substitutes for conventional plastic in FP. These reviews focused on the production, modification processes, and properties of cellulose derivatives and highlighted their potential for their application in FP. Finally, we reviewed the effects of incorporating cellulose derivatives into film in various aspects of packaging properties, including barrier, mechanical, thermal, preservation aspects, antimicrobial, and antioxidant properties. Overall, the findings suggest that cellulose derivatives have the potential to replace conventional plastics in food packaging applications. This can contribute to reducing plastic pollution and lessening the environmental impact of food packaging materials. The review likely provides insights into the current state of research and development in this field and underscores the significance of sustainable food packaging solutions.

Development of ternary polymeric film based on modified mango seed kernel starch, carboxymethyl cellulose, and gum acacia to extend the shelf-life of bun-bread

Non-conventional starch sources have attracted substantial attention due to their preferred physicochemical and mechanical properties similar to conventional sources. This study aimed to enhance the mechanical properties of mango seed kernel starch (MSKS) based films reinforced with carboxymethyl cellulose (CMC) and gum acacia (GA). Physical modification of MSKS was carried out using microwave-assisted at 180 W for 1 min. SEM results confirmed the oval and irregular shape of starch. The particle size of native starch (NS) (754.9 ± 20.4 nm) was higher compared to modified starch (MS) 336.6 ± 88.9 nm with a surface charge of -24.80 ± 3.92 to -34.87 ± 3.92 mV, respectively. Several functional groups including hydroxyl (OH) and carboxyl (CH) were confirmed in NS and MS. Different ratios of the MS, NS, CMC, and GA were used for the fabrication of films. Results revealed the higher tensile strength of M/C/G-1 (57.45 ± 0.05 nm) and M/C/G-2 (50.77 ± 0.58), compared to control C-4 (100 % native starch) (4.82 ± 0.04) respectively. The ternary complex provided excellent permeability against moisture and the film with a higher starch concentration confirmed the uniform thickness (0.09-0.10 mm). Furthermore, selected films (M/C/G-1 and M/C/G-2) reduced the microbial growth and weight loss of the bun compared to the control (C-4) film. Thus, the ternary complex maintained the freshness of the bun-bread for 14 days. It can be potentially used as a cost-effective and eco-friendly packaging material for food applications.

Synthesis strategies, regeneration, cost analysis, challenges and future prospects of bacterial cellulose-based aerogels for water treatment: A review

Clean water is an integral part of industries, agricultural activities and human life, but water contamination by toxic dyes, heavy metals, and oil spills is increasingly serious in the world. Aerogels with unique properties such as highly porous and extremely low density, tunable surface modification, excellent reusability, and thermal stability can contribute to addressing these issues. Thanks to high purity, biocompatibility and biodegradability, bacterial cellulose can be an ideal precursor source to produce aerogels. Here, we review the modification, regeneration, and applications of bacterial cellulose-based aerogels for water treatment. The modification of bacterial cellulose-based aerogels undergoes coating of hydrophobic agents, carbonization, and incorporation with other materials, e.g., ZIF-67, graphene oxide, nanoparticles, polyaniline. We emphasized features of modified aerogels on porosity, hydrophobicity, density, surface chemistry, and regeneration. Although major limits are relevant to the use of toxic coating agents, difficulty in bacterial culture, and production cost, the bacterial cellulose aerogels can obtain high performance for water treatment, particularly, catastrophic oil spills.

Cellulose-based materials in environmental protection: A scientometric and visual analysis review

As sustainable materials, cellulose-based materials have attracted significant attention in the field of environmental protection, resulting in the publication of numerous academic papers. However, there is a scarcity of literature that involving scientometric analysis within this specific domain. This review aims to address this gap and highlight recent research in this field by utilizing scientometric analysis and a historical review. As a result, 21 highly cited articles and 10 mostly productive journals were selected out. The scientometric analysis reveals that recent studies were objectively clustered into five interconnected main themes: extraction of cellulose from raw materials and its degradation, adsorption of pollutants using cellulose-based materials, cellulose-acetate-based membrane materials, nanocellulose-based materials, and other cellulose-based materials such as carboxymethyl cellulose and bacterial cellulose for environmental protection. Analyzing the distribution of author keywords and thoroughly examining relevant literature, the research focuses within these five themes were summarized. In the future, the development of eco-friendly and cost-effective methods for extracting and preparing cellulose and its derivatives, particularly nanocellulose-based materials, remains an enduring pursuit. Additionally, machine learning techniques holds promise for the advancement and application of cellulose-based materials. Furthermore, there is potential to expand the research and application scope of cellulose-based materials for environmental protection.

Preparation of Cellulose Fiber Loaded with CuO Nanoparticles for Enhanced Shelf Life and Quality of Tomato Fruit

The present study reports on the preparation of a cellulose fiber (CF) composite from D. lutescens, combined with copper oxide nanoparticles (DL@CF/CuO), to prolong the shelf life of tomatoes after harvest. The isolated cellulose fiber material was comprehensively characterized using XRD, FTIR, and FE-SEM analyses. The DLCF and DL@CF/CuO nanoparticles exhibited crystalline cellulose, as indicated by the XRD investigation. Both DLCF and DL@CF/CuO showed O-H and C-H FTIR spectra with identifiable vibrational peaks. The FE-SEM images depicted the dispersion of DL@CF/CuO-based fibers in a cellulose fiber matrix containing CuO nanoparticles. A 0.3% (wt/wt), a solution of DL@CF/CuO was coated onto the surface of early ripening tomato fruits. After a 25-day storage period at 25-29 °C and 85% RH, the results showed a significant extension in the shelf life of the tomato fruits, in line with changes in physiological properties and fruit quality. The extension of shelf life in tomato fruit epidermis treated with DL@CF/CuO was confirmed through FE-SEM analysis. L929 fibroblast cells were treated with the developed DL@CF/CuO nanocomposite, and no signs of toxicity were detected up to 75 µg/mL. Additionally, the DL@CF/CuO nanocomposite exhibited significant antifungal activity against Aspergillus flavus. In conclusion, this study provides novel insights for sustainable food security and waste control in the agricultural and food industries.

Development of cellulose/ZnO based bioplastics with enhanced gas barrier, UV-shielding effect and antibacterial activity

Development of renewable and biodegradable plastics with good properties, such as the gas barrier, UV-shielding, solvent resistance, and antibacterial activity, remains a challenge. Herein, cellulose/ZnO based bioplastics were fabricated by dissolving cellulose carbamate in an aqueous solution of NaOH/Zn(OH)42-, followed by coagulation in aqueous Na2SO4 solution, and subsequent hot-pressing. The carbamate groups detached from cellulose, and ZnO which transformed from cosolvent to nanofiller was uniformly immobilized in the cellulose matrix during the dissolution/regeneration process. The appropriate addition of ZnO (below 10.67 wt%) not only improved the mechanical properties but also enhanced the water and oxygen barrier properties of the material. Additionally, our cellulose/ZnO based bioplastic demonstrated excellent UV-blocking capabilities, increased water contact angle, and enhanced antibacterial activity against S. aureus and E. coli, deriving from the incorporation of ZnO nanoparticles. Furthermore, the material exhibited resistance to organic solvents such as acetone, THF, and toluene. Indeed, the herein developed cellulose/ZnO based bioplastic presents a promising candidate to replace petrochemical plastics in various applications, such as plastic toys, anti-UV guardrails, window shades, and oil storage containers, offering a combination of favorable mechanical, gas barrier, UV-blocking, antibacterial, and solvent-resistant properties.

Noni (Morinda citrifolia) leaf extract incorporated methylcellulose active films: A sustainable strategy for browning inhibition in apple slice packaging

Methylcellulose, a prominent polysaccharide prevalent in the food sector, was considered to fabricate the active films with glutaraldehyde as a crosslinker and Noni (Morinda citrifolia) Leaf Extract (NLE) as an active agent. FTIR analysis confirms the intermolecular -OH bonding, and SEM micrograms demonstrate methylcellulose active films' homogeneous, dense morphologic appearance. Due to the crosslinking effect of glutaraldehyde and noni leaf extract, tensile strength (41.83 ± 0.134 MPa) and crystallinity (62.91 %) of methylcellulose films were improved. Methylcellulose active films suppress water and moisture uptake at various relative humidities. The inhibition capability against foodborne pathogens and the excellent antioxidant activity [DPPH (93.191 ± 1.384 %) and ABTS (90.523 ± 1.412 %)] of NLE incorporation suggested that food packed in methylcellulose active films were effective against pathogenic and oxidative attacks. During preservation, to ensure the apple slices' nutritional values, they are covered with physiochemically enhanced methylcellulose active films for up to 120 h. The minimum reduction in vitamin C, reducing sugar content, percentage weight loss, pH, and total phenolic content of apple slices preserved in MGN active films at room temperature suggests it is an affordable and efficient replacement to traditional single-use plastic packaging in the cut fruit industry.

Green synthesis of Poria cocos polysaccharides-silver nanoparticles and their applications in food packaging

To reduce pollution caused by traditional plastic packaging and preparation of silver nanoparticles (AgNPs), this work aims to develop biological macromolecular packaging films with green synthesized AgNPs. In this study, a novel P. cocos polysaccharide (PCP) with a unique monosaccharide composition was extracted from Poria cocos (Schw.) Wolf. Then, this polysaccharide containing 24.68 % rhamnose was used as a stabilizer for the green synthesis of PCP-AgNPs for the first time. PCP-AgNPs exhibited excellent antibacterial activity against P. aeruginosa, E. coli, and S. aureus, with the highest antibacterial activity against E. coli (inhibition zone diameter = 11.14 ± 0.79 mm). Subsequently, PCP-AgNPs/chitosan (CS) film was successfully prepared by incorporating PCP-AgNPs into the CS film solution. Several experiments demonstrated that the addition of this nanomaterial promoted the formation of noncovalent interactions between CS and PCP-AgNPs, resulting in a more regular and denser film. Compared to the CS film and control group, the PCP-AgNPs/CS film significantly maintained the quality indexes of strawberries. Therefore, this composite film successfully extended the shelf life of strawberries. Regarding safety, these packaging films were not cytotoxic toward RAW264.7 cells. In conclusion, the environmentally friendly PCP-AgNPs/CS film has the potential to replace some traditional food packaging materials.

Nanocrystalline cellulose as a reinforcing agent for poly (vinyl alcohol)/ gellan-gum-based composite film for moxifloxacin ocular delivery

Nanocrystalline cellulose (NCC) is a star material in drug delivery applications due to its good biocompatibility, large specific surface area, high tensile strength (TS), and high hydrophilicity. Poly(Vinyl Alcohol)/Gellan-gum-based innovative composite film has been prepared using nanocrystalline cellulose (PVA/GG/NCC) as a strengthening agent for ocular delivery of moxifloxacin (MOX) via solvent casting method. Impedance analysis was studied using the capacitive sensing technique for examining new capacitance nature of the nanocomposite MOX film. Antimicrobial properties of films were evaluated using Pseudomonas aeruginosa and Staphylococcus aureus as gram-negative and gram-positive bacteria respectively by disc diffusion technique. XRD revealed the characteristic peak of NCC and the amorphous form of the drug. Sustained in vitro release and enhanced corneal permeation of drug were noticed in the presence of NCC. Polymer matrix enhanced the mechanical properties (tensile strength 22.05 to 28.41 MPa) and impedance behavior (resistance 59.23 to 213.23 Ω) in the film due to the presence of NCC rather than its absence (16.78 MPa and 39.03 Ω respectively). Occurrence of NCC brought about good antimicrobial behavior (both gram-positive and gram-negative) of the film. NCC incorporated poly(vinyl alcohol)/gellan-gum-based composite film exhibited increased mechanical properties and impedance behavior for improved ocular delivery of moxifloxacin.

Mechanically robust carboxymethyl cellulose/graphene oxide composite cross-linked by polyetherimide for fruits packaging and preservation system

Modulating the interactions between biopolymer matrix and nanofillers highly determined the mechanical performances of composite packaging materials. Herein, we innovatively proposed a sort of eco-friendly and mechanically robust carboxymethyl cellulose/graphene oxide/tannic acid/polyetherimide (CMC/GO/TA/PEI, CGTP) composite by employing PEI as cross-linker and TA as proton donor. The amidation reaction between -NH2 and -COOH chemically connected the CMC/GO, CMC/CMC and GO/GO and the physical interaction (e.g. hydrogen bonds and molecular entanglements) was beneficial to form dense structures. The chemical/physical bonds among polymers and nanofillers contributed to dissipate the external energy. The toughness was effectively reinforced from 1.68 MJ/m3 for CGTP0 to 4.63 MJ/m3 for CGTP1.0. Furthermore, the CGTP1.0 composite film also delivered improved gas (moisture and oxygen) barriers, UV protection and antimicrobial features. Originating from these merits, the shelf life of fresh fruits (e.g. strawberries, blueberries and cherry tomatoes) was prolonged at least 5 days under ambient conditions when the packaging box was covered by the fabricated CGTP1.0 film. Our findings not only provided a facial strategy to reinforce the interactions between biopolymer matrix and nanofillers, but also boosted the development of eco-friendly packaging materials with robust structures in the area of food packaging.

Recent progress on Pickering emulsion stabilized essential oil added biopolymer-based film for food packaging applications: A review

Nowadays food safety and protection are a growing concern for food producers and food industry. The stability of food-grade materials is key in food processing and shelf life. Pickering emulsions (PEs) have gained significant attention in food regimes owing to their stability enhancement of food specimens. PE can be developed by high and low-energy methods. The use of PE in the food sector is completely safe as it uses solid biodegradable particles to stabilize the oil in water and it also acts as an excellent carrier of essential oils (EOs). EOs are useful functional ingredients, the inclusion of EOs in the packaging film or coating formulation significantly helps in the improvement of the shelf life of the packed food item. The highly volatile nature, limited solubility and ease of oxidation in light of EOs restricts their direct use in packaging. In this context, the use of PEs of EOs is suitable to overcome most of the challenges, Therefore, recently there have been many papers published on PEs of EOs including active packaging film and coatings and the obtained results are promising. The current review amalgamates these studies to inform about the chemistry of PEs followed by types of stabilizers, factors affecting the stability and different high and low-energy manufacturing methods. Finally, the review summarizes the recent advancement in PEs-added packaging film and their application in the enhancement of shelf life of food.

Silane and fluorine free facile hydrophobicization of water hyacinth biomass for oil-water separations

As the adverse effects of using plastics and perfluorinated alkyl substances become more apparent, there is a growing need for sustainable hydrophobic products. Cellulose and its derivatives are the most abundant and widely used polymers, and cellulose-based products have great potential in industries where plastics and other hydrophobic polymers are used, such as stain-resistant fabrics, food packaging, and oil-water separation applications. In this study, we extracted cellulose from water hyacinth (WH) biomass, known for its negative environmental impact, and converted it into hydrophobic cellulose. This addresses the issue of managing WH waste and creating an environmentally friendly hydrophobic material. Initially, aldehyde groups were introduced through oxidation with periodate, followed by direct octadecyl amine (ODA) grafting onto dialdehyde cellulose (DAC) via a Schiff base condensation. The resulting ODA modified cellulose (ODA-C) was dispersed in ethanol and used to coat various materials, including cotton fabric, cellulose filter paper, and packaging paper. The modified materials showed excellent hydrophobicity as measured by their water contact angles (WCAs), and the application of the coating was demonstrated for oil-water separation, stain-resistant hydrophobic fabric, and paper-based packaging materials. FTIR, XRD, and WCA analysis confirmed the successful modification of cellulose. A high separation efficiency of 99% was achieved for diesel/water separation using modified filter paper (MoFP), under gravity. On application of the coating, cotton fabric became hydrophobic and resisted staining from dye, and paper-based packaging materials became more robust by becoming water-resistant. Overall, the facile synthesis, low cost, high efficiency, and use of environmentally friendly sustainable materials make this a promising strategy for hydrophobically modifying surfaces for a wide range of applications while reducing the menace of water hyacinth.

Novel insights on room temperature-induced cellulose dissolution mechanism via ZnCl2 aqueous solution: Migration, penetration, interaction, and dispersion

The unique molecular structure of cellulose makes it challenging to dissolve at room temperature (R.T.), and the dissolution mechanism remains unclear. In this study, we employed ZnCl2 aqueous solution for cellulose dissolution at R.T., proposing a novel four-stage dissolution mechanism. The efficient dissolution of cellulose in ZnCl2 aqueous solution at R.T. involves four indispensable stages: rapid migration of hydrated Zn2+ ions towards cellulose, sufficient penetration between cellulose sheets, strong interaction with cellulose hydroxyl groups, and effective dispersion of separated cellulose chains. The proposed four-stage dissolution mechanism was validated through theoretical calculations and experimental evidence. The hydrated Zn2+ ions in ZnCl2 + 3.5H2O solvent exhibited ideal migration, penetration, interaction, and dispersion abilities, resulting in efficient cellulose dissolution at R.T. Moreover, only slight degradation of cellulose occurred in ZnCl2 + 3.5H2O at R.T. Consequently, the regenerated cellulose materials obtained from ZnCl2 + 3.5H2O (R.T.) exhibited better mechanical properties. Notably, the solvent recovery rate reached about 95 % based on previous usage during five cycles. The solvent is outstanding for its green, low-cost, efficiency, simplicity, R.T. conditions and recyclability. This work contributes to a better understanding of the cellulose dissolution mechanisms within inorganic salt solvents at R.T., thereby guiding future development efforts towards greener and more efficient cellulosic solvents.

A Method for Sensing Dielectric Properties of Thin and Flexible Conductive Biocomposites

This study investigates the dielectric properties of conductive biocomposites (CBs), which are integral to the development of advanced materials for flexible electronics and medical devices. A novel method employing Microwave Reflectometry (MR) is introduced, utilizing a miniaturized Vector Network Analyzer (m-VNA) and a dedicated sensing element (SE), to extract the dielectric properties of CBs. The method is grounded in a minimization principle, aligning the measured S11 reflection scattering parameter with its electromagnetic (EM) simulation, facilitating a refined process for determining the dielectric properties. The experimental setup was meticulously engineered, optimized, and validated using reference dielectric samples (RDSs) with known dielectric properties. The method was then applied to three innovative CBs, resulting in an accurate extrapolation of their dielectric properties. The findings highlight the method's versatility, cost-efficiency, and applicability to ultra-thin and flexible biopolymer films, offering significant potential for advancements in flexible electronics and bio-sensing applications.

Electrophoretic Deposition of 58S Bioactive Glass- Polymer Composite Coatings on 316L Stainless Steel: An Optimization for Corrosion, Bioactivity, and Cytocompatibility

This study presents a facile fabrication of 58S bioactive glass (BG)-polymer composite coatings on a 316L stainless steel (SS) substrate using the electrophoretic deposition technique. The suspension characteristics and deposition kinetics of BG, along with three different polymers, namely ethylcellulose (EC), poly(acrylic acid) (PAA), and polyvinylpyrrolidone (PVP), have been utilized to fabricate the coatings. Among all coatings, 58S BG and EC polymers are selected as the final composite coating (EC6) owing to their homogeneity and good adhesion. EC6 coating exhibits a thickness of ∼18 μm and an average roughness of ∼2.5 μm. Herein, EC6 demonstrates better hydroxyapatite formation compared to PAA and PVP coatings in simulated body fluid-based mineralization studies for a period of 28 days. Corrosion studies of EC6 in phosphate-buffered saline further confirm the higher corrosion resistance properties after 14 days. In vitro cytocompatibility studies using human placental mesenchymal stem cells demonstrate an increase in cellular viability, attachment, and higher proliferation compared to the bare SS substrate. EC6 coatings promote osteogenic differentiation, which is confirmed via the upregulation of the OPN and OCN genes. Moreover, the EC6 sample exhibits improved antibacterial properties against Escherichia coli and Staphylococcus aureus compared to the uncoated ones. The findings of this work emphasize the potential of electrophoretically fabricated BG-EC composite coatings on SS substrates for orthopedic applications.

Highly flexible carbon nitride-polyethylene glycol-cellulose acetate film with photocatalytic antibacterial activity for fruit preservation

Cellulose acetate film, as a biodegradable and biomass-derived material, has great potential applications in food packaging. However, the poor mechanical and antibacterial properties limit its applications. Herein, a highly flexible carbon nitride-polyethylene glycol-cellulose acetate (CN-PEG-CA) film was successfully prepared by combining graphitic carbon nitride (g-C3N4) photocatalyst with cellulose acetate (CA). The g-C3N4 enables the film with antibacterial activity, as a green photocatalyst. PEG softens the rigid polymer CA and crosslinks CA, PEG, and g-C3N4 together by hydrogen bonding, as a flexible crosslinker. X-ray diffractometer (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectrum (FT-IR) characterizations confirmed the successful preparation of the CN-PEG-CA film. The mechanical property tests demonstrated that adding PEG increased the elongation at break of the film by about 4 times. The composite film had high antibacterial activity, and the bactericidal rates on Escherichia coli and Staphylococcus aureus were 99.98 % and 99.89 %, respectively. It effectively extended the shelf life of strawberries to 96 h and effectively maintained the quality of strawberries during storage. After 96 h, the weight loss rate of strawberries packaged with 15 % CN-PEG-CA film was 21.83 %, vitamin C content was 45.47 %, titratable acidity content was 0.89 %, and color, hardness and total soluble solids were well maintained. And biocompatibility test results showed that the film was safe and nontoxic. From the ecological and economic point of view, the highly flexible and biodegradable films with efficient photocatalytic antibacterial activity synthesized in this paper have great potential in the field of food packaging.

Copper supported modified magnetic carrageenan as a bio-based catalyst for the synthesis of novel scaffolds bearing the 1,2,3-triazole unit through the click reaction

The ongoing work delineates the design of a novel library of 1,2,3-triazole-attached phenylacetamides through molecular hybridization of propargyl and phenylacetamide derivatives. Copper-supported modified magnetic carrageenan serves as a green heterogeneous catalyst, ensuring high yield, efficient reaction times, high atom economy, utilization of an environmentally friendly catalyst from a natural source, and a straightforward workup procedure. The successful synthesis of the catalyst is confirmed and evaluated using various analytical techniques, while the synthetic compounds are characterized through 1H NMR and 13C NMR.

Transformative and sustainable insights of agricultural waste-based adsorbents for water defluoridation: Biosorption dynamics, economic viability, and spent adsorbent management

With the progression of civilization, the harmony within nature has been disrupted, giving rise to various ecocidal activities that are evident in every spheres of the earth. These activities have had a profound and far-reaching impact on global health. One significant example of this is the presence of fluoride in groundwater exceeding acceptable limits, resulting in the widespread occurrence of "Fluorosis" worldwide. It is imperative to mitigate the concentration of fluoride in drinking water to meet safety standards. While various defluoridation techniques exist, they often have drawbacks. Biosorption, being a simple, affordable and eco-friendly method, has gained preference for defluoridation. However, its limited commercialization underscores the pressing need for further research in this domain. This comprehensive review article offers a thorough examination of the defluoridation potential of agro-based adsorbents, encompassing their specific chemical compositions and preparation methods. The review presents an in-depth discussion of the factors influencing fluoride biosorption and conducts a detailed exploration of adsorption isotherm and adsorption kinetic models to gain a comprehensive understanding of the nature of the adsorption process. Furthermore, it evaluates the commercial viability through an assessment of regeneration potential and a cost analysis of these agro-adsorbents, with the aim of facilitating the scalability of the defluoridation process. The elucidation of the adsorption mechanism and recommendations for overcoming challenges in large-scale implementation offer a comprehensive outlook on this eco-friendly and sustainable approach to fluoride removal. In summary, this review article equips readers with a lucid understanding of agro-adsorbents, elucidates their ideal conditions for improved performance, offers a more profound insight into the fluoride biosorption mechanism, and introduces the concept of effective spent adsorbent management.

Cellulose, cellulose derivatives and cellulose composites in sustainable corrosion protection: challenges and opportunities

The use of cellulose-based compounds in coating and aqueous phase corrosion prevention is becoming more popular because they provide excellent protection and satisfy the requirements of green chemistry and sustainable development. Cellulose derivatives, primarily carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC), are widely employed in corrosion prevention. They function as efficient inhibitors by adhering to the metal's surface and creating a corrosion-inhibitive barrier by binding using their -OH groups. Their inhibition efficiency (%IE) depends upon various factors, including their concentration, temperature, chemical composition, the nature of the metal/electrolyte and availability of synergists (X-, Zn2+, surfactants and polymers). Cellulose derivatives also possess potential applications in anticorrosive coatings as they prevent corrosive species from penetrating and encourage adhesion and cohesion, guaranteeing the metal substrate underneath long-term protection. The current review article outlines the developments made in the past and present to prevent corrosion in both the coating phase and solution by using cellulose derivatives. Together with examining the difficulties of the present and the prospects for the future, the corrosion inhibition mechanism of cellulose derivatives in the solution and coating phases has also been investigated.

Enhanced dye sequestration with natural polysaccharides-based hydrogels: A review

Due to the expansion of industrial activities, the concentration of dyes in water has been increasing. The dire need to remove these pollutants from water has been heavily discussed. This study focuses on the reproducible and sustainable solution for wastewater treatment and dye annihilation challenges. Adsorption has been rated the most practical way of the several decolorization procedures due to its minimal initial investment, convenient utility, and high-performance caliber. Hydrogels, which are three-dimensional polymer networks, are notable because of their potential to regenerate, biodegrade, absorb bulky amounts of water, respond to stimuli, and have unique morphologies. Natural polysaccharide hydrogels are chosen over synthetic ones because they are robust, bioresorbable, non-toxic, and cheaply accessible. This study has covered six biopolymers, including chitosan, cellulose, pectin, sodium alginate, guar gum, and starch, consisting of their chemical architecture, origins, characteristics, and uses. The next part describes these polysaccharide-based hydrogels, including their manufacturing techniques, chemical alterations, and adsorption effectiveness. It is deeply evaluated how size and shape affect the adsorption rate, which has not been addressed in any prior research. To assist the readers in identifying areas for further research in this subject, limitations of these hydrogels and future views are provided in the conclusion.

A state-of-the-art review on plant-derived cellulose-based green hydrogels and their multifunctional role in advanced biomedical applications

The most prevalent carbohydrate on Earth is cellulose, a polysaccharide composed of glucose units that may be found in diverse sources, such as cell walls of wood and plants and some bacterial and algal species. The inherent availability of this versatile material provides a natural pathway for exploring and identifying novel uses. This study comprehensively analyzes cellulose and its derivatives, exploring their structural and biochemical features and assessing their wide-ranging applications in tissue fabrication, surgical dressings, and pharmaceutical delivery systems. The use of diverse cellulose particles as fundamental components gives rise to materials with distinct microstructures and characteristics, fulfilling the requirements of various biological applications. Although cellulose boasts substantial potential across various sectors, its exploration has predominantly unfolded within industrial realms, leaving the biomedical domain somewhat overlooked in its initial stages. This investigation, therefore, endeavors to shed light on the contemporary strides made in synthesizing cellulose and its derivatives. These innovative techniques give rise to distinctive attributes, presenting a treasure trove of advantages for their compelling integration into the intricate tapestry of biomedical applications.

Determination of the Mass Fractions of the Heavy Metals in the Recycled Cellulose Pulp

In the process of paper recycling, certain amounts of metals can be found in the cellulose suspension, the source of which is mainly printing inks. The paper industry often uses different technologies to reduce heavy metal emissions. The recycling of laminated packaging contributes to the formation of sticky particles, which affects the concentration of heavy metals. This study aimed to determine the mass fraction of metals in the different phases of the deinking process to optimize the cellulose pulp's quality and design healthy correct packaging products. In this research, the deinking flotation of laminated and non-laminated samples was carried out by the Ingede 11 method. As a result of the study, the mass fractions of metals in cellulose pulp were divided into four groups according to the mass fraction's increasing value and the metals' increasing electronegativity. The quantities of metals were analyzed using Inductively Coupled Mass Spectrometry (ICP-MS). The separation of metals from cellulose pulp is influenced by the presence of adhesives and the electronegativity of the metal. The results of the study show that the recycling process removes certain heavy metals very well, which indicates the good recycling potential of pharmaceutical cardboard samples.

Biodegradable Electrospun Membranes for Sustainable Industrial Applications

The escalating demand for sustainable industrial practices has driven the exploration of innovative materials, prominently exemplified by biodegradable electrospun membranes (BEMs). This review elucidates the pivotal role of these membranes across diverse industrial applications, addressing the imperative for sustainability. Furthermore, a comprehensive overview of biodegradable materials underscores their significance in electrospinning and their role in minimizing the environmental impact through biodegradability. The application of BEMs in various industrial sectors, including water treatment, food packaging, and biomedical applications, are extensively discussed. The environmental impact and sustainability analysis traverse the lifecycle of BEMs, evaluating their production to disposal and emphasizing reduced waste and resource conservation. This review demonstrates the research about BEMs toward an eco-conscious industrial landscape for a sustainable future.

Unlocking the potential of cotton stalk as a renewable source of cellulose: A review on advancements and emerging applications

Cotton stalk (CS) is a global agricultural residue, with an annual production of approximately 50 million tons, albeit with limited economic significance. The utilization of cellulose derived from CS has gained significant attention in green nanomaterial technologies. This interest stems from its unique properties, including biocompatibility, low density, minimal thermal expansion, eco-friendliness, renewability, and its potential as an alternative source for chemicals, petroleum, and biofuels. In this review, we delve into various extraction and characterization methods, the physicochemical attributes, recent advancements, and the applications of cellulose extracted from CS. Notably, the steam explosion method has proven to yield the highest cellulose content (82 %) from CS. Moreover, diverse physicochemical properties of cellulose can be obtained through different extraction techniques. Sulfuric acid hydrolysis, for instance, yields nanocrystalline cellulose fibers measuring 10-100 nm in width and 100-850 nm in length. Conversely, the steam explosion method yields cellulose fibers with dimensions of 10.7 μm in width and 1.2 mm in length. CS-derived products, including biochar, aerogel, dye adsorbents, and reinforcement fillers, find applications in various industries, such as environmental remediation and biodegradable packaging. This is primarily due to their ready availability, cost-effectiveness, and sustainable nature.

Preparation of hydroxypropyl methylcellulose/pueraria-based modified atmosphere film and its influence on delaying the senescent process of postharvest Agaricus bisporus

Based on the key factor of spontaneous modified atmosphere packaging (MAP)-gas permeability, a spontaneous MAP film was created for the preservation of Agaricus bisporus by delaying the senescence of white mushrooms. Compared with other mixed films, hydroxypropyl methylcellulose (HPMC)/pueraria (P)-2 showed better mechanical properties, barrier properties and thermal stability energy. Applying the HPMC/P-2 film for preserving white mushrooms can spontaneously adjust the internal gas environment. Moreover, the O2 concentration in the package remained stable at 1-2 %, and the CO2 concentration was between 8 % and 14 %. The film can effectively reduce the respiration rate of white mushrooms, inhibit enzymatic browning, maintain their good color and texture, and delay their aging. In conclusion, the HPMC/P-2 film can be used not only for fruit and vegetables preservation but also provide theoretical basis for sustainable food packaging.

Advanced hydrostable, recyclable and degradable cellulose hybrid films as renewable alternatives to synthetic plastics

Strong, tough and sustainable materials are in high demand in various engineering applications. We demonstrate a potential sustainable hybrid film made from natural cellulose and a biobased slurry. Through a simple and scalable approach, cellulose can be processed into an advanced material with over 2.8 and 9.2-fold increase in dry strength and toughness after curing and a 728-fold increase in wet strength, respectively. In addition, these hybrid composite films display an outstanding antioxidant activity surpassing 90 %, along with excellent ultraviolet radiation shielding and thermal insulation properties. Further, the hybrid films can be fabricated by integrating all-natural materials and still guarantee their unique functionality. We also demonstrate the feasibility of a circular bioeconomy by recycling the hybrid film using a green, deep eutectic solvent to fabricate a recycled hybrid film that displays excellent mechanical and optical properties. When recycling is unsuitable or economical, the hybrid film can naturally degrade in the soil under 6 months. These encouraging findings suggest the promise of cellulose hybrid films as a renewable, low-cost, tough, and strong material with the potential to replace nonrenewable synthetic plastics and products.

Fabrication of Schiff-base crosslinked films modified dialdehyde starch with excellent UV-blocking and antibacterial properties for fruit preservation

Starch-based films have received considerable attention, owing to their commendable biocompatible and biodegradable properties; however, their poor ultraviolet (UV)-blocking and antibacterial performances limit their application in fruit preservation. Herein, bio-based bifunctional benzoxazine (Bi-BOZ) compounds with different carbon chain lengths were synthesized, and the influence of chain lengths on the antibacterial effect was explored. Benzoxazine with 1,12-dodecanediamine as the amine source (BOZ-DDA) exhibited excellent antibacterial and antibiofilm activities, with minimum inhibitory concentrations of 21.7 ± 2.2 and 23.3 ± 2.6 μg/mL against Escherichia coli and Staphylococcus aureus, respectively, mainly because the electrostatic attraction and hydrophobic effect of BOZ-DDA, effectively disrupted the bacterial integrity. DS/DDA films with hydrophobic, antibacterial, and UV-resistant abilities were prepared by the Schiff-base reaction between BOZ-DDA and dialdehyde starch (DS). The interactions between the films increased with BOZ-DDA content, enhanced mechanical and barrier properties. DS/DDA films exhibited acid-responsive antibacterial activity attributed to the acid hydrolysis of Schiff bases, released of BOZ-DDA from the films, and the protonation of BOZ-DDA. DS/DDA films exhibited commendable antibacterial and anti-ultraviolet characteristics compared to commercially available films, allowing them to prevent the degradation of mangoes and grapes. As sustainable antibacterial materials, the multifunctional DS/DDA films manifest promising prospects in fruit preservation packaging applications.

Assessing the complementarity of time domain NMR, solid-state NMR and dynamic vapor sorption in the characterization of polysaccharide-water interactions

Characterizing the hygroscopic behavior of macromolecular assemblies is crucial for understanding biological processes as well as to develop tailor-made polysaccharides-based products. In this work, assemblies consisting of nanocelluloses (CNC or CNF) and/or glucomannan in different ratio were studied at different water activity levels, using a multi-analytical approach that combined Dynamic Vapor Sorption (DVS), Time-Domain Nuclear Magnetic Resonance (TD-NMR) and solid-state NMR (ss-NMR). The water retention capacity of the films, as a function of their composition, showed that an enrichment in konjac glucomannan in association with cellulose increased the water absorption capacity but decreased the water retention capacity. In addition, the combination of CNC and glucomannan appears to reduce the water absorption capacity of each polymer. Correlating the findings from the various methods allowed us to propose the use of TD-NMR data for predicting the water retention capacity. These results, summarized in a schematic representation, offer new insights into the organization of water molecules in polysaccharide assemblies in various humidity conditions.

Cellulose modification for sustainable polymers: overcoming problems of solubility and processing

Two new water-soluble cellulose derivatives were prepared by a two-step transformation with 1,3-propane sultone, followed by either maleic or succinic anhydride, thereby converting cellulose into a more easily processable form. It was found that the solubility was dependent on both the degree of substitution and the chemical properties of the substituents. The water-soluble cellulose has a molecular weight greater than 100 000 g mol-1 and both the morphology and molecular weight can be tuned by varying the reaction conditions. Furthermore, the flexible, two-step nature of the process allows for expansion of this methodology in order to prepare cellulose analogues for different applications.

Modulating digestibility and stability of Pickering emulsions based on cellulose nanofibers

Cellulose nanofibers (CNF) have been widely studied for their biodegradability and for their unique advantages as a stabilizer in Pickering-type emulsions. However, it is challenging to produce cellulose nanofibers from agroindustry waste with good techno-functional properties, without the use of harsh process conditions. Green alternatives (eco-friendly) have been studied to obtain nanofibers, such as enzymatic hydrolysis and/or application of mechanical processes. In this work, we used acid hydrolysis (as a control and example of an efficient method), enzymatic hydrolysis and a mechanical process (ultrasound) to obtain cellulose nanofibers. We also evaluated the effect of the presence of ethyl groups in the cellulosic matrix (ethylcellulose) on the stabilizing mechanism of emulsions. All cellulose nanofibers were able to produce Pickering emulsions at concentrations of 0.01-0.05% (w/w), although showing differences in emulsion stability and digestibility. Morphology of the different cellulose nanofibers affected the viscosity of the aqueous suspensions used as continuous phase. Emulsions with nanofibers obtained from cassava peel (without the presence of ethyl groups) were stabilized only by the Pickering-type mechanism, while ethylcellulose nanofibers also showed surface activity that contributed to the stability of the emulsion. Furthermore, these latter emulsions showed greater release of free fatty acids in in vitro digestion compared to emulsions stabilized by cellulose nanofibers. Despite these differences, in vitro digestion showed the potential of applying cellulose-stabilized emulsions to control the rate of lipid digestion, due to the low amount of free fatty acids released (<20%).

Carboxymethyl Scleroglucan Synthesized via O-Alkylation Reaction with Different Degrees of Substitution: Rheology and Thermal Stability

This paper presents the methodology for synthesizing and characterizing two carboxymethyl EOR-grade Scleroglucans (CMS-A and CMS-B). An O-Alkylation reaction was used to insert a hydrophilic group (monochloroacetic acid-MCAA) into the biopolymer's anhydroglucose subunits (AGUs). The effect of the degree of the carboxymethyl substitution on the rheology and thermal stability of the Scleroglucan (SG) was also evaluated. Simultaneous thermal analysis (STA/TGA-DSC), differential scanning calorimetry (DSC), X-ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (SEM/EDS) were employed to characterize both CMS products. FTIR analysis revealed characteristic peaks corresponding to the carboxymethyl functional groups, confirming the modification. Also, SEM analysis provided insights into the structural changes in the polysaccharide after the O-Alkylation reaction. TGA results showed that the carboxymethylation of SG lowered its dehydroxylation temperature but increased its thermal stability above 300 °C. The CMS products and SG exhibited a pseudoplastic behavior; however, lower shear viscosities and relaxation times were observed for the CMS products due to the breakage of the SG triple helix for the chemical modification. Despite the viscosity results, the modified Scleroglucans are promising candidates for developing new engineering materials for EOR processes.

Polysaccharide nanocomposites in wastewater treatment: A review

In modern times, wastewater treatment is vital due to increased water contamination arising from pollutants such as nutrients, pathogens, heavy metals, and pharmaceutical residues. Polysaccharides (PSAs) are natural, renewable, and non-toxic biopolymers used in wastewater treatment in the field of gas separation, liquid filtration, adsorption processes, pervaporation, and proton exchange membranes. Since addition of nanoparticles to PSAs improves their sustainability and strength, nanocomposite PSAs has gained significant attention for wastewater treatment in the past decade. This review presents a comprehensive analysis of PSA-based nanocomposites used for efficient wastewater treatment, focusing on adsorption, photocatalysis, and membrane-based methods. It also discusses potential future applications, challenges, and opportunities in adsorption, filtration, and photocatalysis. Recently, PSAs have shown promise as adsorbents in biological-based systems, effectively removing heavy metals that could hinder microbial activity. Cellulose-mediated adsorbents have successfully removed various pollutants from wastewater, including heavy metals, dyes, oil, organic solvents, pesticides, and pharmaceutical residues. Thus, PSA nanocomposites would support biological processes in wastewater treatment plants. A major concern is the discharge of antibiotic wastes from pharmaceutical industries, posing significant environmental and health risks. PSA-mediated bio-adsorbents, like clay polymeric nanocomposite hydrogel beads, efficiently remove antibiotics from wastewater, ensuring water quality and ecosystem balance. The successful use of PSA-mediated bio-adsorbents in wastewater treatment depends on ongoing research to optimize their application and evaluate their potential environmental impacts. Implementing these eco-friendly adsorbents on a large scale holds great promise in significantly reducing water pollution, safeguarding ecosystems, and protecting human health.

Effects of konjac glucan-nan/low-acyl gellan edible coatings loaded thymol-β-cyclodextrin microcapsules on postharvest blueberry

This study developed an edible antimicrobial coating using a blend of konjac glucomannan (KGM) and low acyl gellan gum (LAG) hydrogel to incorporate thymol nanoparticles (TKL). The optimized TKL formulation (TKL60) comprised 0.22% thymol microcapsules (TMs), 0.075% total polysaccharide content (KGM:LAG = 1:2), and 99.63% distilled water. When applied to blueberries, TKL60 significantly extended their shelf life to 42 d at 2 ± 0.5 °C, tripling that of control fruit. TKL60 reduced decay rate, weight loss, and respiration rate, delayed softening and senescence during cold storage. It preserved the outer epidermis by retaining cuticular waxes, curbing lipid oxidation, and sustaining defense-related enzyme activities. Flavor analysis revealed altered volatile compound concentrations in TKL60-treated berries, including decreased terpenes and benzaldehyde, and increased esters and aldehydes like 2-methylbutanol, 3-methylbutanol, and linalool. Discriminant Analysis highlighted TKL60's efficacy in delaying aroma deterioration by over 21 d. TKL60 exhibits potential as a substitute for synthetic coatings and chemical insecticides.

Exploring the diverse applications of Carbohydrate macromolecules in food, pharmaceutical, and environmental technologies

Carbohydrates are a class of macromolecules that has significant potential across several domains, including the organisation of genetic material, provision of structural support, and facilitation of defence mechanisms against invasion. Their molecular diversity enables a vast array of essential functions, such as energy storage, immunological signalling, and the modification of food texture and consistency. Due to their rheological characteristics, solubility, sweetness, hygroscopicity, ability to prevent crystallization, flavour encapsulation, and coating capabilities, carbohydrates are useful in food products. Carbohydrates hold potential for the future of therapeutic development due to their important role in sustained drug release, drug targeting, immune antigens, and adjuvants. Bio-based packaging provides an emerging phase of materials that offer biodegradability and biocompatibility, serving as a substitute for traditional non-biodegradable polymers used as coatings on paper. Blending polyhydroxyalkanoates (PHA) with carbohydrate biopolymers, such as starch, cellulose, polylactic acid, etc., reduces the undesirable qualities of PHA, such as crystallinity and brittleness, and enhances the PHA's properties in addition to minimizing manufacturing costs. Carbohydrate-based biopolymeric nanoparticles are a viable and cost-effective way to boost agricultural yields, which is crucial for the increasing global population. The use of biopolymeric nanoparticles derived from carbohydrates is a potential and economically viable approach to enhance the quality and quantity of agricultural harvests, which is of utmost importance given the developing global population. The carbohydrate biopolymers may play in plant protection against pathogenic fungi by inhibiting spore germination and mycelial growth, may act as effective elicitors inducing the plant immune system to cope with pathogens. Furthermore, they can be utilised as carriers in controlled-release formulations of agrochemicals or other active ingredients, offering an alternative approach to conventional fungicides. It is expected that this review provides an extensive summary of the application of carbohydrates in the realms of food, pharmaceuticals, and environment.

Advancing agriculture through bioresource technology: The role of cellulose-based biodegradable mulches

Agriculture plays a pivotal role in meeting the world's ever-growing food demands. However, traditional agricultural practices often have negative consequences for the environment, such as soil erosion and chemical runoff. Recently, there has been a pressing need for advance agricultural practices. Cellulose-based mulches offer a solution by optimizing agricultural productivity while minimizing harm. These mulches are made from renewable bioresources derived from cellulose-rich materials. Compared to plastic mulches, cellulose-based alternatives show potential in improving nutrient retention, soil health, weed suppression, water conservation, and erosion mitigation. The article investigates the characteristics and application methods of cellulose-based mulches, highlighting their biodegradability, water retention, crop protection, and weed suppression capabilities. It also evaluates their economic feasibility, emphasizing their potential to transform sustainable farming practices. Overall, cellulose-based mulches have the potential to revolutionize agriculture, addressing environmental concerns while optimizing productivity. They represent a significant step toward a more sustainable and resilient agricultural system.

Production of Cellulosic Microfibers from Coffee Pulp via Alkaline Treatment, Bleaching and Acid Hydrolysis

The present work deals with the production of cellulosic microfibers (CMFs) from coffee pulp. The experimental development corresponds to an experimental design of three variables (concentration, temperature and time) of alkaline treatment for delignification, finding that concentration, temperature and time were the most representative variables. Higher delignification was achieved by bleaching cellulosic fibers, followed by acid hydrolysis, thus producing cellulosic fibers with an average diameter of 5.2 µm, which was confirmed using scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). An X-ray diffraction (XRD) analysis revealed, via the crystallinity index, the presence of Type I cellulose and removal of lignocellulosic compounds through chemical treatments. The proximate chemical analysis (PChA) of coffee pulp helped to identify 17% of the crude fiber corresponding to the plant cell wall consisting of lignocellulosic compounds. The initial cellulose content of 26.06% increased gradually to 48.74% with the alkaline treatment, to 57.5% with bleaching, and to 64.7% with acid hydrolysis. These results attested to the rich cellulosic content in the coffee pulp.

Microplastic pollution in water environment of typical nature reserves and scenery districts in southern China

Microplastics were frequently detected in the ocean, freshwater environment and wastewater treatment plants. This study aims to fill up the knowledge gap of microplastic distribution in nature reserves and scenery districts. Microplastic samples were collected, the distribution characteristics were analyzed with a stereoscopic microscope and a Fourier transform infrared spectrometer, and the ecological risks of microplastic pollution were calculated. Microplastics were detected in all the collected water samples and the average abundances of microplastics in the surface water of eleven investigated nature reserves and scenery districts ranged from 542 to 5500 items/m3. The degrees of microplastic pollution of all the surveyed nature reserves and scenery districts were classified as hazard level I. Fiber microplastics represented the largest average proportion (67.4 %) and 91.7 % of the detected microplastics were smaller than 2 mm. Corresponding to the frequent detection of fiber microplastics, cotton was the most abundant (25.5 %) polymer type of the suspected microplastics, followed by polyamide (PA, 20.6 %), polyester (PET, 17.0 %), and cellulose (15.6 %). For the ecological risk of the microplastic polymers, six, two and three nature reserves and scenery districts were defined to be at hazard level I, II and III, respectively. In brief, microplastic pollution occurred in all the surveyed nature reserves/scenery districts and posed different degrees of ecological risks.

Antiviral functionalization of cellulose using tannic acid and tannin-rich extracts

Due to seasonally appearing viruses and several outbreaks and present pandemic, we are surrounded by viruses in our everyday life. In order to reduce viral transmission, functionalized surfaces that inactivate viruses are in large demand. Here the endeavor was to functionalize cellulose-based materials with tannic acid (TA) and tannin-rich extracts by using different binding polymers to prevent viral infectivity of both non-enveloped coxsackievirus B3 (CVB3) and enveloped human coronavirus OC43 (HCoV-OC43). Direct antiviral efficacy of TA and spruce bark extract in solution was measured: EC50 for CVB3 was 0.12 and 8.41 μg/ml and for HCoV-OC43, 78.16 and 95.49 μg/ml, respectively. TA also led to an excellent 5.8- to 7-log reduction of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infectivity. TA functionalized materials reduced infectivity already after 5-min treatment at room temperature. All the tested methods to bind TA showed efficacy on paperboard with 0.1 to 1% (w/v) TA concentrations against CVB3 whereas material hydrophobicity decreased activities. Specific signatures for TA and HCoV-OC43 were discovered by Raman spectroscopy and showed clear co-localization on the material. qPCR study suggested efficient binding of CVB3 to the TA functionalized cellulose whereas HCoV-OC43 was flushed out from the surfaces more readily. In conclusion, the produced TA-materials showed efficient and broadly acting antiviral efficacy. Additionally, the co-localization of TA and HCoV-OC43 and strong binding of CVB3 to the functionalized cellulose demonstrates an interaction with the surfaces. The produced antiviral surfaces thus show promise for future use to increase biosafety and biosecurity by reducing pathogen persistence.

The reduce of water vapor permeability of polysaccharide-based films in food packaging: A comprehensive review

Polysaccharide-based films are favored in the food packaging industry because of their advantages of green and safe characters, as well as natural degradability, but due to the structural defects of polysaccharides, they also have the disadvantages of high water vapor permeability (WVP), which greatly limits their application in the food packaging industry. To break the limitation, numerous methods, e.g., physical and/or chemical methods, have been employed. This review mainly elaborates the up-to-date research status of the application of polysaccharide-based films (PBFs) in food packaging area, including various films from cellulose and its derivatives, starch, chitosan, pectin, alginate, pullulan and so on, while the methods of reducing the WVP of PBFs, mainly divided into physical and chemical methods, are summarized, as well as the discussions about the existing problems and development trends of PBFs. In the end, suggestions about the future development of WVP of PBFs are presented.

Gas barrier coating based on cellulose nanocrystals and its preservation effects on mango

Mango is the "king of tropical fruits" because of its attractive appearance, delicious taste, rich aroma, and high nutritional value. However, mango keeps fast metabolizing after harvest, leading to water loss, starch conversion into sugar, texture softening, and decay. Here, a gas barrier coating based on cellulose nanocrystals (CNCs) is proposed to control the post-harvest metabolism of mango. The results of gas barrier permeability show that CNCs enhance the barrier ability of the chitosan (CS) membrane on mango by 202 % and 63 % for oxygen and water vapor, respectively. The gas-barrier coating reduces the climb in pH and the decrease in firmness by 84.9 % and 45.8 %, respectively, decelerating the conversion process from starch to sugar. Besides, introducing clove essential oil (CEO), the CEO mainly adsorbs and crystalizes on the hydrophobic facets of CNCs, presenting high compatibility, increases the antibacterial rate to nearly 100 %. As a consequence, the preservation period of the mango coated by the CNC-based membrane is at least 7-day longer than the control group. Such a gas-barrier coating based on eco-friendly composites must have excellent potential in the preservation of mango, and even for other tropical fruits.

Effect of Glycerol Concentrations on the Characteristics of Cellulose Films from Cattail (Typha angustifolia L.) Flowers

Plastic waste has become a big problem for the environment globally. Biodegradable polymers are a potential replacement for plastics that can have a positive outcome both environmentally and economically. In this work, we used acid hydrolysis and alkaline treatment to extract cellulose fibers from cattails. The obtained cellulose was used as a substrate for the fabrication of cellulose film using a casting technique on plastic plates. Different concentrations of the plasticizer, glycerol, were used to prepare films for comparison, and its effects on the film's characteristics were observed. The morphology, chemical structure, and thermal stability of the cattail cellulose (CTC) films were studied using techniques such as scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and thermogravimetric analysis (TGA), respectively. Measurements of transparency, moisture content (MC), water solubility (MS), and water contact angle (WCA) were also performed. Introducing glycerol into the films increased the transparency, MC, and WS values, as well as the gap width between film textures. However, it resulted in a decrease in the WCA of the films, showing that the hydrophilicity of the films is increased by the addition of glycerol. The interaction between the functional groups of cellulose and glycerol was established from the ATR-FTIR and XRD data. The obtained results indicated that glycerol affected the thermal stability and the degree of crystallinity of the produced films. Accordingly, the hydrophilicity of the cellulose film was increased by increasing the glycerol content; therefore, cattail cellulose films can be used as a biodegradable alternative to plastic in the future.

Fabrication and Testing of Crop Waste Ceiba pentandra Shell Powder Reinforced Biodegradable Composite Films

Ceiba pentandra shell powder (CPSP) biowaste is chosen as a biofiller combined with poly(vinyl alcohol) (PVA) as a matrix to make biofilms to increase the exploitation of biowaste materials and reduce the use of plastic materials. FTIR plots indicated no significant chemical reaction or formation of new functional groups during interaction between PVA and CPSP. XRD diffractograms showed that the crystallinity index (35.3, 38.6, 42.3, 46.4, and 48.5%) and crystalline size (18.14, 20.89, 23.23, 24.87, and 26.34 nm) of biofilms increased with CPSP loading (5-25 wt %). The PVA/CPSP films are thermally stable up to 322 °C. The peak highs of AFM images showed that the films' surface roughness gradually increased from 94.75 nm (5 wt % CPSP) to 320.17 nm (25 wt % CPSP). The FESEM micrographs clarify the homogeneous distribution of CPSP in the PVA matrix. Tensile strength and tensile modulus are noticeably increased by 26.32 and 37.92%, respectively, as a result of the loading of CPSP from 5 to 20 wt % in the PVA matrix. The PVA/CPSP films outperform pure PVA films in UV shielding (350-450 nm). The 59% weight loss of films was estimated during 60 days of burial. The fabricated biofilms maintained their suitable structural, thermal, morphological, and mechanical properties. Additionally, they exhibited consistent performance in ultraviolet (UV) barrier, opacity, water absorption, water vapor permeability, soil burial, and antimicrobial characteristics over time. Overall, PVA/CPSP (5-25 wt %) films are biodegradable and have promising applications as good packaging materials.

Recent Advances in Functional Cellulose-based Films with Antimicrobial and Antioxidant Properties for Food Packaging

The packaging of food plays a crucial role in food preservation worldwide. However, traditional packaging systems are passive layers with weak efficiency in protecting the food quality. Therefore, packaged foods are gradually spoiled due to the oxidation and growth of microorganisms. Additionally, most of the commercial packaging films are made of petroleum-based materials which raise environmental concerns. Accordingly, the development of eco-friendly natural-derived active packaging systems has increased the attention of scientists. Cellulose as the most abundant polysaccharide on earth with high biocompatibility, no toxicity, and high biodegradability has extensively been applied for the fabrication of packaging films. However, neat cellulose-based films lack antioxidant and antimicrobial activities. Therefore, neat cellulose-based films are passive films with weak food preservation performance. Active films have been developed by incorporating antioxidants and antimicrobial agents into the films. In this review, we have explored the latest research on the fabrication of antimicrobial/antioxidant cellulose-based active packaging films by incorporating natural extracts, natural polyphenols, nanoparticles, and microparticles into the cellulose-based film formulations. We categorized these types of packaging films into two main groups: (i) blend films which are obtained by mixing solutions of cellulose with other soluble antimicrobial/antioxidant agents such as natural extracts and polyphenols; and (ii) composite films which are fabricated by dispersing antimicrobial/antioxidant nano- or microfillers into the cellulose solution. The effect of these additives on the antioxidant and antimicrobial properties of the films has been explained. Additionally, the changes in the other properties of the films such as hydrophilicity, water evaporation rate, and mechanical properties have also been briefly addressed.

Native bacterial cellulose films based on kombucha pellicle as a potential active food packaging

The production of kombucha involves the synthesis of a bacterial cellulose-based native film by a microbial consortium, typically regarded as a waste by-product in commercial kombucha manufacturing. In this study, films were successfully obtained using the microbial consortium of kombucha, combined with infusions of black tea, green tea, rosehip, coffee, and licorice. These films exhibited a flexible rubbery-like structure and demonstrated inherent biological activity. Comparative analysis revealed that the licorice-based films exhibited a regular and less porous structure, while the green and black tea-based films displayed a porous structure, resulting in higher water permeability and swelling. Remarkably, green tea-based films showcased notable antioxidant activity (DPPH: %74.22 ± 2.05, ABTS: %81.59 ± 2.39) and exhibited antimicrobial properties against E. coli, S. aureus, and B. cereus, owing to their high phenolic content (1.62 ± 0.04 μg GAE/g). The antimicrobial efficacy of green tea-based films surpassed that of the other films against pathogenic microorganisms. By enhancing their hydrophobic properties, these innovative films hold promising potential as cost-effective, active, and environmentally friendly materials for food packaging applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05808-x.

Polysaccharide-based films: from packaging materials to functional food

A wider application of naturally derived polysaccharides is of great interest as materials for food packaging industry. Biocompatibility and biodegradability of polysaccharide-based films and coatings ally with a shift from application of non-biodegradable petrochemical polymers to the more environmentally friendly ones. Due to a range of inherent features in chemical structure and bioactivity, the polysaccharide materials could bring additional functionality to food packaging. The chelating ability of the polysaccharides provides also their application as carriers of additional active components, such as nanoparticles, essential oils and polyphenols. The improved physicochemical, antibacterial and antioxidant properties of the filled films allows to consider the edible polysaccharide-based films as functional food products. This review is aimed at analysis of evolution of polysaccharide-based food packaging materials from inert one starting from cellophane to recent research works on development of multicomponent polysaccharide-based functional food films and coatings.