Versatile nanocellulose-based nanohybrids: A promising-new class for active packaging applications

Application progress of nanocellulose in food packaging: A review

With the increasing environmental and ecological problems caused by petroleum-based packaging materials, the focus has gradually shifted to natural resources for the preparation of functional food packaging materials. In addition to biodegradable properties, nanocellulose (NC) mechanical properties, and rich surface chemistry are also fascinating and desired to be one of the most probable green packaging materials. In this review, we firstly introduce the recent progress of novel applications of NC in food packaging, including intelligent packaging, nano(bio)sensors, and nano-paper; secondly, we focus on the modification techniques of NC to summarize the properties (antimicrobial, mechanical, hydrophobic, antioxidant, and so on) that are required for food packaging, to expand the new synthetic methods and application areas. After presenting all the latest advances related to material design and sustainable applications, an overview summarizing the safety of NC is presented to promote a continuous and healthy movement of NC toward the field of truly sustainable packaging.

Advancements in Hybrid Cellulose-Based Films: Innovations and Applications in 2D Nano-Delivery Systems

This review paper delves into the realm of hybrid cellulose-based materials and their applications in 2D nano-delivery systems. Cellulose, recognized for its biocompatibility, versatility, and renewability, serves as the core matrix for these nanomaterials. The paper offers a comprehensive overview of the latest advancements in the creation, analysis, and application of these materials, emphasizing their significance in nanotechnology and biomedical domains. It further illuminates the integration of nanomaterials and advanced synthesis techniques that have significantly improved the mechanical, chemical, and biological properties of hybrid cellulose-based materials.

Highly efficient dissolution and reinforcement mechanism of robust and transparent cellulose films for smart packaging

The packaging of fresh foods increasingly focuses on renewable and eco-friendly cellulose films, but their low dissolution efficiency and weak mechanical strength greatly limit their wide application, which also cannot be used for smart packaging. Here, a highly efficient synergistic chloride-salt dissolution method was proposed to fabricate robust, transparent, and smart cellulose films. Cellulose films with appropriate Ca2+ concentration exhibited robust mechanical strength, better thermal stability, high transparency and crystallinity. The metal chelation of Ca2+ with cellulose chains could induce cellulose chain arrangement during the cellulose regeneration process. Particularly, compared to pure cellulose films, the tensile strength and elongation at break of cellulose films with suitable Ca2+ were increased by 167 % and 200 %, respectively. Moreover, optimal cellulose films can be used to reflect the quality of the fruit by detecting changes in ethanol gas. Hence, a novel strategy is presented to fabricate robust and transparent cellulose films with great potential application for smart packaging.

Recent advances in sustainable preparation of cellulose nanocrystals via solid acid hydrolysis: A mini-review

As a green and renewable nanomaterial, cellulose nanocrystals (CNC) have received numerous attention due to the unique structural features and superior physicochemical properties. Conventionally, CNC was isolated from lignocellulosic biomass mostly depending on sulfuric or hydrochloric acid hydrolysis. Although this approach is effective, some critical issues such as severe equipment corrosion, excessive cellulose degradation, serious environmental pollution, and large water usage are inevitable. Fortunately, solid acid hydrolysis is emerging as an economical and sustainable CNC production technique and has achieved considerable progress in recent years. Herein, the preparation of CNC by solid acid hydrolysis was summarized systematically, including organic solid acids (citric, maleic, oxalic, tartaric, p-toluenesulfonic acid) and inorganic solid acids (phosphotungstic, phosphoric, and Lewis acid). The advantages and disadvantages of organic and inorganic solid acid hydrolysis methods were evaluated comprehensively. Finally, the challenges and opportunities in the later exploitation and application of solid acid hydrolysis to prepare CNC in the industrial context are discussed. Considering the future development of this technology in the large-scale CNC production, much more efforts should be made in lowering CNC processing cost, fabricating high-solid-content and re-dispersible CNC, developing value-added applications of CNC, and techno-economic analysis and life cycle assessment on the whole process.

Ultraviolet blocking ability, antioxidant and antibacterial properties of newly prepared polyvinyl alcohol-nanocellulose‑silver nanoparticles-ChunJian peel extract composite film

In this work, nanocellulose (CNC) from waste water chestnut (WCT) shell was firstly used for preparing nanocomposite films, by using ChunJian peel extract (CJPE) as a green reducing agent to synthesize silver nanoparticles (AgNPs), and then loading them into polyvinyl alcohol-nanocellulose (PVA-CNC) matrix, a multifunctional nanocomposite material that could be used in food packaging was developed. The prepared films were tested for mechanical strength, barrier properties, thermal properties, antibacterial, antioxidant and biocompatibility through various characterizations. The PVA-CNC-AgNPs-CJPE film had good thermostability, mechanical strength, barrier properties, and biocompatibility. Compared with pure PVA film and PVA-CNC film, PVA-CNC-AgNPs-CJPE could shield over 95 % of the UVB (320-275 nm) spectrum and UVC (275-200 nm) spectrum and most of the UVA (400-320 nm). By disk diffusion analysis, the inhibition zones of PVA-CNC-AgNPs-CJPE film against E. coli, P. aeruginosa, S. aureus and E. faecalis were 22.3 mm, 25.0 mm, 22.0 mm and 19.3 mm, respectively. The milk antibacterial simulation test confirmed that PVA-CNC-AgNPs-CJPE film could effectively limit bacterial reproduction and prolong the shelf life of milk. PVA-CNC-AgNPs-CJPE film had excellent UV barrier properties, good antioxidant properties and high-efficiency antibacterial activity, which is expected to be widely used in sustainable nanocomposite food packaging.

Multi-functional nanocellulose based nanocomposites for biodegradable food packaging: Hybridization, fabrication, key properties and application

Nowadays, non-degradable plastic packaging materials have caused serious environmental pollution, posing a threat to human health and development. Renewable eco-friendly nanocellulose hybrid (NCs-hybrid) composites as an ideal alternative to petroleum-based plastic food packaging have been extensively reported in recent years. NCs-hybrids include metal, metal oxides, organic frameworks (MOFs), plants, and active compounds. However, no review systematically summarizes the preparation, processing, and multi-functional applications of NCs-hybrid composites. In this review, the design and hybridization of various NCs-hybrids, the processing of multi-scale nanocomposites, and their key properties in food packaging applications were systematically explored for the first time. Moreover, the synergistic effects of various NCs-hybrids on several properties of composites, including mechanical, thermal, UV shielding, waterproofing, barrier, antimicrobial, antioxidant, biodegradation and sensing were reviewed in detailed. Then, the problems and advances in research on renewable NCs-hybrid composites are suggested for biodegradable food packaging applications. Finally, a future packaging material is proposed by using NCs-hybrids as nanofillers and endowing them with various properties, which are denoted as "PACKAGE" and characterized by "Property, Application, Cellulose, Keen, Antipollution, Green, Easy."

Nanocellulose-based sensors in medical/clinical applications: The state-of-the-art review

In recent years, the considerable importance of healthcare and the indispensable appeal of curative issues, particularly the diagnosis of diseases, have propelled the invention of sensing platforms. With the development of nanotechnology, the integration of nanomaterials in such platforms has been much focused on, boosting their functionality in many fields. In this direction, there has been rapid growth in the utilisation of nanocellulose in sensors with medical applications. Indeed, this natural nanomaterial benefits from striking features, such as biocompatibility, cytocompatibility and low toxicity, as well as unprecedented physical and chemical properties. In this review, different classifications of nanocellulose-based sensors (biosensors, chemical and physical sensors), alongside some subcategories manufactured for health monitoring, stand out. Moreover, the types of nanocellulose and their roles in such sensors are discussed.

The use of essential oils in chitosan or cellulose-based materials for the production of active food packaging solutions: a review

In recent decades, interest in sustainable food packaging systems with additional functionality, able to increase the shelf life of products, has grown steadily. Following this trend, the present review analyzes the state of the art of this active renewable packaging. The focus is on antimicrobial systems containing nanocellulose and chitosan, as support for the incorporation of essential oils. These are the most sustainable and readily available options to produce completely natural active packaging materials. After a brief overview of the different active packaging technologies, the main features of nanocellulose, chitosan, and of the different essential oils used in the field of active packaging are introduced and described. The latest findings about the nanocellulose- and chitosan-based active packaging are then presented. The antimicrobial effectiveness of the different solutions is discussed, focusing on their effect on other material properties. The effect of the different inclusion strategies is also reviewed considering both in vivo and in vitro studies, in an attempt to understand more promising solutions and possible pathways for further development. In general, essential oils are very successful in exerting antimicrobial effects against the most diffused gram-positive and gram-negative bacteria, and affecting other material properties (tensile strength, water vapor transmission rate) positively. Due to the wide variety of biopolymer matrices and essential oils available, it is difficult to create general guidelines for the development of active packaging systems. However, more attention should be dedicated to sensory analysis, release kinetics, and synergetic action of different essential oils to optimize the active packaging on different food products. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

High mechanical property and antibacterial poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/functional enzymatically-synthesized cellulose biodegradable composite

Biodegradable materials with antibacterial properties are highly promising. A novel antimicrobial nanocellulose (ECP) was synthesized in one-step by enzyme-catalyzed method to improve the mechanical and antimicrobial properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)]. The biodegradable nanocomposites were prepared by melt blending and the performance analysis results show that the nanocomposites display enhanced mechanical performances and antibacterial activities. Compared with the neat P(HB-co-HV), the P(HB-co-HV) doped with 0.5 wt%-ECP shows the highest mechanical properties with yield strength/elongation at break of 29.3 MPa, 7.63 %, respectively, an increase of 38 %/59 %, and a clear inhibition zone against Staphylococcus aureus (S. aureus) of approximately 3.0 mm. As a heterogeneous nucleation agent, ECP optimizes nucleation, and the interfacial interaction between phenol group and matrix promotes the compatibility and dispersion of ECP, resulting in superior mechanical properties of ECP-based composites. The P(HB-co-HV)/ECP nanocomposites have great potential in biomedical materials especially for the bone defect filling material.

Swelling and Antimicrobial Activity Characterization of a GO-Reinforced Gelatin-Whey Hydrogel

Whey-based hydrogel samples with increasing concentrations of graphene oxide (GO) were studied, against a control sample (M), for swelling behavior in light of nuclear magnetic resonance (NMR) and mathematical models of the diffusion process and for antibacterial activity. Graphene oxide (GO) is an optimal filler for whey-based hydrogels, giving them improved mechanical and swelling properties at low concentrations. Crosslinking induces a certain stiffness of the hydrogels, which is why only the first part of the swelling process (<60%) follows the first-order model, while during the whole time interval, the swelling process follows the second-order diffusion model. The NMR relaxometry results are consistent with the swelling behavior of GO-reinforced whey−gelatin composite hydrogels, showing that higher GO concentrations induce a higher degree of cross-linking and, therefore, lower swelling capacity. Only hydrogel samples with higher GO concentrations demonstrated antibacterial activity.

Fabrication and Characterization of Eco-Friendly Polyelectrolyte Bilayer Films Based on Chitosan and Different Types of Edible Citrus Pectin

The eco-friendly polyelectrolyte bilayer films were prepared by layer-by-layer (LBL) casting method using chitosan (CS) and four types of edible citrus pectin as film substrates. The results showed that the polyelectrolyte bilayer films exhibited excellent comprehensive properties. Furthermore, the interaction between CS and pectin was closely related to the degree of methyl-esterification (DM), molecular weight (Mw), and zeta potential of pectin. The low DM, Mw, and high zeta potential of the low methyl-esterified pectin (LM) resulted in a denser internal structure of the bilayer film, stronger UV shielding performance, and stronger gas barrier ability. The high DM and Mw of the high methyl-esterified pectin (HM) endow the bilayer film with stronger mechanical properties, thermal stability, and antifogging property. The microstructural and spectroscopic analysis showed that there are hydrogen bonds and electrostatic interactions between the layers. Overall, the developed CS-pectin polyelectrolyte bilayer films provided potential applications for food bioactive packaging.

Recent advances on nanocellulose biomaterials for environmental health photoremediation: An overview

As one of the potential bionanomaterials, nanocellulose has appeared as a favorable candidate for photoremediation of the environment because of its abundance in nature, inexpensive, eco-friendly, decomposable, high surface area, and outstanding mechanical properties. The current review carefully summarized the diverse type of nanocellulose, their preparation approaches, and several previous works on the use of nanocellulose for photoremediation. These include the role of nanocellulose for the increased surface active site of the hybrid photocatalysts by providing a large surface area for enhanced adsorption of photons and pollutant molecules, as a dispersing agent to increase distribution of metal/non-metal dopants photocatalysts, as well as for controlled size and morphology of the dopants photocatalysts. Furthermore, the recommendations for upcoming research provided in this review are anticipated to ignite an idea for the development of other nanocellulose-based photocatalysts. Other than delivering beneficial information on the present growth of the nanocellulose biomaterials photocatalysts, this review is expected will attract more interest to the utilization of nanocellulose photocatalyst and distribute additional knowledge in this exciting area of environmental photoremediation. This could be attained by considering that a review on nanocellulose biomaterials for environmental health photoremediation has not been described elsewhere, notwithstanding intensive research works have been dedicated to this topic.

Bio-packaging based on cellulose acetate from banana pseudostem and containing Butia catarinensis extracts

Banana (Musa acuminata) pseudostem cellulose was extracted and acetylated (CA) to prepare membranes with potential use as bio-packages. The CA membrane was embedded by Butia seed (CA-BS) or Butia pulp (CA-BP) extracts obtained from Butia catarinenses (Butia). The produced CA, CA-BS, and CA-BP membranes were evaluated for their physical-chemical, mechanical, thermal, and antibacterial properties. The process for obtaining the cellulose yielded a material with about 92.17% cellulose (DS = 2.85). The purity, cellulose degree acetylation, and the incorporation of Butia extracts into the membranes were confirmed by FTIR. The CA-BS and CA-BP membranes showed a smaller contact angle and higher swelling ratio than the CA membrane. Furthermore, Butia seed or pulp extracts reduced the elastic modulus and deformation at break compared to the CA membrane. The DSC analysis suggested the compatibility between sections and the CA matrix, whereas the TGA analysis confirmed the thermal stability of the membranes. Moreover, less than 1% of the Butia seed and pulp extracts were put into a food simulant media from the membrane. Finally, the CA-BS and CA-BP membranes could inhibit the growth of Staphylococcus aureus and Escherichia coli on their surface, confirming the potential use of these membranes as bio-packaging for food preservation.