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

Antibacterial food packaging using biocompatible nickel oxide-infused cellulose acetate electrospun nanofibers

The present study included the environmentally friendly production of stable nickel nanoparticles (NiO NPs) using lemon and tomato, followed by their analysis and evaluation for their antibacterial properties against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Bacillus cereus. The Nickel oxide nanoparticles produced exhibited their maximum absorption at 276 nm in the UV-vis spectrum. The image captured FESEM revealed smooth nanofibers with an average diameter of around 259 ± 3.7 nm. X-ray diffraction (XRD) experiments verified the existence of elemental nickel and accurately determined the crystalline structure of nickel oxide nanoparticles. Novel green organic-inorganic hybrid nanofibers (NiO@CA) were synthesized using the electrospinning technique. These nanofibers are composed of NiO nanoparticles integrated into cellulose acetate nanofibers, which are particularly engineered for the purpose of fruit preservation. Robust antibacterial activity was shown by NiO nanoparticles and NiO@CA nanofiber against the assessed food pathogenic bacterial strains. NiO@CA nanofiber used as a surface coating on lemon and tomato prolonged their shelf life by preventing the degradation caused by food risks. The provided results indicate that NiO@CA nanofiber has the capacity to function as antimicrobial packaging for the purpose of food preservation. Enhancing food safety, prolonging shelf life, and offering an eco-friendly alternative to traditional materials, antibacterial food packaging made of biocompatible nickel oxide-infused cellulose acetate electrospun nanofibers is a great solution.

Cellulose and lignin nanoparticles from an Ayurvedic waste stream for essential oil-based active packaging to extend shelf life of strawberries

Cellulose and lignin nanoparticles (NCP and LNP) were successfully extracted from Dashamoola spent material (DSM), a residue from an Ayurvedic decoction. NCP had a particle size of 493.6 nm and a zeta potential of -30.9 mV, indicating good colloidal stability. FTIR confirmed the removal of non-cellulosic components, while TGA demonstrated thermal stability, with major degradation between 260 °C and 350 °C. A semi-crystalline structure of nanocellulose was indicated via XRD analysis. Oil-in-water emulsions of tea tree oil (TTO) were prepared using NCP (C at 4 %), LNP (L at 4 %), and a combination blend (2 % each of C and L in CL_TTO), with 16 % TTO, all in w/v. Among these, CL_TTO emulsions had the smallest particle size and highest stability. PVOH-based films, prepared with a 4 % w/v mixture of CL_TTO emulsion, PVOH, and glycerol, demonstrated improved tensile strength, Young's modulus, water vapour barrier properties, and water repellence. These films blocked 95 % UV transmittance, providing appreciable protection to light-sensitive products. PVOH-CL_TTO films also exhibited strong antioxidant activity (85 % DPPH scavenging) and antimicrobial property against E. coli. These films extended the shelf life of strawberries by preserving lightness, firmness, and pH for 14 days under chilling (4 °C). These findings highlight the potential of NCP and LNP obtained from DSM for producing sustainable active packaging which would valorizing Ayurvedic waste stream.

Cellulose-based delivery systems for bioactive ingredients: A review

Considering the outstanding advantages including abundant resources, structure-performance designability, impressive mechanical strength, and 3D network structure-forming ability, cellulose is an ideal material for encapsulating bioactive ingredients. Due to its low solubility in water, large-scaled morphology and poor flexibility, cellulose is unsuitable for the construction of carriers. Consequently, the majority of cellulose is employed following physical or chemical modification. Cellulose and its derivatives are extensively employed in the food industry, including fat replacement, food packaging composites, food additives, 3D-printed food and delivery systems. Their benefits in food delivery systems are particularly pronounced. Therefore, the distinguishing features, preparation methods, recent developments and effectiveness of different cellulose-based delivery systems for bioactive ingredients are discussed. Cellulose-based delivery systems offer unique advantages in terms of environmental impact reduction, modification facilitation, stimuli-responsive release as well as tailored design, and their application has gained widespread recognition. However, they are facing challenges in the application process comprising modification methods for cellulose-based materials, new methods for commercial preparation on a wide scale, cellulose-based multifunctional conveyance systems and systematic evaluation using in vivo experiments. In conclusion, this review provides theoretical references for the development of novel delivery carriers as well as the efficient application and popularization of cellulose-based delivery systems.

Recent Advances in Polysaccharide-Based Nanocomposite Films for Fruit Preservation: Construction, Applications, and Challenges

With the constantly escalating demand for safe food packaging, the utilization of biodegradable polysaccharide-based nanocomposite films is being explored as an alternative to traditional petrochemical polymer films (polyvinyl alcohol, polybutylene succinate, etc.). Polysaccharide-based films have excellent mechanical properties, water vapor transmission rates, and other physical characteristics. Films can fulfill numerous demands for fruit packaging in daily life. Additionally, they can be loaded with various types of non-toxic and non-biocidal materials such as bioactive substances and metal nanomaterials. These materials enhance bacterial inhibition and reduce oxidation in fruits while maintaining fundamental packaging functionality. The article discusses the design and preparation strategies of polysaccharide-based nanocomposite films and their application in fruit preservation. The types of films, the addition of materials, and their mechanisms of action are further discussed. In addition, this research is crucial for fruit preservation efforts and for the preparation of polysaccharide-based films in both scientific research and industrial applications.

Injectable, Biodegradable and Photothermal Hydrogel with Quorum Sensing Inhibitory Effects for Subcutaneous Fungal Infection Treatment

Owing to the high invasion depth and easy formation of biofilms, the treatment of subcutaneous fungal infection is intractable and challenging. Herein, we report an injectable and biodegradable hydrogel with bactericidal, quorum sensing inhibition and antioxidant activities for the in situ treatment of subcutaneous fungal infection. The hydrogel (BEPE) was constructed by irradiating mixed bovine serum albumin (BSA), ε-polylysine and epigallocatechin gallate (EGCG)-loaded mesoporous polydopamine (PDA) under near-infrared (NIR) light. BEPE exerted microbicidal effects against Candida albicans (99.5%) and Streptococcus mutans (99.6%) through synergistic photothermal effects and the microbiocidal activity of slowly released ε-polylysine. Moreover, the gently released EGCG from BEPE with relatively high bioavailability, synergistically inhibited and destroyed biofilms by inhibiting quorum sensing between microbes, resulting in an antibiofilm efficiency of 80.5% against C. albicans. An in vivo subcutaneous fungal infection study revealed that BEPE accelerates tissue regeneration via targeted formation, elimination of fungal infection and alleviation of inflammation in situ, thereby promoting wound healing. This biodegradable hydrogel strategy will facilitate the design of multifunctional microbicidal agents for targeted subcutaneous fungal infection treatment.

Active biodegradable bacterial cellulose films with potential to minimize the plastic pollution: Preparation, antibacterial application, and mechanism

Petroleum-based films have triggered a serious global pollution crisis because they are difficult to recycle, degrade, and reuse. Developing alternative sustainable active films represents a powerful strategy to address these issues. Here, a multifunctional biodegradable bacterial cellulose (BC) film incorporated with guanidine-based polymer (PHGH)/gallic acid (GA) was constructed (termed OBC-PHGH/GA). The resulting OBC-PHGH/GA film exhibited a highly interweaved nanofiber network structure with excellent tensile strength and ductility. The OBC-PHGH/GA film showed an excellent antibacterial effect against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with inhibition efficiencies of ∼99.99 % compared with the OBC film. Moreover, the as-prepared film showed excellent UV-shielding, antioxidant, and antifungal activities, showing great potential in food packaging. More importantly, the OBC-PHGH/GA film can be degraded into safe and reusable sugars, demonstrating outstanding environmental friendliness and sustainability. This work provides a promising and unique strategy for designing and fabricating green active packaging materials.

Iron doping enhances the bind stability of transpiration water to Zr-based MOFs packaging

The metabolic processes of fruits induce water vapor condensation in packaging, creating a high-humidity microenvironment that exacerbates the proliferation of microorganisms and causes food spoilage. Therefore, a Fe/Zr bimetallic organic framework (Fe-MOF-801) packaging (i.e., FeMGCF) with high binding stability to transpiration water was prepared based on transition metal Fe doping strategy, and the mechanism of its enhanced binding stability towards transpiration water was investigated. The results indicate that Fe enhances the interaction between MOFs and H2O by promoting the charge depletion at the O sites coordinated with Zr, thereby increasing the aggregation tendency of H2O in the T1 and T2 cavities (characterized by strong hydrogen bonding) of Fe-MOF-801, which increased the binding energy of MOFs to H2O by 29.6 %. Accordingly, the application of FeMGCF packaging extended the shelf life of tomatoes by 6 days and delayed the degradation of lycopene and anthocyanins during postharvest tomato preservation.

Polysaccharide-Based Packaging Coatings and Films with Phenolic Compounds in Preservation of Fruits and Vegetables-A Review

Considerable interest has emerged in developing biodegradable food packaging materials derived from polysaccharides. Phenolic compounds serve as natural bioactive substances with a range of functional properties. Various phenolic compounds have been incorporated into polysaccharide-based films and coatings for food packaging, thereby enhancing product shelf life by mitigating quality degradation due to oxidation and microbial growth. This review offers a comprehensive overview of the current state of polysaccharide-based active films and coatings enriched with phenolic compounds for preserving fruits and vegetables. The different approaches for the addition of phenols to polysaccharides-based packaging materials are discussed. The modifications in film properties resulting from incorporating polyphenols are systematically characterized. Then, the application of these composite materials as protectants and intelligent packaging in fruit and vegetables preservation is highlighted. In future, several points, such as the preservative mechanism, safety evaluation, and combination with other techniques along the whole supply chain could be considered to design polyphenol-polysaccharides packaging more in line with actual production needs.

Advances in the enhancement of mechanical and hydrophobic properties of nanocellulose-based packaging materials: A review

As environmental issues are hotly debated worldwide, finding suitable materials to replace petroleum-based materials as the next-generation packaging materials has become a research hotspot. Nanocellulose, as a biomass material widely available in nature, is favored for application in green packaging materials due to its environmentally friendly and bio-friendly characteristics. However, the unstable mechanical properties and strong hydrophilicity of nanocellulose limit its practical application in packaging materials. This paper starts with a discussion of nanocellulose-based packaging materials and focuses on methods to improve their mechanical and hydrophobic properties. The discussion on mechanical properties focuses on the contribution of carbon nanomaterials, which is then combined with hydrophobic modifications (including plant polyphenol modification, esterification, acetylation, in situ polymerization, etc.) to illustrate the impact on the performance of packaging materials in use. The relationship between the hydrophobic characteristics of packaging materials derived from nanocellulose and their comprehensive mechanical properties is meticulously elucidated. Furthermore, a theoretical framework is proposed, positing that enhancing the hydrophobicity of these materials can indirectly augment their mechanical attributes. This insight offers pivotal guidance for the advancement of next-generation, high-performance packaging materials based on nanocellulose.

Algal carbohydrates: Sources, biosynthetic pathway, production, and applications

Algae play a significant role in the global carbon cycle by utilizing photosynthesis to efficiently convert solar energy and atmospheric carbon dioxide into various chemical compounds, notably carbohydrates, pigments, lipids, and released oxygen, making them a unique sustainable cellular factory. Algae mostly consist of carbohydrates, which include a broad variety of structures that contribute to their distinct physical and chemical properties such as degree of polymerization, side chain, branching, degree of sulfation, hydrogen bond etc., these features play a crucial role in regulating many biological activity, nutritional and pharmaceutical properties. Algal carbohydrates have not received enough attention in spite of their distinctive structural traits linked to certain biological and physicochemical properties. Nevertheless, it is anticipated that there will be a significant increase in the near future due to increasing demand, sustainable source, biofuel generation and their bioactivity. This is facilitated by the abundance of easily accessible information on the structural data and distinctive characteristics of these biopolymers. This review delves into the different types of saccharides such as agar, alginate, fucoidan, carrageenan, ulvan, EPS and glucans synthesized by various macroalgal and microalgal systems, which include intracellular, extracellular and cell wall saccharides. Their structure, biosynthetic pathway, sources, production strategies and their applications in various field such as nutraceuticals, pharmaceuticals, biomedicine, food and feed, cosmetics, and bioenergy are also elaborately discussed. Algal polysaccharide has huge a scope for exploitation in future due to their application in food and pharmaceutical industry and it can become a huge source of capital and income.

Versatile synthesis of cellulose film with excellent electrothermal/photothermal dual responsiveness by introducing MXene and small molecule self-assembled nanosphere

Plant-derived biomaterials have great application prospects in solving environmental pollution and sustainable resource utilization, but the insufficient mechanical strength and lack of functional responsiveness often limit their further development. Inspired by natural small molecules functionalization, a vacuum-assisted filtration nanofibrillated cellulose (NFC)-based film with excellent antibacterial properties, mechanical strength, and electrothermal/photothermal dual-responsiveness was fabricated. As a natural bioactive molecule, antibacterial cinnamaldehyde (CA) is grafted onto tannic acid (TA) rich in pyrogallols via a small molecule self-assembly strategy, and then co-assembled with zinc acetate (ZA) through ion crosslinking to synthesize the functional TACA@ZA nanospheres. After incorporating the MXene and TACA@ZA, an inorganic-organic 3D network system was established in the NFC matrix through dynamic intermolecular hydrogen bonding and strong ionic cross-linking. The mechanical strength and toughness of hybrid composites are remarkably improved by 83.6 % and 418.9 %, respectively. Due to the synergistic effects of MXene and TACA@ZA, the designed NFC-based film also shows significantly enhanced antibacterial activity, UV-blocking ability, as well as photothermal and electrothermal performance. This bioinspired small molecule functionalization strategy opens an innovative design concept for the fabrication of multirole NFC-based biomaterials, which has great application prospects in the commercial fields of multifunctional adhesives, electronic devices, UV shielding coatings, and antibacterial materials.

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

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

Hemicellulose-Based Sensors: When Sustainability Meets Complexity

Hemicelluloses (HCs) are promising sustainable biopolymers with a great natural abundance, excellent biocompatibility, and biodegradability. Yet, their potential sensing applications remain limited due to intrinsic challenges in their heterogeneous chemical composition, structure, and physicochemical properties. Herein, recent advances in the development of HC-based sensors for different chemical analytes and physical stimuli using different transduction mechanisms are reviewed and discussed. HCs can be utilized as carbonaceous precursors, reducing, capping, and stabilizing agents, binders, and active components for sensing applications. In addition, different strategies to develop and improve the sensing capacity of HC-based sensors are also highlighted.

Recent advances review in tea waste: High-value applications, processing technology, and value-added products

Tea waste (TW) includes pruned tea tree branches, discarded summer and fall teas, buds and wastes from the tea making process, as well as residues remaining after tea preparation. Effective utilization and proper management of TW is essential to increase the economic value of the tea industry. Through effective utilization of tea waste, products such as activated carbon, biochar, composite membranes, and metal nanoparticle composites can be produced and successfully applied in the fields of fuel production, composting, preservation, and heavy metal adsorption. Comprehensive utilization of tea waste is an effective and sustainable strategy to improve the economic efficiency of the tea industry and can be applied in various fields such as energy production, energy storage and pharmaceuticals. This study reviews recent advances in the strategic utilization of TW, including its processing, conversion technologies and high value products obtained, provides insights into the potential applications of tea waste in the plant, animal and environmental sectors, summarizes the effective applications of tea waste for energy and environmental sustainability, and discusses the effectiveness, variability, advantages and disadvantages of different processing and thermochemical conversion technologies. In addition, the advantages and disadvantages of producing new products from tea wastes and their derivatives are analyzed, and recommendations for future development of high-value products to improve the efficiency and economic value of tea by-products are presented.

Biopolymers as Sustainable and Active Packaging Materials: Fundamentals and Mechanisms of Antifungal Activities

Developing bio-based and biodegradable materials has become important to meet current market demands, government regulations, and environmental concerns. The packaging industry, particularly for food and beverages, is known to be the world's largest consumer of plastics. Therefore, the demand for sustainable alternatives in this area is needed to meet the industry's requirements. This review presents the most commonly used bio-based and biodegradable packaging materials, bio-polyesters, and polysaccharide-based polymers. At the same time, a major problem in food packaging is presented: fungal growth and, consequently, food spoilage. Different types of antifungal compounds, both natural and synthetic, are explained in terms of structure and mechanism of action. The main uses of these antifungal compounds and their degree of effectiveness are detailed. State-of-the-art studies have shown a clear trend of increasing studies on incorporating antifungals in biodegradable materials since 2000. The bibliometric networks showed studies on active packaging, biodegradable polymers, films, antimicrobial and antifungal activities, essential oils, starch and polysaccharides, nanocomposites, and nanoparticles. The combination of the development of bio-based and biodegradable materials with the ability to control fungal growth promotes both sustainability and the innovative enhancement of the packaging sector.

Preparation of edible antibacterial films based on corn starch /carbon nanodots for bioactive food packaging

Packaging plays an important role in protecting food from environmental impacts. However, traditional petroleum-based packaging has difficulty in meeting the antimicrobial and antioxidant requirements of prepared foods. This study introduced carbon dots (CDs), prepared by using carrot as a precursor, into corn starch (CS) to construct a bio-friendly composite film with high freshness retention properties. The scavenging of DPPH radicals reached 92.77 % at a CDs concentration of 512 µg/mL, and the antimicrobial activity of CS/5% CDs against Escherichia coli and Staphylococcus aureus was increased to 99.9 %. Notably, the homogeneous doping of CDs creates a dense surface and high carbon content inside the film, which promotes the elasticity and thermal stability of the composite film. Finally, we encapsulated deep-fried meatballs in CS-CDs films. The results showed that the CS-CDs films effectively protected the quality of deep-fried meatballs, and have excellent potential for application in food preservation.

Development of high barrier-coated white cardboard for fruit preservation

Environment-friendly and biodegradable packaging materials have attracted widespread attention. Development of green solutions to extend the fruit shelf life and address fruit preservation thus has a far-reaching impact. In this study, high-barrier white cardboard (WC) was prepared by a facile coating method. Compared with the WC substrate, the WVP value of the polyvinylidene chloride (PVDC) emulsion-coated WC (3.46 × 10-11 g m m-2 s-1 kPa-1) decreased 73.8% and the OP value (14.8 cm3 m-2 day-1·Pa-1) decreased 61.9%. In addition, the mechanical properties of the PVDC emulsion-coated WC increased significantly. The weight loss rate and decay rate of the stored fruits packaged with PVDC emulsion-coated WC decreased by about 5%. The high barrier PVDC emulsion-coated WC with excellent mechanical properties, good barrier effect, and preservation function was successfully prepared. Benefitting from these investigated characteristics, the obtained coated WC can be used to package fruits to reduce water loss and delay ripening, and thus extend their shelf life, exhibiting a favorable effect on blueberry and grape storage. Overall, the fabricated eco-friendly coated white cardboard has shown great potential for biodegradable packaging applications. We believe the current work presents an approach to address perishable fruit preservation and provide a supplement alternative.

Quantum dots as advanced nanomaterials for food quality and safety applications: A comprehensive review and future perspectives

The importance of food quality and safety lies in ensuring the best product quality to meet consumer demands and public health. Advanced technologies play a crucial role in minimizing the risk of foodborne illnesses, contamination, drug residue, and other potential hazards in food. Significant materials and technological advancements have been made throughout the food supply chain. Among them, quantum dots (QDs), as a class of advanced nanomaterials with unique physicochemical properties, are progressively demonstrating their value in the field of food quality and safety. This review aims to explore cutting-edge research on the different applications of QDs in food quality and safety, including encapsulation of bioactive compounds, detection of food analytes, food preservation and packaging, and intelligent food freshness indicators. Moreover, the modification strategies and potential toxicities of diverse QDs are outlined, which can affect performance and hinder applications in the food industry. The findings suggested that QDs are mainly used in analyte detection and active/intelligent food packaging. Various food analytes can be detected using QD-based sensors, including heavy metal ions, pesticides, antibiotics, microorganisms, additives, and functional components. Moreover, QD incorporation aided in improving the antibacterial and antioxidant activities of film/coatings, resulting in extended shelf life for packaged food. Finally, the perspectives and critical challenges for the productivity, toxicity, and practical application of QDs are also summarized. By consolidating these essential aspects into this review, the way for developing high-performance QD-based nanomaterials is presented for researchers and food technologists to better capitalize upon this technology in food applications.

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.