Titanium dioxide (TiO2) for the manufacture of multifunctional active food packaging films

Antimicrobial nanoparticle-containing food packaging films for controlling Listeria spp.: An overview

Bacteria of the genus Listeria are ubiquitous in nature and are found in various food products and food processing facilities. The species Listeria monocytogenes is a food-borne pathogen that causes listeriosis with a high fatality rate. For the prevention and control of listeriosis, the identification of effective antilisterial compounds is desirable. The number of investigations on nanoparticles (NPs) with antimicrobial activity has increased in recent years. In this context, green nanotechnology is a field of science that focuses on the synthesis of NPs through biological pathways using a wide range of microorganisms and plant extracts, which has led to the biofabrication of novel antimicrobial agents that have demonstrated remarkable potential against pathogenic bacteria. In this review, in vitro studies of the inhibitory action of antimicrobial NPs obtained by green biosynthesis, including silver, gold, zinc, zinc oxide, copper, palladium, and selenium NPs, on the growth of Listeria spp. were comprehensively summarized. This review mainly highlights antimicrobial NPs in biopolymer films against L. monocytogenes. Furthermore, studies on NPs in biopolymer-based functional food packaging films against L. monocytogenes are listed. Finally, safety considerations are indicated. This review provides an overview of the antilisterial activity of bio-based antimicrobial NPs and the potential of nanotechnology as an innovative technology for the development of food packaging films containing antimicrobial NPs to control Listeria spp.

Recent research progress on locust bean gum (LBG)-based composite films for food packaging

In recent years, there has been an increasing demand for biodegradable/edible biopolymer food packaging films to mitigate the environmental damage caused by petroleum-based plastic food packaging. In this context, locust bean gum (LBG) or carob gum is a galactomannan extracted from the endosperm of carob (Ceratonia siliqua) seeds. Due to its excellent film-forming properties, LBG has been widely used in the development of biodegradable food packaging films. In addition, due to the rich hydroxyl groups in LBG, it can produce synergistic gelation with many biopolymers to form blended films, and LBG has also been used in combination with many additives to form composite films with excellent antibacterial, antioxidant, and barrier properties, including various nanoparticles and plant extracts. Functional composite films based on LBG can effectively extend the shelf life and monitor the freshness of fruits, meats, and other processed foods. Therefore, in this work, we briefly introduce the chemical properties and application progress of LBG, focusing on the performance of various composite LBG food packaging films. Finally, the practical applications of LBG-based composite films and edible coatings in food preservation are summarized.

Eco-friendly nanocomposite biofilm based on sage seed gum/gelatin/TiO2: Fabrication and characterization

In the current study, the sage seed gum/gelatin-TiO2 (SG/Ge-TiO2) nanocomposite films were prepared. Their physical, mechanical, chemical, barrier, surface, structural, and microbial characteristics are determined as a function of different ratios of sage seed gum (SG) to gelatin (1 to 2, 2 to 1 and 1 to 1) and different concentrations of TiO2 nanoparticles (0, 2, 4 % based on biopolymer (w/v)). The results indicated increases in the tensile strength, elongation at break, thickness, brightness (L*), whiteness index (WI), and contact angle, as gelatin content and concentration of TiO2 nanoparticles increase. In addition, the increases of TiO2 nanoparticles and the increased content of SG lead to an increase in the surface roughness of the films. As the gelatin content and the concentration of TiO2 nanoparticles increased, the barrier characteristics against water vapor, oxygen, and light increased, so that the water vapor, oxygen, and light permeability in the SG 1-Ge 2-4 % film decreased by 66.93 %, 80.89 %, and 47.43 %, respectively, compared to the SG 2 Ge 1-0 % film. According to the results of structural and thermal investigation, the crystallinity degree in the films increased as the gelatin content and the concentration of TiO2 nanoparticles increased, resulting in the enhanced thermal stability of the film. The addition of TiO2 nanoparticles brought about antimicrobial characteristics in the film, with no significant effect on the antioxidant activity and total phenol content (p > 0.05). The results indicated that SG-Ge-TiO2 bionanocomposite films (especially SG 1-Ge 2-4 %) can be considered a suitable option for active food packaging as well as medical applications (e.g. active wound adhesive) due to its favorable characteristics.

Prospects and challenges of nanomaterials in sustainable food preservation and packaging: a review

Nanomaterials play a pivotal role in food preservation and its safety, offering ingenious solutions for sustainable food packaging. Nanomaterials enable the creation of packaging materials having unique functional properties. It not only extends the shelf life of the foods by releasing preservatives but also enhances food safety by preventing microbial contamination or food spoilage. In this review, we aim to provide an overview of the various applications of nanotechnology in food packaging, highlighting its key advantages. We also delve into the safety considerations and regulatory issues involved in developing nanotechnology-based food packaging materials. Additionally, advancements in the field of nanotechnology-based packaging have the potential to create safer, more sustainable, and high-quality packaging with greater functionality that delivers essential benefits to manufacturers and consumers.

Antimicrobial effects of pulsed light activated TiO2-Polylactic acid film

A study was conducted to evaluate the antimicrobial effect of TiO2 incorporated polylactic acid (PLA) films, activated by pulsed light (PL). TiO2-PLA films with 0, 0.5, 5, 10, and 20 % TiO2/PLA ratio were developed by the solvent casting method. Populations of Escherichia coli and Listeria on film surfaces were determined after the films were PL-treated in three ways: PL treatment on the inoculated film surface; PL treatment from the reverse side of the inoculated film surface; PL treatment before the inoculation on the film surface. A 5 s PL treatment reduced E. coli populations on PLA film from 6.2 to 2.5 log CFU/cm2 and on TiO2-PLA film from 6.2 to 1.1 log CFU/cm2, indicating the combined antibacterial effect of PL and TiO2. Light-activated TiO2-PLA films maintained antibacterial activity against E. coli and L. innocua for 2 h after the 5 s PL treatment, as the activated TiO2-PLA films were still able to reduce bacterial populations by up to 2.5 log CFU/cm2. These findings suggest that pre-activated TiO2-PLA films have potential for packaging foods that are sensitive to UV light.

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.

Application of seed mucilage as functional biopolymer in meat product processing and preservation

Meat products consumption is rising globally, but concerns about sustainability, fat content, and shelf life. Synthetic additives and preservatives used for extending the shelf life of meat often carry health and environmental drawbacks. Seed mucilage, natural polysaccharides, possesses unique functional properties like water holding, emulsifying, and film forming, offering potential alternatives in meat processing and preservation. This study explores the application of seed mucilage from diverse sources (e.g., flaxseed, psyllium, basil) in various meat and meat products processing and preservation. Mucilage's water-holding and emulsifying properties can potentially bind fat and decrease the overall lipid content in meat and meat-based products. Moreover, antimicrobial and film-forming properties of mucilage can potentially inhibit microbial growth and reduce oxidation, extending the shelf life. This review emphasizes the advantages of incorporating mucilage into processing and coating strategies for meat and seafood products.

Nanotechnology in food packaging materials: role and application of nanoparticles

Global concerns about food security, driven by rising demand, have prompted the exploration of nanotechnology as a solution to enhance food supply. This shift comes in response to the limitations of conventional technologies in meeting the ever-increasing demand for food products. Consequently, nanoparticles play a crucial role in enhancing food production, preservation, and extending shelf life by imparting exceptional properties to materials. Nanoparticles and nanostructures with attributes like expansive surface area and antimicrobial efficacy, are versatile in both traditional packaging and integration into biopolymer matrices. These distinctive qualities contribute to their extensive use in various food sector applications. Hence, this review explores the physicochemical properties, functions, and biological aspects of nanoparticles in the context of food packaging. Furthermore, the synergistic effect of nanoparticles with different biopolymers, alongside its different potential applications such as food shelf-life extenders, antimicrobial agents and as nanomaterials for developing smart packaging systems were summarily explored. While the ongoing exploration of this research area is evident, our review highlights the substantial potential of nanomaterials to emerge as a viable choice for food packaging if the challenges regarding toxicity are carefully and effectively modulated.

Nanofillers in Novel Food Packaging Systems and Their Toxicity Issues

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

Smart food packaging: Recent advancement and trends

Food packaging plays an important role in protecting the safety and quality of food products and enables communication with consumers. With the improved consumers' awareness of safety and quality of food products, the changes in consumers' lifestyle, and the growing demand for transparency of food products along the supply chain, food packaging technologies have evolved from only providing the four fundamental functions (i.e., protection and preservation, containment, communication and marketing, and convenience) to possessing additional functions including active modification of the inside microenvironment (i.e., active packaging) and monitoring the safety and quality of products in real-time (i.e., intelligent packaging). A variety of active and intelligent packaging systems have been developed to better protect and monitor the quality and safety of food products during the past several decades. Recently, advanced versions of smart packaging technologies, such as smart active packaging and smart intelligent packaging technologies have also been developed to enhance the effectiveness of conventional smart packaging systems. Additionally, smart packaging systems that harvest the advantages of both active packaging and intelligent packaging have also been developed. In this chapter, a brief overview of smart packaging technologies was provided. Specific technologies being covered include conventional smart packaging technologies and advanced smart packaging technologies, such as smart active packaging, smart intelligent packaging and dual-function smart packaging.

Advances in sustainable food packaging applications of chitosan/polyvinyl alcohol blend films

Researchers are addressing environmental concerns related to petroleum-based plastic packaging by exploring biopolymers from natural sources, chemical synthesis, and microbial fermentation. Despite the potential of individual biopolymers, they often exhibit limitations like low water resistance and poor mechanical properties. Blending polymers emerges as a promising strategy to overcome these challenges, creating films with enhanced performance. This review focuses on recent advancements in chitosan/polyvinyl alcohol (PVA) blend food packaging films. It covers molecular structure, properties, strategies for performance improvement, and applications in food preservation. The blend's excellent compatibility and intermolecular interactions make it a promising candidate for biodegradable films. Future research should explore large-scale thermoplastic technologies and investigate the incorporation of additives like natural extracts and nanoparticles to enhance film properties. Chitosan/PVA blend films offer a sustainable alternative to petroleum-based plastic packaging, with potential applications in practical food preservation.

Construction of photocatalytic coating for alleviating the shriveling of postharvest fruit cucumber after simulated transportation

The shriveling of fruit cucumber was commonly occurred during supply chain, photocatalyst exposed to UV light can endow the coatings with ethylene removal capacity to reduce the respiration of fruit and water loss. The study developed a novel photodynamic technology responsive photocatalytic coating with exceptional ultraviolet (UV) photocatalytic degradation of ethylene ability to decay the shriveling of postharvest fruit cucumber during supply chain. This coating involved the integration of Carbon dots (CDs)-loaded nano ZnO and the skillful selection of pullulan (Pul) and apple pectin (AP) matrix. The CDs/ZnO coatings boasted an impressive array of photocatalytic degradation of ethylene and adhesion properties, including high ethylene removal rates of 32.04 % in 60 min UV light stimulation. The decrease of cell-wall strength, degradation of the cell wall polysaccharides and water loss resulted in cucumber shriveling. Compared with CK sample, after UV-CDs/ZnO coating treatment, the higher firmness and cell wall polysaccharides were found in cucumbers with lower cell wall degrading enzymes activities, weight loss and water movement, which was associated with the decrease of respiration and ethylene accumulation. The UV-CDs/ZnO coatings possessed promising potential for alleviating the shriveling of postharvest fruit cucumber and applications in fruits preservation in the future.

Sweet cherry tree (Prunus avium) exudate gum-based film modification in a photoreactor: Effects of hydrogen peroxide oxidation, UV irradiation, and TiO2 nanoparticles

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32-4.72 (×10-10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.

Novel chitosan-based smart bio-nanocomposite films incorporating TiO2 nanoparticles for white bread preservation

Chitosan (CS)-based bio-nanocomposite food packaging films were prepared via solvent-casting method by incorporating a unique combination of additives and fillers, including polyvinyl alcohol (PVA), glycerol, Tween 80, castor oil (CO), and nano titanium dioxide (TiO2) in various proportions to enhance film properties. For a comprehensive analysis of the synthesized films, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile testing, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and UV-vis spectrophotometry were employed. Furthermore, the antimicrobial efficacy of the films against S. aureus, E. coli, and A. niger was examined to assess their potential to preserve food from foodborne pathogens. The results claimed that the inclusion of castor oil and TiO2 nanoparticles considerably improved antimicrobial properties, UV-vis light barrier properties, thermal stability, optical transparency, and mechanical strength of the films, while reducing their water solubility, moisture content, water vapor and oxygen permeability. Based on the overall analysis, CS/PVA/CO/TiO2-0.3 film can be selected as the optimal one for practical applications. Furthermore, the practical application of the optimum film was evaluated using white bread as a model food product. The modified film successfully extended the shelf life of bread to 10 days, surpassing the performance of commercial LDPE packaging (6 days), and showed promising attributes for applications in the food packaging sector. These films exhibit superior antimicrobial properties, improved mechanical strength, and extended shelf life for food products, marking a sustainable and efficient alternative to conventional plastic packaging in both scientific research and industrial applications.

Nanometals incorporation into active and biodegradable chitosan films

This study investigates the effects of incorporating ZnO, TiO2, and colloidal Ag nanoparticles on the antioxidant, antimicrobial, and physical properties of biodegradable chitosan films. The research focuses on addressing the growing demand for sustainable packaging solutions that offer efficient food preservation while mitigating environmental concerns. In this investigation, the physical properties including thickness, water content, solubility, swelling degree, tensile strength, and elasticity of the chitosan films were examined. Additionally, the samples were analyzed for total polyphenol content, antimicrobial activity, and antioxidant capacity. Notably, the incorporation of ZnO nanoparticles led to the lowest water content and highest strength values among the tested films. Conversely, the addition of colloidal Ag nanoparticles resulted in films with the highest antioxidant capacities (DPPH: 32.202 ± 1.631 %). Remarkably, antimicrobial tests revealed enhanced activity with the inclusion of colloidal silver nanoparticles, yet the most potent antimicrobial properties were observed in films containing ZnO (E.coli: 2.0 ± 0.0 mm; MRSA: 2.0 ± 0.5 mm). The findings of this study hold significant implications for the advancement of edible biodegradable films, offering potential for more efficient food packaging solutions that address environmental sustainability concerns. By elucidating the effects of nanoparticle incorporation on film properties, this research contributes to the ongoing discourse surrounding sustainable packaging solutions in the food industry.

Chitosan-Based Films Blended with Tannic Acid and Moringa Oleifera for Application in Food Packaging: The Preservation of Strawberries (Fragaria ananassa)

Biobased plastics provide a sustainable alternative to conventional food packaging materials, thereby reducing the environmental impact. The present study investigated the effectiveness of chitosan with varying levels of Moringa oleifera seed powder (MOSP) and tannic acid (TA). Chitosan (CS) biocomposite films with tannic acid acted as a cross-linker, and Moringa oleifera seed powder served as reinforcement. To enhance food packaging and film performance, Moringa oleifera seed powder was introduced at various loadings of 1.0, 3.0, 5.0, and 10.0 wt.%. Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analyses were performed to study the structure and morphology of the CS/TA/MOSP films. The scanning electron microscopy results confirmed that chitosan/TA with 10.0 wt.% of MOSP produced a lightly miscible droplet/matrix structure. Furthermore, mechanical properties, swelling, water solubility, optical barrier, and water contact angle properties of the film were also calculated. With increasing Moringa oleifera seed powder contents, the biocomposite films' antimicrobial and antifungal activity increased at the 10.0 wt.% MOSP level; all of the observed bacteria [Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Aspergillus niger (A. niger), and Candida albicans (C. albicans)] had a notably increased percentage of growth. The film, with 10.0 wt.% MOSP content, effectively preserves strawberries' freshness, making it an ideal food packaging material.

Advanced technologies in biodegradable packaging using intelligent sensing to fight food waste

The limitation of conventional packaging in demonstrating accurate and real-time food expiration dates leads to food waste and foodborne diseases. Real-time food quality monitoring via intelligent packaging could be an effective solution to reduce food waste and foodborne illnesses. This review focuses on recent technological advances incorporated into food packaging for monitoring food spoilage, with a major focus on paper-based sensors and their combination with smartphone. This review paper offers a comprehensive exploration of advanced macromolecular technologies in biodegradable packaging, a general overview of paper-based probes and their incorporation into food packaging coupled with intelligent sensing mechanisms for monitoring food freshness. Given the escalating global concerns surrounding food waste, our manuscript serves as a pivotal resource, consolidating current research findings and highlighting the transformative potential of these innovative packaging solutions. We also highlight the current intelligent paper-based food freshness sensors and their various advantages and limitations. Examples of implementation of paper-based sensors/probes for food storage and their accuracy are presented. Finally, we examined how intelligent packaging can be an alternative to reduce food waste. Several technologies discussed here have good potential to be used in food packaging for real-time food monitoring, especially when combined with smartphone diagnosis.

Enhanced properties of gelatin films incorporated with TiO2-loaded reduced graphene oxide aerogel microspheres for active food packaging applications

The synergistic effect of graphene sheets and titanium dioxide nanoparticles (TiO2) hybrid fillers can improve the antibacterial, mechanical, and barrier properties of gelatin (GL), making it more suitable to be used in the food packaging application. However, the uneven dispersion and aggregation of the hybrid fillers restrict its performance for further application. In order to achieve the above superior properties, reduced graphene oxide aerogel microspheres (rGOAMs) loaded with TiO2 (rGOAMs@TiO2) were successfully prepared using one-step hydrothermal process by reducing titanium sulfate into TiO2 on the framework of rGOAMs, followed by effective dispersion in the GL matrix to form nanocomposites (rGOAMs@TiO2/GL) through simultaneous ultrasonication and mechanical stirring, as well as an ultrasonic cell grinder process. Incorporating a mere 0.8 wt% of rGOAMs@TiO2 effectively improved the mechanical, antibacterial, UV light barrier, thermal stability, hydrophobicity, and water vapor barrier properties of the GL. Compared with the composites made of rGOAMs, TiO2, and GL (rGOAMs/TiO2/GL), rGOAMs@TiO2/GL composites showed stronger filler-matrix interactions, better filler dispersion, and lower TiO2 particle aggregation, suggesting superiority compared to rGOAMs/TiO2/GL composites at the same filler content. This innovative method of mixing GL with rGOAMs@TiO2 holds great promise for enhancing the suitability of GL in active food packaging applications.

Recent advances in the use of composite titanium dioxide nanomaterials in the food industry

Titanium dioxide (TiO2 ) nanomaterials have attracted significant attention due to their good biocompatibility and potential for multifunctional applications. In the last few years, there has been growing interest in the use of TiO2 nanomaterials in the food industry. However, a systematic review of the synthesis methods, properties, and applications of TiO2 nanomaterials in the food industry is lacking. In this review, we provide a summary of the synthesis and properties of TiO2 nanomaterials and their composites, with a focus on their applications in the food industry. We also discuss the potential benefits and risks of using TiO2 nanomaterials in food applications. This review aims to promote food innovation and improve food quality and safety.

Photocatalytic titanium dioxide reduces postharvest decay of nectarine fruit packaged in different materials through modulating central carbon and energy metabolisms

The capacity of titanium dioxide (TiO2) photocatalysis photocatalytic reactor to prevent and control pathogen infection in nectarine fruit packed in laminated nylon/LDPE, low density polyethylene and microperforated LDPE films was evaluated. Results showed that TiO2 combined with microperforated LDPE packaging (TPL) exhibited superior inhibition of microbial growth, reducing total viable counts by 4.18 log CFU g-1 and yeast and mold counts by 3.20 log CFU g-1, compared to microperforated LDPE packaging alone. TiO2 photocatalysis primed the defense systems in nectarine fruit packed in microperforated LDPE, improving the activity of defense-related enzymes. Metabolomics analysis indicated that l-aspartate, oxaloacetate, and succinic acid involved in central carbon metabolism including the glycolysis and tricarboxylic acid cycle pathways, were significantly upregulated by TPL. TiO2 increased the activity of energy metabolism-related enzymes, adenosine triphosphate, adenosine diphosphate, and energy charge levels to provide adequate energy, thus reducing fruit decay.

TiO2 incorporated into a blend of biopolymeric matrices improves film properties and affects the postharvest conservation of papaya fruits under UV light

This work investigated the properties of chitosan-cassava starch biopolymeric films containing nanometric photoactive TiO2 particles for use in postharvest conservation of papaya fruits under UV light at a temperature of 15 ± 1 °C and a relative humidity of 90 ± 1 % for 24 days. Starch-chitosan blend films showed intermediate hydrophobicity and improved mechanical properties. The addition of 1 % TiO2 into the polymeric matrix of starch/chitosan (1:1) further improved the mechanical properties with solubility of 16.04 ± 0.41 %, visible transmittance of 31.76 ± 1.58 %, and reduced UV transmittance of more than 97 %. However, the addition of TiO2 exceeding 1 % led to the formation of agglomerates and excessive reduction in film transparency. UV exposure damaged the fruit peel and resulted in a higher weight loss. In contrast, the addition of 1 % TiO2 to the blend reduced the weight loss in light and dark by 7.12 ± 1.57 % and 5.27 ± 0.31 % respectively, and delayed fruit ripening.

Advances in transglutaminase cross-linked protein-based food packaging films; a review

Pushed by the environmental pollution and health hazards of plastic packaging, the development of biodegradable food packaging films (FPFs) is a necessary and sustainable trend for social development. Most protein molecules have excellent film-forming properties as natural polymer matrices, and the assembled films have excellent barrier properties, but show defects such as low water resistance and poor mechanical properties. In order to improve the performance of protein-based films, transglutaminase (TG) is used as a safe and green cross-linking (CL) agent. This work covers recent developments on TG cross-linked protein-based FPFs, mainly comprising proteins of animal and plant origin, including gelatin, whey protein, zein, soy proteins, bitter vetch protein, etc. The chemical properties and reaction mechanism of TG are briefly introduced, focusing on the effects of TG CL on the physicochemical properties of different protein-based FPFs, including barrier properties, water resistance, mechanical properties and thermal stability. It is concluded that the addition of TG can significantly improve the physical and mechanical properties of protein-based films, mainly improving their water resistance, barrier, mechanical and thermal properties. It is worth noting that the effect of TG on the properties of protein-based films is not only related to the concentration of TG added, but also related to CL temperature and other factors. Moreover, TG can also be used in combination with other strategies to improve the properties of protein-based films.

Facile Strategy for Boosting of Inorganic Fillers Retention in Paper

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO3) as a filler to boost paper's brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO2 nanospheres, TiO2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper.

Polysaccharides and proteins based bionanocomposites as smart packaging materials: From fabrication to food packaging applications a review

Food industry is the biggest and rapidly growing industries all over the world. This sector consumes around 40 % of the total plastic produced worldwide as packaging material. The conventional packaging material is mainly petrochemical based. However, these petrochemical based materials impose serious concerns towards environment after its disposal as they are nondegradable. Thus, in search of an appropriate replacement for conventional plastics, biopolymers such as polysaccharides (starch, cellulose, chitosan, natural gums, etc.), proteins (gelatin, collagen, soy protein, etc.), and fatty acids find as an option but again limited by its inherent properties. Attention on the initiatives towards the development of more sustainable, useful, and biodegradable packaging materials, leading the way towards a new and revolutionary green era in the food sector. Eco-friendly packaging materials are now growing dramatically, at a pace of about 10-20 % annually. The recombination of biopolymers and nanomaterials through intercalation composite technology at the nanoscale demonstrated some mesmerizing characteristics pertaining to both biopolymer and nanomaterials such as rigidity, thermal stability, sensing and bioactive property inherent to nanomaterials as well as biopolymers properties such as flexibility, processability and biodegradability. The dramatic increase of scientific research in the last one decade in the area of bionanocomposites in food packaging had reflected its potential as a much-required and important alternative to conventional petroleum-based material. This review presents a comprehensive overview on the importance and recent advances in the field of bionanocomposite and its application in food packaging. Different methods for the fabrication of bionanocomposite are also discussed briefly. Finally, a clear perspective and future prospects of bionanocomposites in food packaging were presented.

Evaluation of the use of Idesia polycarpa Maxim protein coating to extend the shelf life of European sweet cherries

Idesia polycarpa Maxim protein was used as a substrate to prepare a novel food packaging material with bioactive functions for encapsulating and extending the postharvest shelf life of sweet cherries. The film-forming solution was prepared from a mixture of Idesia polycarpa Maxim protein, glycerol, and gelatin, and was cast to form a film at room temperature and evaluated for mechanical, optical, structural, crystallinity, thermal properties, morphology, and antioxidant activity. Idesia polycarpa Maxim protein composite film solution was applied as an edible coating on sweet cherries and evaluated for changes in physical and biochemical parameters of sweet cherries in storage at 20°C and 50% relative humidity for 9 days. The results showed that the film tensile strength increased from 0.589 to 1.981 Mpa and the elongation at break increased from 42.555% to 58.386% with the increase of Idesia polycarpa Maxim protein concentration. And in the in vitro antioxidant assay, IPPF-4.0% was found to have the best antioxidant activity, with scavenging rates of 65.11% ± 1.19%, 70.74% ± 0.12%, and 90.96% ± 0.49% for DPPH radicals, ABTS radicals, and hydroxyl radicals, respectively. Idesia polycarpa Maxim protein coating applied to sweet cherries and after storage at 20°C and 50% relative humidity for 9 days, it was found that the Idesia polycarpa Maxim protein coating significantly reduced the weight loss (54.82% and 34.91% in the Control and Coating-2.5% groups, respectively) and the loss of ascorbic acid content (16.47% and 37.14% in the Control and Coating-2.5% groups, respectively) of the sweet cherries, which can effectively extend the aging of sweet cherry fruits and prolong their shelf life. The developed protein film of Idesia polycarpa Maxim with antioxidant activity can be used as a new food packaging material in the food industry.

Starch-gelatin blend films: A promising approach for high-performance degradable food packaging

Packaging plays a vital role in safeguarding food from environmental factors and contamination. However, the overuse and improper disposal of non-biodegradable plastic packaging materials have led to environmental concerns and health risks. To address these challenges, the development of degradable food packaging films is crucial. Biodegradable polymers, including natural biopolymers like starch (ST) and gelatin (GE), have emerged as promising alternatives to traditional plastics. This review focuses on the utilization of ST-GE blends as key components in composite films for food packaging applications. We discuss the limitations of pure ST-GE films and explore methods to enhance their properties through the addition of plasticizers, cross-linkers, and nanoparticles. The blending of ST-GE, facilitated by their good miscibility and cross-linking potential, is highlighted as a means to improve film performance. The review also examines the impact of various additives on the properties of ST-GE blend films and summarizes their application in food preservation. By providing a comprehensive overview of ST-GE hybrid systems, this study aims to contribute to the advancement of sustainable and effective food packaging solutions.

Natural food preservation with ginger essential oil: Biological properties and delivery systems

Recently, the increasing demand from consumers for preservative-free or naturally preserved foods has forced the food industry to turn to natural herbal and plant-derived preservatives rather than synthetic preservatives to produce safe foods. Essential oils derived from ginger (Zingiber officinale Roscoe) are widely known for their putative health-promoting bioactivities, and this paper covers their extraction methods, chemical composition, and antibacterial and antioxidant activities. Especially, the paper reviews their potential applications in food preservation, including nanoemulsions, emulsions, solid particle encapsulation, and biodegradable food packaging films/coatings. The conclusion drawn is that ginger essential oil can be used not only for direct food preservation but also encapsulated using various delivery forms such as nanoemulsions, Pickering emulsions, and solid particle encapsulation to improve its release control ability. The film of encapsulated ginger essential oil has been proven to be superior to traditional methods in preserving foods such as bread, meat, fish, and fruit.

Tannic Acid and Ca2+ Double-Crosslinked Alginate Films for Passion Fruit Preservation

In this study, the interaction of different concentrations of tannic acid (TA) (10%, 20%, and 30% w/w) and Ca2+ with alginate (SA) was utilized to create double-crosslinked SA films. The resulting films were evaluated for their optical, mechanical, water resistance, and barrier properties, and their microstructure and intermolecular interactions were also characterized. The SA films containing 20% TA showed the best mechanical properties, with an observed increase in tensile strength of 22.54%. In terms of water vapor permeability, the SA film containing 30% TA exhibited the highest barrier property, which was 25.36% higher than that of the pure SA film. Moreover, TA demonstrated a strong UV absorption ability, resulting in a nearly 0% UV transmittance of the SA film at 280 nm. It can be seen that SA films containing 20% TA have excellent barrier and mechanical properties, and the development of such films will be applied to the storage and packaging of fresh food. It is worth noting that this work also investigated the effect of SA coatings containing different concentrations of TA on the preservation of passion fruits for 7 days. The results revealed that passion fruits treated with SA coatings containing a 30% TA concentration maintained a better appearance on the 7th day and had the lowest weight loss and crumpling indices of approximately 8.98% and 2.17, respectively, compared to the other treatment groups. Therefore, based on the overall results, the addition of 30% TA to SA coatings proved to be more effective and can be considered a promising approach for delaying fruit senescence and decay.

Innovations in Food Packaging for a Sustainable and Circular Economy

Packaging is fundamental to maintaining the quality of food, but its contribution with a negative footprint to the environment must be completely changed worldwide to reduce pollution and climate change. Innovative and sustainable packaging and new strategies of reutilization are necessary to reduce plastic waste accumulation, maintain food quality and safety, and reduce food losses and waste. The purpose of this chapter is to present innovations in food packaging for a sustainable and circular economy. First, to present the eco-design packaging approach as well as new strategies for recycled or recyclable materials in food packaging. Second, to show current trends in new packaging materials developed from the use of agro-industrial wastes as well as new methods of production, including 3D/4D printing, electrostatic spinning, and the use of nanomaterials.

Application of a Chitosan-Cinnamon Essential Oil Composite Coating in Inhibiting Postharvest Apple Diseases

The purpose of this study was to explore the film-forming properties of cinnamon essential oil (CEO) and chitosan (CS) and the effect of their composite coating on postharvest apple diseases. The results demonstrated that the composite coating exhibits favorable film-forming properties at CEO concentrations below 4% (v/v). The effectiveness of the composite coating in disease control can be attributed to two factors: the direct inhibitory activity of CEO against pathogens in vitro and the induced resistance triggered by CS on the fruits. Importantly, the incorporation of CEO did not interfere with the induction of resistance by CS in harvested apples. However, it is noteworthy that the inhibitory effect of the CS-CEO composite coating on apple diseases diminished over time. Therefore, a key aspect of enhancing the preservation ability of fruits is improving the controlled release properties of CEO within CS coatings. This will enable a sustained and prolonged antimicrobial effect, thereby bolstering the fruit preservation capabilities of the composite coatings.

Developing a Prolamin-Based Gel for Food Packaging: In-Vitro Assessment of Cytocompatibility

Growing environmental concerns drive efforts to reduce packaging waste by adopting biodegradable polymers, coatings, and films. However, biodegradable materials used in packaging face challenges related to barrier properties, mechanical strength, and processing compatibility. A composite gel was developed using biodegradable compounds (prolamin, d-mannose, citric acid), as a coating to increase the oxygen barrier of food packaging materials. To improve gel stability and mechanical properties, the gels were physically cross-linked with particles synthesized from tetraethyl orthosilicate and tetramethyl orthosilicate precursors. Additionally, biocompatibility assessments were performed on human keratinocytes and fibroblasts, demonstrating the safety of the gels for consumer contact. The gel properties were characterized, including molecular structure, morphology, and topography. Biocompatibility of the gels was assessed using bioluminescent ATP assay to detect cell viability, lactate dehydrogenase assay to determine cell cytotoxicity, and a leukocyte stimulation test to detect inflammatory potential. A composite gel with strong oxygen barrier properties in low-humidity environments was prepared. Increasing the silane precursor to 50 wt% during gel preparation slowed degradation in water. The addition of citric acid decreased gel solubility. However, higher precursor amounts increased surface roughness, making the gel more brittle yet mechanically resistant. The increase of precursor in the gel also increased gel viscosity. Importantly, the gels showed no cytotoxicity on human keratinocytes or fibroblasts and had no inflammatory effects on leukocytes. This composite gel holds promise for oxygen barrier food packaging and is safe for consumer contact. Further research should focus on optimizing the stability of the oxygen barrier in humid environments and investigate the potential sensitizing effects of biodegradable materials on consumers.

The Mechanisms of Plastic Food-Packaging Monomers' Migration into Food Matrix and the Implications on Human Health

The development of packaging technology has become a crucial part of the food industry in today's modern societies, which are characterized by technological advancements, industrialization, densely populated cities, and scientific advancements that have increased food production over the past 50 years despite the lack of agricultural land. Various types of food-packaging materials are utilized, with plastic being the most versatile. However, there are certain concerns with regards to the usage of plastic packaging because of unreacted monomers' potential migration from the polymer packaging to the food. The magnitude of monomer migration depends on numerous aspects, including the monomer chemistry, type of plastic packaging, physical-chemical parameters such as the temperature and pH, and food chemistry. The major concern for the presence of packaging monomers in food is that some monomers are endocrine-disrupting compounds (EDCs) with a capability to interfere with the functioning of vital hormonal systems in the human body. For this reason, different countries have resolved to enforce guidelines and regulations for packaging monomers in food. Additionally, many countries have introduced migration testing procedures and safe limits for packaging monomer migration into food. However, to date, several research studies have reported levels of monomer migration above the set migration limits due to leaching from the food-packaging materials into the food. This raises concerns regarding possible health effects on consumers. This paper provides a critical review on plastic food-contact materials' monomer migration, including that from biodegradable plastic packaging, the monomer migration mechanisms, the monomer migration chemistry, the key factors that affect the migration process, and the associated potential EDC human health risks linked to monomers' presence in food. The aim is to contribute to the existing knowledge and understanding of plastic food-packaging monomer migration.

Interaction of Nanomaterials with Cells and Tissues

Nanomaterials have gained enormous importance in biomedicine in recent years, both in basic and applied sciences [...].

Study of Ethylene-Removing Materials Based on Eco-Friendly Composites with Nano-TiO2

Ethylene is a phytohormone that is responsible of fruit and vegetable ripening. TiO2 has been studied as a possible solution to slowing down unwanted ripening processes, due to its photocatalytic capacity which enables it to remove ethylene. Thus, the objective of this study was to develop nanocomposites based on two types of eco-friendly materials: Mater-Bi® (MB) and poly(lactic acid) (PLA) combined with nano-TiO2 for ethylene removal and to determine their ethylene-removal capacity. First, a physical-chemical characterization of nano-TiO2 of different particle sizes (15, 21, 40 and 100 nm) was done through structural and morphological analysis (DRX, FTIR and TEM). Then, its photocatalytic activity and the ethylene-removal capacity were determined, evaluating the effects of time and the type of light irradiation. With respect to the analysis of TiO2 nanoparticles, the whole samples had an anatase structure. According to the photocatalytic activity, nanoparticles of 21 nm showed the highest activity against ethylene (~73%). The results also showed significant differences in ethylene-removal activity when comparing particle size and type and radiation time. Thus, 21 nm nano-TiO2 was used to produce nanocomposites through the melt-extrusion process to simulate industrial processing conditions. With respect to the nanocomposites' ethylene-removing properties, there were significant differences between TiO2 concentrations, with samples with 5% of active showed the highest activity (~57%). The results obtained are promising and new studies are needed to focus on changes in material format and the evaluation in ethylene-sensitive fruits.

Metal-Based Nanoparticles in Food Packaging and Coating Technologies: A Review

Food security has continued to be a topic of interest in our world due to the increasing demand for food. Many technologies have been adopted to enhance food supply and narrow the demand gap. Thus, the attempt to use nanotechnology to improve food security and increase supply has emerged due to the severe shortcomings of conventional technologies, which have made them insufficient to cater to the continuous demand for food products. Hence, nanoparticles have been identified to play a major role in areas involving food production, protection, and shelf-life extensions. Specifically, metal-based nanoparticles have been singled out to play an important role in manufacturing materials with outstanding properties, which can help increase the shelf-life of different food materials. The physicochemical and biological properties of metal-based nanoparticles, such as the large surface area and antimicrobial properties, have made them suitable and adequately useful, not just as a regular packaging material but as a functional material upon incorporation into biopolymer matrices. These, amongst many other reasons, have led to their wide synthesis and applications, even though their methods of preparation and risk evaluation remain a topic of concern. This review, therefore, briefly explores the available synthetic methods, physicochemical properties, roles, and biological properties of metal-based nanoparticles for food packaging. Furthermore, the associated limitations, alongside quality and safety considerations, of these materials were summarily explored. Although this area of research continues to garner attention, this review showed that metal-based nanoparticles possess great potential to be a leading material for food packaging if the problem of migration and toxicity can be effectively modulated.

Chitosan-Based Antibacterial Films for Biomedical and Food Applications

Antibacterial chitosan films, versatile and eco-friendly materials, have garnered significant attention in both the food industry and medicine due to their unique properties, including biodegradability, biocompatibility, and antimicrobial activity. This review delves into the various types of chitosan films and their distinct applications. The categories of films discussed span from pure chitosan films to those enhanced with additives such as metal nanoparticles, metal oxide nanoparticles, graphene, fullerene and its derivatives, and plant extracts. Each type of film is examined in terms of its synthesis methods and unique properties, establishing a clear understanding of its potential utility. In the food industry, these films have shown promise in extending shelf life and maintaining food quality. In the medical field, they have been utilized for wound dressings, drug delivery systems, and as antibacterial coatings for medical devices. The review further suggests that the incorporation of different additives can significantly enhance the antibacterial properties of chitosan films. While the potential of antibacterial chitosan films is vast, the review underscores the need for future research focused on optimizing synthesis methods, understanding structure-property relationships, and rigorous evaluation of safety, biocompatibility, and long-term stability in real-world applications.

Mask-Assisted Deposition of Ti on Cyclic Olefin Copolymer Foil by Pulsed Laser Deposition

Cyclic olefin copolymer (COC) is a novel type of thermoplastic polymer gaining the attention of the scientific community in electronic, optoelectronic, biomedicine and packaging applications. Despite the benefits in the use of COC such as undoubted optical transparency, chemical stability, a good water-vapor barrier and biocompatibility, its original hydrophobicity restricts its wider applicability and optimization of its performances. Presently, we report on the optical and morphological properties of the films of COC covered with Ti in selected areas. The layer of Ti on COC was deposited by pulsed lased deposition processing. The Ti/COC film was characterized by UV-Vis spectroscopy indicating that its transmittance in the visible region decreased by about 20% with respect to the pristine polymer. The quality of the deposited Ti was assessed with the morphology by scanning electron (SEM) and atomic force microscopies (AFM). The modification of the wettability was observed by the sessile drop method indicating a reduction of the native hydrophilicity.

Platinum-loaded dendritic mesoporous silica as novel ethylene scavenger to extend shelf life of banana (Musa nana)

Ethylene, released from fruits and vegetables (F&V) after harvest and during storage, often accelerates the ripening or over-ripening and may be caused decay, leading to substantial economic loss. Dendritic mesoporous silica supported (DMS) platinum (Pt/DMS) catalyst as ethylene scavenger was prepared and various characterization results indicated that the as-prepared Pt/DMS with ultra-low Pt loading exhibited excellent ethylene scavenging performance, which could maintain the complete ethylene conversion (100%) over 50 h at 25 °C and even 0 °C for 100 min with superior consecutive cycles by repeating the use of Pt/DMS. The presence of Pt/DMS delayed banana softening, and browning, reduced weight loss and kept the freshness for 14 days. In conclusion, the active packaging incorporated with Pt/DMS catalysts with high ethylene scavenging efficiency is expected to be extremely beneficial to the post-harvest storage life of other fruits and vegetables that needs further related investigation.

Dysregulation along the gut microbiota-immune system axis after oral exposure to titanium dioxide nanoparticles: A possible environmental factor promoting obesity-related metabolic disorders

Food additives are one major hallmark of ultra-processed food in the Western-diet, a food habit often associated with metabolic disorders. Among these additives, the whitener and opacifying agent titanium dioxide (TiO₂) raises public health issues due to the ability of TiO₂ nanoparticles (NPs) to cross biological barriers and accumulate in different systemic organs like spleen, liver and pancreas. However before their systemic passage, the biocidal properties of TiO₂ NPs may alter the composition and activity of the gut microbiota, which play a crucial role for the development and maintenance of immune functions. Once absorbed, TiO₂ NPs may further interact with immune intestinal cells involved in gut microbiota regulation. Since obesity-related metabolic diseases such as diabetes are associated with alterations in the microbiota-immune system axis, this raises questions about the possible involvement of long-term exposure to food-grade TiO₂ in the development or worsening of these diseases. The current purpose is to review the dysregulations along the gut microbiota-immune system axis after oral TiO₂ exposure compared to those reported in obese or diabetic patients, and to highlight potential mechanisms by which foodborne TiO₂ NPs may increase the susceptibility to develop obesity-related metabolic disorders.

MRC-5 Human Lung Fibroblasts Alleviate the Genotoxic Effect of Fe-N Co-Doped Titanium Dioxide Nanoparticles through an OGG1/2-Dependent Reparatory Mechanism

The current study was focused on the potential of pure P25 TiO2 nanoparticles (NPs) and Fe(1%)-N co-doped P25 TiO2 NPs to induce cyto- and genotoxic effects in MRC-5 human pulmonary fibroblasts. The oxidative lesions of P25 NPs were reflected in the amount of 8-hydroxydeoxyguanosine accumulated in DNA and the lysosomal damage produced, but iron-doping partially suppressed these effects. However, neither P25 nor Fe(1%)-N co-doped P25 NPs had such a serious effect of inducing DNA fragmentation or activating apoptosis signaling. Moreover, oxo-guanine glycosylase 1/2, a key enzyme of the base excision repair mechanism, was overexpressed in response to the oxidative DNA deterioration induced by P25 and P25-Fe(1%)-N NPs.

Copper-based nanoparticles for biopolymer-based functional films in food packaging applications

This review summarizes the latest developments in the design, fabrication, and application of various Cu-based nanofillers to prepare biopolymer-based functional packaging films, focusing on the effects of inorganic nanoparticles on the optical, mechanical, gas barrier properties, moisture sensitivity, and functional properties of the films. In addition, the potential application of Cu-based nanoparticle-added biopolymer films for fresh food preservation and the effect of nanoparticle migration on food safety were discussed. The incorporation of Cu-based nanoparticles improved the film properties with enhanced functional performance. Cu-based nanoparticles such as copper oxide, copper sulfide, copper ions, and copper alloys affect biopolymer-based films differently. The properties of composite films containing Cu-based nanoparticles depend on the concentration of the filler, the state of dispersion, and the interaction of the nanoparticles with the biopolymer matrix in the film. The composite film filled with Cu-based nanoparticles effectively extended the shelf life by maintaining the quality of various fresh foods and securing safety. However, studies on the migration characteristics and safety of copper-based nanoparticle food packaging films are currently being conducted on plastic-based films such as polyethylene, and research on bio-based films is limited.

High performance biopolymeric packaging films containing zinc oxide nanoparticles for fresh food preservation: A review

Biodegradable food packaging films (FPFs) assembled from sustainable biopolymeric materials are of increasing interest to the food industry due to pollution and health risks resulting from the use of conventional plastic packaging. However, the functional performance of these FPFs is often poorer than that of plastic films, which limits their commercial application. This problem may be partly overcome by incorporating nano-additives like zinc oxide nanoparticles (ZNPs) into the films. The incorporation of ZNPs into FPFs can improve their functional performance. The properties of these films depends on the concentration, dispersion state, and interactions of ZNPs with the biopolymeric matrix in the films. ZNPs-loaded films and coatings are highly effective at preserving a variety of fresh foods. Studies of ZNPs migration through FPFs have shown that the zinc is mainly transported in an ionic form and the amount entering foods is below safety standards. This article reviews recent developments in the design, fabrication, and application of ZNPs-loaded FPFs based on biopolymers, focusing on the impacts of ZNPs on the optical, barrier, mechanical, water sensitivity, and antimicrobial properties of the films. The potential applications of ZNPs-loaded FPFs for fresh food preservation is also discussed.

Application of chitosan nanoparticles in quality and preservation of postharvest fruits and vegetables: A review

Chitosan is an interesting alternative material for packaging development due to its biodegradability. However, its poor mechanical properties and low permeability limit its actual applications. Chitosan nanoparticles (CHNPs) have emerged as a suitable solution to overcome these intrinsic limitations. In this review, all studies regarding the use of CHNPs to extend the shelf life and improve the quality of postharvest products are covered. The characteristics of CHNPs and their combinations with essential oils and metals, along with their effects on postharvest products, are compared and discussed throughout the manuscript. CHNPs enhanced postharvest antioxidant capacity, extended shelf life, increased nutritional quality, and promoted tolerance to chilling stress. Additionally, the CHNPs reduced the incidence of postharvest phytopathogens. In most instances, smaller CHNPs (<150 nm) conferred higher benefits than larger ones (>150 nm). This was likely a result of the greater plant tissue penetrability and surface area of the smaller CHNPs. The CHNPs were either applied after preparing an emulsion or incorporated into a film, with the latter often exhibiting greater antioxidant and antimicrobial activities. CHNPs were used to encapsulate essential oils, which could be released over time and may enhance the antioxidant and antimicrobial properties of the CHNPs. Even though most applications were performed after harvest, preharvest application had longer lasting effects.

Cellulose/inorganic nanoparticles-based nano-biocomposite for abatement of water and wastewater pollutants

Nanostructured materials offer a significant role in wastewater treatment with diminished capital and operational expense, low dose, and pollutant selectivity. Specifically, the nanocomposites of cellulose with inorganic nanoparticles (NPs) have drawn a prodigious interest because of the extraordinary cellulose properties, high specific surface area, and pollutant selectivity of NPs. Integrating inorganic NPs with cellulose biopolymers for wastewater treatment is a promising advantage for inorganic NPs, such as colloidal stability, agglomeration prevention, and easy isolation of magnetic material after use. This article presents a comprehensive overview of water treatment approaches following wastewater remediation by green and environmentally friendly cellulose/inorganic nanoparticles-based bio-nanocomposites. The functionalization of cellulose, functionalization mechanism, and engineered hybrid materials were thoroughly discussed. Moreover, we also highlighted the purification of wastewater through the composites of cellulose/inorganic nanoparticles via adsorption, photocatalytic and antibacterial approach.

Effects of the geometry of reinforcement on physical properties of sodium caseinate/TiO2 nanocomposite films for applications in food packaging

Plastic materials for food packaging are being replaced by biodegradable films based on biopolymers due to the adverse effects they have had on animal life and the environment. In this study, nanocomposite films containing 2.5 wt% sodium caseinate and 2 wt% glycerol were reinforced with 0.1 or 0.2 wt% nano TiO₂ prepared in two forms: spheres (P25) and tubes. The effects of nanoreinforcement geometry on mechanical, tensile, barrier, thermogravimetric, and optical properties, and distribution of nanoparticles were described. The interactions among film components were analyzed by Fourier transform infrared spectroscopy (FTIR). Addition of nanotubes significantly increased E' (341 wt%) and E" (395 wt%) moduli, the Young modulus E (660 wt%), the residual mass at 500°C (38 wt%), and color change (6.78) compared to control film. The compositional mapping studies showed that P25 nanoparticles were homogeneously distributed between the surfaces of the film while nanotubes were found on the bottom surface. The changes in position of the FTIR spectra signals as compared to pure protein signals indicated strong matrix/reinforcement interactions. In addition, the changes in intensity in 1100, 1033, and 1638 cm^-1 FTIR signals suggested formation of a protein/Tween 20 ester. The geometry of reinforcement was highly relevant regarding physical properties, showing nanotubes as being very successful for enhancing tensile properties.

Multifunctional nanocomposite based on polyvinyl alcohol, cellulose nanocrystals, titanium dioxide, and apple peel extract for food packaging

Although polyvinyl alcohol (PVA) is a potential biodegradable food packaging material, it has several critical limitations: low mechanical strength, poor ultraviolet (UV) and water vapor barrier properties, and lack of antioxidant and antimicrobial properties. Previous studies have used cellulose nanocrystals (CNCs) to improve the mechanical and water vapor barrier properties of the PVA matrix. In this study, a multifunctional nanocomposite for food packaging applications was developed by incorporating titanium dioxide (TiO₂) and apple peel extract (APE) into a PVA/CNC matrix. The combination of TiO₂ and APE in the nanocomposites not only enhanced multifunctionality but also improved mechanical and barrier properties. The mechanical strength and water vapor barrier properties of PVA/CNC/TiO₂/APE (5 wt% TiO₂ and 20 wt% APE in the PVA/CNC matrix containing 5 wt% of CNCs) increased by 49.9 % and 36.6 % compared to PVA. Furthermore, PVA/CNC/TiO₂/APE exhibited an excellent UV barrier (UV-protection factor of 1012.73) and high antioxidant and antimicrobial properties. In food packaging tests with fresh cherry tomatoes and potatoes, PVA/CNC/TiO₂/APE effectively protected samples from external influences and prolonged their self-life, demonstrating the potential use of this nanocomposite as a biodegradable and multifunctional food packaging material.

Effect of TiO2 Nanoparticles and Extrusion Process on the Physicochemical Properties of Biodegradable and Active Cassava Starch Nanocomposites

Biodegradable polymers have been strongly recognized as an alternative to replace traditional petrochemical plastics, which have become a global problem due to their long persistence in the environment. In this work, the effect of the addition of titanium dioxide nanoparticles (TiO₂NP) on the morphology, physicochemical properties and biodegradation under industrial composting conditions of cassava starch-based nanocomposites obtained by extrusion at different screw speeds (80 and 120 rpm) were investigated. Films performed at 120 rpm (S₁₂₀ and S₁₂₀-TiO₂NP) showed completely processed starch and homogeneously distributed nanoparticles, leading to much more flexible nanocomposites than those obtained at 80 rpm. The incorporation of TiO₂NP led to an increase in storage modulus of all films and, in the case of S₁₂₀-TiO₂NP, to higher strain at break values. From the Kohlrausch-Williams-Watts theoretical model (KWW), an increase in the relaxation time of the nanocomposites was observed due to a decrease in the number of polymer chains involved in the relaxation process. Additionally, S₁₂₀-TiO₂NP showed effective protection against UV light, greater hydrophobicity and faster biodegradation in compost, resulting in a promising material for food packaging applications.

The interfacial behaviors of different arsenic species on polyethylene mulching film microplastics: Roles of the plastic additives

Plastic additives widely existed in plastic mulching films, but their roles in microplastics (MPs) derived from these plastics as vectors of pollutants were not clear. This work clarified the role of plastic additives on the sorption-desorption behaviors of four arsenic species (arsenite (As(Ⅲ)), arsenate (As(Ⅴ)), roxarsone (ROX), and p-arsanilic acid (p-ASA)) on/from virgin polyethylene (V-PE), white PE mulching film (W-PE, with Si-containing additives), and black PE mulching film (B-PE, with CaCO₃ and TiO₂ additives) MPs. The maximum sorption amounts of arsenic species on V-PE (3.33-20.10 mg/kg) and W-PE MPs (4.78-21.93 mg/kg) had no significant difference, while those on B-PE (43.02-252.19 mg/kg) facilitated by its additives were up to one order of magnitude greater than V-PE or W-PE (p < 0.05). Desorption hysteresis index (HI) indicated the irreversible arsenic sorption on three PE MPs, especially for B-PE containing additives that can co-precipitate and complex with arsenicals. The effects of pH, humic substances, and coexisting anions on arsenic sorption by B-PE were more obvious than that by V-PE or W-PE MPs, attributing to electrostatic interaction enhanced by CaCO₃ and TiO₂ additives. This work provides theoretical basis for migration of arsenic species on MPs containing plastic additives and their potential environmental risk assessment.