Preparation and Characterization of Whey Protein Film Incorporated with TiO2Nanoparticles

Enhancing storage and gastroprotective viability of Lactiplantibacillus plantarum encapsulated by sodium caseinate-inulin-soy protein isolates composites carried within carboxymethyl cellulose hydrogel

Probiotics are subjected to various edible coatings, especially proteins and polysaccharides, which serve as the predominant wall materials, with ultrasound, a sustainable green technology. Herein, sodium caseinate, inulin, and soy protein isolate composites were produced using multi-frequency ultrasound and utilized to encapsulateLactiplantibacillus plantarumto enhance its storage, thermal, and gastrointestinal viability. The physicochemical analyses revealed that the composites with 5 % soy protein isolate treated with ultrasound at 50 kHz exhibited enough repulsion forces to maintain stability, pH resistance, and the ability to encapsulate larger particles and possessed the highest encapsulation efficiency (95.95 %). The structural analyses showed changes in the composite structure at CC, CH, CO, and amino acid residual levels. Rheology, texture, and water-holding capacity demonstrated the production of soft hydrogels with mild chewing and gummy properties, carried the microcapsules without coagulation or sedimentation. Moreover, the viability attributes ofL. plantarumevinced superior encapsulation, protecting them for at least eight weeks and against heat (63 °C), reactive oxidative species (H2O2), and GI conditions.

A Soy Protein-Based Film Based on Chemical Treatment and Microcrystalline Cellulose Reinforcement Obtained from Corn Husk Byproducts

Developing an environmentally friendly soy protein-based film that offers excellent performance has garnered considerable interest while also posing a significant challenge. Herein, we propose the strategy of covalent and noncovalent cross-linking to improve the mechanical properties of the films. First, chemical denaturation was carried out under the combined action of sodium sulfite, sodium dodecyl sulfate, sodium hydroxide, and urea to reshape the structure of the protein to improve the solubility of protein and release active groups. Then, microcrystalline cellulose (MCC) derived from low-cost agro-industrial byproducts (corn husk) was employed to balance the covalent cross-linking reaction between proteins and the noncovalent reaction between MCC and protein. The results indicate that the structure and properties of the soy protein-based films were modified and improved through chemical treatment in conjunction with biomass enhancement. It is concluded that the addition of 1% MCC improves the tensile strength, elastic modulus, water solubility, and water vapor permeability of "MCC-1%" by 64.7, 75.9, 22.7, and 12.9%, respectively. Additionally, the resulting film of "MCC-1%" exhibits better resistance to thermal degradation and improved thermo-stability. However, the elongation at break decreased by increasing the addition of MCC. Thus, this work may provide a simple and affordable approach to preparing a high-performing soy protein-based film.

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.

Characterization of a Graphene Oxide-Reinforced Whey Hydrogel as an Eco-Friendly Absorbent for Food Packaging

This study presents a structural analysis of a whey and gelatin-based hydrogel reinforced with graphene oxide (GO) by ultraviolet and visible (UV-VIS) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results revealed barrier properties in the UV range for the reference sample (containing no graphene oxide) and the samples with minimal GO content of 0.66×10−3% and 3.33×10−3%, respectively, in the UV-VIS and near-IR range; for the samples with higher GO content, this was 6.67×10−3% and 33.33×10−3% as an effect of the introduction of GO into the hydrogel composite. The changes in the position of diffraction angles 2θ from the X-ray diffraction patterns of GO-reinforced hydrogels indicated a decrease in the distances between the turns of the protein helix structure due to the GO cross-linking effect. Transmission electron spectroscopy (TEM) was used for GO, whilst scanning electron microscopy (SEM) was used for the composite characterization. A novel technique for investigating the swelling rate was presented by performing electrical conductivity measurements, the results of which led to the identification of a potential hydrogel with sensor properties.

A. Ali G. Inhibitory effect of Titanium dioxide (Tio2) nanoparticles and their synergistic activity with antibiotics in some types of bacteria

Titanium dioxide nanoparticles (TiO2 NPs) were studied as antibacterial agents at different concentrations against clinical and environmental bacterial isolates without UV or photocatalytic activation. Five TiO2 NPs concentrations (20µg/ml,50µg/ml, 100µg/ml,500µg/ml and 1000µg/ml) were studied against 15 bacterial species:10 clinical isolates and 5 environmental isolates) compared with antibiotics Amikacin(AK)and Levloxacin(LEV).Only500µg/ml concentration of TiO2 NPs was active against 7 bacterial isolates (3 clinical and 4 environmental), and 1000µg/ml concentration of TiO2 NPs was effective against 9 isolates (6 clinical and 3 environmental ). These concentrations were mixed with the antibiotics Levloxacin LEV and Amikacin AK to investigate the possibility of synergistic activity against studied bacteria. Bacterial isolate's response or sensitivity to the antibiotic and TiO2 NPs mixture was varied; AK plus 500µg/ml TiO2 NPs concentration showed increased inhibitory activity against 7 isolates (3 clinical, 4 environmental) and 1000µg/ml TiO2 NPs mixed with AK showed increased inhibition activity against one environmental bacterial isolates, where Ak mixed with 500 and Ak plus 1000 µg/ml showed the same effect as the antibiotic alone or less.LEV antibiotic shows no difference in the effect on all 9 bacteria (7 clinical and 2 environmental), while LEV mixed with 500 µg/ml have increased inhibition zones on 4 bacteria (2 clinical, 2 environmental) , and LEV mixed with 1000µg/ml have higher effect than the antibiotic alone on three isolates (2 clinical,1 environmental). Keywords: antibiotic; titanium nanoparticles dioxide; antibacterial.

Photo-degradable and recyclable starch/Fe3O4/TiO2 nanocomposites: feasibility of an approach to reduce the recycling labor cost in plastic waste management

In this research, a biodegradable starch/Fe₃O₄/TiO₂ bio-nanocomposites (SFT) were produced using different nano Fe₃O₄/TiO₂ (FT) (3, 5, and 10 (wt% dry based)) contents. Mechanical properties, visual properties, moisture-sensitive parameters, magnetic properties, and physical properties of the film specimens were investigated. Photodegradability of film specimens was also evaluated under UV-A irradiation. The FT content increased the hydrophobicity of the film specimens. Tensile strength (TS) of SFT films was increased by increasing FT up to 3%. Elongation at break (EB) and tensile energy to break (TEB) were decreased by adding FT content up to 3% simultaneously. The film specimens' water vapor permeability (WVP) was decreased with increasing FT content. The intrinsic viscosity of SFT was decreased by increasing FT content. It confirms the enhancement of photodegradability of the specimens by increasing FT content. It seems the compatibility of FT with biopolymer has had great effects on these properties. Use of FT-based nanocomposites is an appropriate approach to developing magnetic-recyclable and photodegradable packaging materials.

Developing Self-Assembled Starch Nanoparticles in Starch Nanocomposite Films

Starch nanoparticles (SNPs) are synthesized by different precipitation techniques using corn starch, and SNP films are prepared by the evaporation casting method. The morphological study is investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The distribution and sizes of precipitated SNPs after synthesizing are discovered by these methods as well. The crystallinity of the SNPs is studied by the X-ray diffractometry (XRD) method that demonstrates reduction compared to neat starch granules, and it is changed from A-style to V_H-style after precipitation. The chemical bonding of different SNPs after the nanoprecipitation is analyzed by Fourier transform infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) demonstrates the decomposition of starch nanoparticles and the starch matrix that is related to the depolymerization of carbon chains in the range of 260 to 350 °C. The mechanical properties of the SNP films versus the temperature changing are discovered by dynamic mechanical analysis (DMA). The water contact angles of SNP films are measured using a goniometer, and the results showed the hydrophobic surfaces of the prepared films. Our study indicates that SNPs have a promising impact on the properties of corn starch films, which would be useful in biodegradable packaging material.

Preparation and Physiochemical Characterization of Bitter Orange Oil Loaded Sodium Alginate and Casein Based Edible Films

Biopolymers-based composite edible films are gaining interest in the food packaging industry due to their sustainable nature and diverse biological activities. In the current study, we used sodium alginate (SA) and casein (CA) for the fabrication of composite film using the casting method. We also added orange oil to the edible film and assessed its impact on the biological, chemical, physical, and barrier properties of the films. The fabricated films were analyzed using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). It was observed that CA–SA films loaded with 1.5% OEO had better visual attributes, and a further increase in oil concentration was not found to be as favorable. Mechanical assessment of the films revealed that CA–SA-OEO (1.5%) film showed lower puncture deformation and higher puncture force values. XRD data showed that all samples exhibited peaks at similar positions (21° of 2θ) with different intensities. In FTIR analysis, characteristic peaks of the film components (sodium alginate, casein, and orange oil) were reported at corresponding positions. The thermal stability of films was enhanced after the addition of the OEO (1.5%), however, a greater increase in OEO caused a decrease in the thermal stability, observed during TGA analysis. Moreover, the surface of the blank CA–SA film (FL1) was found to be rough (with cracks) compared to CA–SA films (FL2) containing 1.5% OEO. Additionally, FL2 was found to be relatively better than the other samples in terms of swelling degree (SD), thickness, water solubility (WS), oxygen permeability (OP), water vapor permeability (WVP), moisture content (MC), and transparency (T).

Enhancement of photocatalytic and biological activities of chitosan/activated carbon incorporated with TiO2 nanoparticles

Novel and sustainable chitosan (CS)/activated charcoal (AC) composites were prepared by cross-linking with epichlorohydrin (ECH) to form a porous structure. Different titanium dioxide nanoparticle (TiO₂ NPs) concentrations (0, 0.2, 0.4, and 0.8% w/w) were added to enhance the photocatalytic, antibacterial, larvicidal, and pupicidal activities' efficiency toward Rose Bengal (RB) dye and the Culex pipiens. The composites were characterized by FT-IR, XRD, XPS, BET and SEM. The SEM images revealed the porous structure of CS/AC and TiO₂ nanoparticles were uniformly distributed in the CS/AC matrix. The degradation of RB dye was used to test the photocatalytic behavior of the composites. Supporting TiO₂ on a CS/AC matrix resulted in a significant increase in photocatalytic performance. The antibacterial activities supported by CS/AC/TiO₂ NPs were evaluated by bacterial growth inhibition against B. subtilis, S. aureus, E. coli, and P. aeruginosa. The results showed that CS/AC/TiO₂ NPs composite has an inhibitory effect and therefore considered antibacterial agents. CS/AC/0.4%TiO₂ NPs showed maximum efficacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, and 92.20 ± 2.64 for the first, second, and third larval instars and 66.00 ± 2.39 for pupal mortality, while the repellent activity reported high protection at 82.95 ± 2.99 with 3.24 mg/cm² dose compared to control DEET.

ANTIMICROBIAL BIODEGRADABLE PACKAGING FOR SLICED BAKERY

In the modern minds of the advanced ecology and safety of food products control, it is relevant the development of antimicrobial biodegradable packaging. The article presents the results of the antagonistic action of nanodispersed titanium dioxide powder (TiO2) at the warehouse of biodegradable packaging for bakery products on the living of microorganisms (Escherichia сoli, Bacillus subtilis, Candida albicans, Aspergillus niger). It is known there are developments on the use of antimicrobial substances of both organic and inorganic origin, the microbiological action of the substances used have an effect on pathogenic, opportunistic, fungi, gram-negative and gram-positive bacteria. We found that the introduction of 1% TiO2 r into the molding solution allows to give the package antibacterial properties, as it inhibits the development of Escherichia coli and Bacillus subtilis, as there is a delay in the growth of their colonies compared to the sample without packaging with TiO2. According to the results of provocative testing, biodegradable packaging with a content of 1% TiO2 has an inhibitory effect on Bacillus subtilis. In addition to antimicrobial properties, the package under study must also have barrier properties, so the vapor permeability of the presented package was determined. The study results show that the addition of 1% TiO2 slightly reduces the vapor permeability, but the increase in the concentration 2–5% of TiO2 causes an increase in vapor permeability from 4.7 to 5.2 mg / (m∙h∙kPa). The vapor permeability of the presented biodegradable antimicrobial packaging is due to the presence of pores, the number and size of which were determined experimentally. Thus, nanodispersed TiO2 in the amount of 1% in the molding solution of the biodegradable coating is an effective antimicrobial component for antimicrobial coatings, which does not impair their barrier properties.

Nano-Enable Materials Promoting Sustainability and Resilience in Modern Agriculture

Intensive conventional agriculture and climate change have induced severe ecological damages and threatened global food security, claiming a reorientation of agricultural management and public policies towards a more sustainable development model. In this context, nanomaterials promise to support this transition by promoting mitigation, enhancing productivity, and reducing contamination. This review gathers recent research innovations on smart nanoformulations and delivery systems improving crop protection and plant nutrition, nanoremediation strategies for contaminated soils, nanosensors for plant health and food quality and safety monitoring, and nanomaterials as smart food-packaging. It also highlights the impact of engineered nanomaterials on soil microbial communities, and potential environmental risks, along with future research directions. Although large-scale production and in-field testing of nano-agrochemicals are still ongoing, the collected information indicates improvements in uptake, use efficiency, targeted delivery of the active ingredients, and reduction of leaching and pollution. Nanoremediation seems to have a low negative impact on microbial communities while promoting biodiversity. Nanosensors enable high-resolution crop monitoring and sustainable management of the resources, while nano-packaging confers catalytic, antimicrobial, and barrier properties, preserving food safety and preventing food waste. Though, the application of nanomaterials to the agri-food sector requires a specific risk assessment supporting proper regulations and public acceptance.

Self-assembly in biobased nanocomposites for multifunctionality and improved performance

Concerns of petroleum dependence and environmental pollution prompt an urgent need for new sustainable approaches in developing polymeric products. Biobased polymers provide a potential solution, and biobased nanocomposites further enhance the performance and functionality of biobased polymers. Here we summarize the unique challenges and review recent progress in this field with an emphasis on self-assembly of inorganic nanoparticles. The conventional wisdom is to fully disperse nanoparticles in the polymer matrix to optimize the performance. However, self-assembly of the nanoparticles into clusters, networks, and layered structures provides an opportunity to address performance challenges and create new functionality in biobased polymers. We introduce basic assembly principles through both blending and in situ synthesis, and identify key technologies that benefit from the nanoparticle assembly in the polymer matrix. The fundamental forces and biobased polymer conformations are discussed in detail to correlate the nanoscale interactions and morphology with the macroscale properties. Different types of nanoparticles, their assembly structures and corresponding applications are surveyed. Through this review we hope to inspire the community to consider utilizing self-assembly to elevate functionality and performance of biobased materials. Development in this area sets the foundation for a new era of designing sustainable polymers in many applications including packaging, construction chemicals, adhesives, foams, coatings, personal care products, and advanced manufacturing.

Antimicrobial properties of nanoparticles in the context of advantages and potential risks of their use

The popularity of nanotechnology results from the possibility of obtaining materials that have better chemical, electrical, thermal, mechanical, or optical properties. Nano-sized materials are characterized by an increased surface area, which improves their chemical reactivity and mobility. Due to their enhanced reactivity and appropriately small size, some nanoparticles are used as antimicrobial and antifungal agents. Nanoparticles exhibit antimicrobial potential through multifaceted mechanisms. The adhesion of nanoparticles to microbial cells, and reactive oxygen species, and their penetration inside the cells, have been recognized as the most prominent modes of antimicrobial action. This review presents the mechanism of action of nanometals and oxide nanoparticles used as antimicrobials and the mechanisms of bacterial resistance to the toxic effects of nanoparticles. The article presents methods of forming microorganism resistance to the toxic effects of nanoparticles and the negative impact of nanoparticles on human health.

Proteins from Agri-Food Industrial Biowastes or Co-Products and Their Applications as Green Materials

A great amount of biowastes, comprising byproducts and biomass wastes, is originated yearly from the agri-food industry. These biowastes are commonly rich in proteins and polysaccharides and are mainly discarded or used for animal feeding. As regulations aim to shift from a fossil-based to a bio-based circular economy model, biowastes are also being employed for producing bio-based materials. This may involve their use in high-value applications and therefore a remarkable revalorization of those resources. The present review summarizes the main sources of protein from biowastes and co-products of the agri-food industry (i.e., wheat gluten, potato, zein, soy, rapeseed, sunflower, protein, casein, whey, blood, gelatin, collagen, keratin, and algae protein concentrates), assessing the bioplastic application (i.e., food packaging and coating, controlled release of active agents, absorbent and superabsorbent materials, agriculture, and scaffolds) for which they have been more extensively produced. The most common wet and dry processes to produce protein-based materials are also described (i.e., compression molding, injection molding, extrusion, 3D-printing, casting, and electrospinning), as well as the main characterization techniques (i.e., mechanical and rheological properties, tensile strength tests, rheological tests, thermal characterization, and optical properties). In this sense, the strategy of producing materials from biowastes to be used in agricultural applications, which converge with the zero-waste approach, seems to be remarkably attractive from a sustainability prospect (including environmental, economic, and social angles). This approach allows envisioning a reduction of some of the impacts along the product life cycle, contributing to tackling the transition toward a circular economy.

Employing Nanosilver, Nanocopper, and Nanoclays in Food Packaging Production: A Systematic Review

Over the past decade, there has been an increasing demand for “ready-to-cook” and “ready-to-eat” foods, encouraging food producers, food suppliers, and food scientists to package foods with minimal processing and loss of nutrients during food processing. Following the increasing trend in the customer’s demands for minimally processed foodstuffs, this underscores the importance of promising interests toward industrial applications of novel and practical approaches in food. Along with substantial progress in the emergence of “nanoscience”, which has turned into the call of the century, the efficacy of conventional packaging has faded away. Accordingly, there is a wide range of new types of packaging, including electronic packaging machines, flexible packaging, sterile packaging, metal containers, aluminum foil, and flexographic printing. Hence, it has been demonstrated that these novel approaches can economically improve food safety and quality, decrease the microbial load of foodborne pathogens, and reduce food spoilage. This review study provides a comprehensive overview of the most common chemical or natural nanocomposites used in food packaging that can extend food shelf life, safety and quality. Finally, we discuss applying materials in the production of active and intelligent food packaging nanocomposite, synthesis of nanomaterial, and their effects on human health.

A review on TiO2-based photocatalytic systems applied in fruit postharvest: Set-ups and perspectives

Titanium dioxide (TiO₂) is a photocatalytic material used to degrade ethylene, and it has been studied as an alternative postharvest technology. Although several studies have indicated the effective action of TiO₂ photocatalysis for delaying the fruit ripening, photocatalytic systems need to be well-designed for this application. Fruit is susceptible to environmental conditions like temperature, relative humidity, atmosphere composition and exposure to UV-light. This fragility associated with its variable ethylene production rate over its maturation stage limits the photocatalysis parameters optimization. Thus, this review aims to detail the reaction mechanisms, set-up, advantages, and limitations of TiO₂ photocatalytic systems based on polymers-TiO₂ nanocomposites and reactors containing TiO₂ immobilized into inorganic supports designed for fruit applications. It is expected that this review can elucidate the fundamental aspects that should be considered for the use of these systems.

Migration of Silver and Copper Nanoparticles from Food Coating

Packaging containing nanoparticles (NPs) can increase the shelf life of products, but the presence of NPs may hazards human life. In this regard, there are reports regarding the side effect and cytotoxicity of nanoparticles. The main aim of this research was to study the migration of silver and copper nanoparticles from the packaging to the food matrix as well as the assessment techniques. The diffusion and migration of nanoparticles can be analyzed by analytical techniques including atomic absorption, inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission, and inductively coupled plasma optical emission spectroscopy, as well as X-ray diffraction, spectroscopy, migration, and titration. Inductively coupled plasma-based techniques demonstrated the best results. Reports indicated that studies on the migration of Ag/Cu nanoparticles do not agree with each other, but almost all studies agree that the migration of these nanoparticles is higher in acidic environments. There are widespread ambiguities about the mechanism of nanoparticle toxicity, so understanding these nanoparticles and their toxic effects are essential. Nanomaterials that enter the body in a variety of ways can be distributed throughout the body and damage human cells by altering mitochondrial function, producing reactive oxygen, and increasing membrane permeability, leading to toxic effects and chronic disease. Therefore, more research needs to be done on the development of food packaging coatings with consideration given to the main parameters affecting nanoparticles migration.

Ethylene scavenging properties from hydroxypropyl methylcellulose-TiO2 and gelatin-TiO2 nanocomposites on polyethylene supports for fruit application

Several technologies have been proposed to preserve fruits and to avoid postharvest losses. The degradation of ethylene produced by the fruits using TiO₂ photocatalysis has shown to be a good option to delay the ripening of fruits. This paper proposed a new application of biopolymers-TiO₂ nanocomposites developed to extend the shelf-life of fruits. Photocatalytic coatings were applied on the expanded polyethylene foam nets to degrade ethylene. Gelatin and hydroxypropyl methylcellulose (HMPC) were tested as hydrophobic and hydrophilic matrices for the TiO₂ incorporation. First, nanocomposite films prepared by casting were evaluated with regards to their photocatalytic properties. Both matrices, which were loaded with 1 wt% TiO₂, degraded 40% of the ethylene injected in a batch reactor. By Langmuir-Hinshelwood model, ethylene degradation using gelatin-TiO₂ films (k_app = 0.186 ± 0.021 min^-1) was faster than the HPMC-TiO₂ films (k_app = 0.034 ± 0.003 min^-1). Then, gelatin-TiO₂ dispersion was applied as a coating on the foam nets by dip coating. The gelatin-TiO₂ bilayer exhibited higher concentration of ethylene degraded per photocatalytic area and photocatalyst mass unit (13.297 ± 0.178 ppmv m² [Formula: see text] ) than its film form (18.212 ± 1.157 ppmv m² [Formula: see text] ), which makes gelatin-TiO₂/foam nets a promising composite design for fruit postharvest application.

Preparation of polylactic acid/TiO2/GO nano-fibrous films and their preservation effect on green peppers

Polylactic acid (PLA)/nano-TiO₂(TiO₂ NPs)/Graphene oxide (GO) nano-fibrous films were prepared by ultrasonic assisted electrostatic spinning technology, and the effects of TiO₂ NPs:GO mass ratio and ultrasonic power on film morphology and mechanical, thermal, barrier and antibacterial properties were investigated. The addition of TiO₂ NPs and GO can significantly increase the tensile strength and elongation at the break of PLA nano-fibrous films, and improve the water barrier properties of the nano-fibrous films. The antibacterial experiment showed that the inhibition rates of the nano-fibrous films against Escherichia coli and Staphylococcus aureus after 24 h exposure to UV irradiation reached 94.4 ± 1.8% and 92.6 ± 1.7% At the same time, the fresh-keeping packaging experiment of green peppers at room temperature, through the determination of hardness, soluble solids, chlorophyll content to determine the degree of decay of green pepper, it showed that PLA/TiO₂ NPs/GO nano-fibrous films can better maintain the sensory quality of green peppers, delay the rate of spoilage of green peppers, and prolong the preservation period of green peppers.

A review on the biological effects of nanomaterials on silkworm (Bombyx mori)

The production of high-quality silkworm silk is of importance in sericulture in addition to the production of biomass, silk proteins, and animal feed. The distinctive properties of nanomaterials have the potential to improve the development of various sectors including medicine, cosmetics, and agriculture. The application of nanotechnology in sericulture not only improves the survival rate of the silkworm, promotes the growth and development of silkworm, but also improves the quality of silk fiber. Despite the positive contributions of nanomaterials, there are a few concerns regarding the safety of their application to the environment, in humans, and in experimental models. Some studies have shown that some nanomaterials exhibit toxicity to tissues and organs of the silkworm, while other nanomaterials exhibit therapeutic properties. This review summarizes some reports on the biological effects of nanomaterials on silkworm and how the application of nanomaterials improves sericulture.

Smart edible films based on mucilage of lallemantia iberica seed incorporated with curcumin for freshness monitoring

The objective of the present work was first to develop a smart packaging system based on Lallemantia iberica seed gum (LISG)/curcumin and, subsequently, investigate its physicochemical characteristics and biological activity. Finally, the response of LISG/curcumin films against pH change and the spoilage of shrimp were tested. The barrier properties and mechanical performance of the films improved as the curcumin concentration increased. FT-IR analysis revealed the formation of physical interaction between LISG and curcumin. LISG/curcumin films showed a continuous and steady release of curcumin. The incorporation of curcumin into LISG matrix imparts antioxidant and antibacterial/mold activity to the films. A strong positive correlation was observed between total volatile base nitrogen (TVBN) content of shrimp and a* (redness) during storage time (Pearson correlation = 0.975). Eventually, LISG/curcumin film could be a promising smart packaging system capable of detecting food spoilage.

Protein–TiO2: A Functional Hybrid Composite with Diversified Applications

Functionalization of protein-based materials by incorporation of organic and inorganic compounds has emerged as an active research area due to their improved properties and diversified applications. The present review provides an overview of the functionalization of protein-based materials by incorporating TiO2 nanoparticles. Their effects on technological (mechanical, thermal, adsorptive, gas-barrier, and water-related) and functional (antimicrobial, photodegradation, ultraviolet (UV)-protective, wound-healing, and biocompatibility) properties are also discussed. In general, protein–TiO2 hybrid materials are biodegradable and exhibit improved tensile strength, elasticity, thermal stability, oxygen and water resistance in a TiO2 concentration-dependent response. Nonetheless, they showed enhanced antimicrobial and UV-protective effects with good biocompatibility on different cell lines. The main applications of protein–TiO2 are focused on the development of eco-friendly and active packaging materials, biomedical (tissue engineering, bone regeneration, biosensors, implantable human motion devices, and wound-healing membranes), food preservation (meat, fruits, and fish oil), pharmaceutical (empty capsule shell), environmental remediation (removal and degradation of diverse water pollutants), anti-corrosion, and textiles. According to the evidence, protein–TiO2 hybrid composites exhibited potential applications; however, standardized protocols for their preparation are needed for industrial-scale implementation.

Eco-friendly UV protective bionanocomposite based on Salep-mucilage/flower-like ZnO nanostructures to control photo-oxidation of kilka fish oil

The carbohydrate source has shown great potential for preparing edible film structures, particularly as bionanocomposite edible films. In the present study, highly effective eco-friendly UV protective bionanocomposite based on Salep-mucilage (SaM)/ZnO flower-like (ZnOF) nanostructures were developed and characterized. To investigate microstructure and structure properties of SaM/ZnO_F bionanocomposite, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques, Fourier transformed infrared (FT-IR) and X-ray diffraction (XRD) were utilized. Our results showed that the increasing ZnO_F content decreased transparency (~80%) of the bionanocomposites. The hunter color values observations confirmed the films' UV-Vis spectrum and their UV-protective properties. Additionally, SaM/ZnO_F bionanocomposite were examined for their efficacy to decrease photo-oxidation in kilka fish oil under fluorescent light during 12 days of storage. The outcomes of our investigation confirm that SaM/ZnO_F bionanocomposite with performance as the adequate light barrier to delay photo-oxidation of kilka fish oil during extended storage.

Improving gelatin-based emulsion films with cold plasma using different gases

In this research, the effects of cold plasma treatment on the properties of gelatin-based emulsion films (GEFs) using different gases were investigated. The gases used include O2, N2, air, Ar, and ethanol-argon (EtOH-Ar). Surface hydrophobicity, morphology, water vapor permeability (WVP), and mechanical, thermal, and antifungal properties after plasma application on the film were analyzed. The results revealed that surface hydrophilicity significantly increased after cold plasma, while the contact angle significantly decreased (p < .05). Furthermore, atomic force microscopy results showed that the argon gas plasma significantly increased roughness of the GEFs surface. Besides, plasma did not decrease WVP. Different gases had no significant effect on the mechanical properties of the GEFs (p > .05). Oxygen permeability after plasma application was significantly different from the control sample; consequently, the permeability after plasma application decreased and the lowest level 55.7 (cm3μm m-2 day-1 Pa-1) was seen for oxygen gas. Plasma treatment caused etching effects and lessened the surface moisture of the polymer film. Antimicrobial activity was observed in the cold plasma-treated samples, especially under air and nitrogen atmosphere. Cold plasma treatment is an effective method for surface modification, expanding the application of emulsion films in the packing industry with improved performance properties.

Use of Titanium Dioxide (TiO2) Nanoparticles as Reinforcement Agent of Polysaccharide-Based Materials

In recent years, a strong interest has emerged in polysaccharide-hybrid composites and their potential applications, which have interesting functional and technological properties. This review summarizes and discusses the reported advantages and limitations of the functionalization of conventional and nonconventional polysaccharides by adding TiO2 nanoparticles as a reinforcement agent. Their effects on the mechanical, thermal, and UV-barrier properties as well as their water-resistance are discussed. In general, the polysaccharide–TiO2 hybrid materials showed improved physicochemical properties in a TiO2 content-dependent response. It showed antimicrobial activity against bacteria (gram-negative and gram-positive), yeasts, and molds with enhanced UV-protective effects for food and non-food packaging purposes. The reported applications of functionalized polysaccharide–TiO2 composites include photocatalysts (dye removal from aqueous media and water purification), biomedical (wound-healing material, drug delivery systems, biosensor, and tissue engineering), food preservation (fruits and meat), cosmetics (sunscreen and bleaching tooth treatment), textile (cotton fabric self-cleaning), and dye-sensitized solar cells. Furthermore, the polysaccharide–TiO2 showed high biocompatibility without adverse effects on different cell lines, indicating that their use in food, pharmaceutical, and biomedical applications is safe. However, it is necessary to evaluate the structural changes promoted by the storage conditions (time and temperature) on the physicochemical properties of polysaccharide–TiO2 hybrid composites to guarantee their stability during a determined time.

Nanocomposite films consisting of functional nanoparticles (TiO2 and ZnO) embedded in 4A-Zeolite and mixed polymer matrices (gelatin and polyvinyl alcohol)

In this study, nanocomposite films with enhanced functional properties were prepared by loading titanium dioxide (TiO₂) and/or zinc oxide (ZnO) nanoparticles within 4A zeolite (4AZ) particles, and then incorporating these nanocomposites into a poly (vinyl alcohol) (PVA) and gelatin matrix. The composition and morphology of the films were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The thermal behavior of the films was established using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). SEM showed the nanoparticles were dispersed throughout the films when used at these levels. FTIR indicated that the inorganic nanoparticles interacted with the PVA/gelatin polymer network through hydrogen bonding. XRD confirmed that the nanoparticles were in a crystalline state within the films. DSC and TGA showed that introduction of the nanoparticles modified the nanocomposite's thermal behavior. Nanoparticle addition had a number of effects: (i) it decreased film transparency from 78.7% to 69.4% 72.0% and 69.7%; (ii) it decreased film water vapor permeability (WVP) from 8.20 × 10^-9 to 5.13 × 10^-9, 5.71 × 10^-9 and 5.24 × 10^-9 g/Pa.h.m; (iii) it reduced film oxygen permeability from 4.57 to 3.29, 3.10 and 3.00 mEq/g; and (i) it increased film tensile strength (TS) from 14.6 to 22.0, 20.3 and 18.0 MPa, for PVA/gelatin films containing 0%, 1.5% ZnO, 1.5% TiO₂ and 1% (ZnO + TiO₂) nanoparticles, respectively (with the nanoparticles being trapped within 4AZ). Moreover, active nanocomposite films exhibited significant antimicrobial effects especially against gram-negative bacteria. Overall, our results show that nanoparticle-loaded PVA/gelatin nanocomposites may be useful as active biodegradable nanocomposite films for application in the packaging industry and that their properties can be modulated by controlling the nature and level of nanoparticles incorporated.

A Blinking Mesoporous TiO2-x Composed of Nanosized Anatase with Unusually Long-Lived Trapped Charge Carriers

A mesoporous TiO_2-x material comprised of small, crystalline, vacancy-rich anatase nanoparticles (NPs) shows unique optical, thermal, and electronic properties. It is synthesized using polymer-derived mesoporous carbon (PDMC) as a template. The PDMC pores serve as physical barriers during the condensation and pyrolysis of a titania precursor, preventing the titania NPs from growing beyond 10 nm in size. Unlike most titania nanomaterials, during pyrolysis the NPs undergo no transition from the anatase to rutile phase and they become catalytically active reduced TiO_2-x . When exposed to a slow electron beam, the NPs exhibit a charge/discharge behavior, lighting up and fading away for an average period of 15 s for an extended period of time. The NPs also show a 50 nm red-shift in their UV/Vis absorption and long-lived charge carriers (electrons and holes) at room temperature in the dark, even long after UV irradiation. The NPs as photocatalysts show a good activity for CO₂ reduction.

Bio-Based Packaging: Materials, Modifications, Industrial Applications and Sustainability

Environmental impacts and consumer concerns have necessitated the study of bio-based materials as alternatives to petrochemicals for packaging applications. The purpose of this review is to summarize synthetic and non-synthetic materials feasible for packaging and textile applications, routes of upscaling, (industrial) applications, evaluation of sustainability, and end-of-life options. The outlined bio-based materials include polylactic acid, polyethylene furanoate, polybutylene succinate, and non-synthetically produced polymers such as polyhydrodyalkanoate, cellulose, starch, proteins, lipids, and waxes. Further emphasis is placed on modification techniques (coating and surface modification), biocomposites, multilayers, and additives used to adjust properties especially for barriers to gas and moisture and to tune their biodegradability. Overall, this review provides a holistic view of bio-based packaging material including processing, and an evaluation of the sustainability of and options for recycling. Thus, this review contributes to increasing the knowledge of available sustainable bio-based packaging material and enhancing the transfer of scientific results into applications.

Preparation and characterization of TiO2-Ag loaded fish gelatin-chitosan antibacterial composite film for food packaging

In this study, fish gelatin and chitosan were used as the film-forming substrate, and different concentrations of TiO₂-Ag were added to prepare composite films. The physicochemical characteristics and microstructure of the films were studied. The results showed that the addition of TiO₂-Ag significantly increased the water solubility of the film. When the TiO₂-Ag concentration was increased to 0.5%, the film had the best antibacterial ability and the lowest light transmittance (54.6%), but the tensile strength of the film was the lowest, decreased from 17.39 MPa to 9.014 MPa. The water vapor permeability of film first decreased and then increased, and the minimum value was 2.63 × 10^-12 g·cm/cm²·s·Pa when the concentration of TiO₂-Ag was 0.4%. XRD, XPS, and ATR-FTIR results showed that the presence of TiO₂-Ag crystals in the film could enhance the interaction between the components, and FE-SEM results showed that the film had a very smooth and uniform surface. In general, FG/Ch/TiO₂-Ag composite film is expected to be used in the food packaging industry.

Chitosan-TiO2: A Versatile Hybrid Composite

In recent years, a strong interest has emerged in hybrid composites and their potential uses, especially in chitosan–titanium dioxide (CS–TiO₂) composites, which have interesting technological properties and applications. This review describes the reported advantages and limitations of the functionalization of chitosan by adding TiO₂ nanoparticles. Their effects on structural, textural, thermal, optical, mechanical, and vapor barrier properties and their biodegradability are also discussed. Evidence shows that the incorporation of TiO₂ onto the CS matrix improves all the above properties in a dose-dependent manner. Nonetheless, the CS–TiO₂ composite exhibits great potential applications including antimicrobial activity against bacteria and fungi; UV-barrier properties when it is used for packaging and textile purposes; environmental applications for removal of heavy metal ions and degradation of diverse water pollutants; biomedical applications as a wound-healing material, drug delivery system, or by the development of biosensors. Furthermore, no cytotoxic effects of CS–TiO₂ have been reported on different cell lines, which supports their use for food and biomedical applications. Moreover, CS–TiO₂ has also been used as an anti-corrosive material. However, the development of suitable protocols for CS–TiO₂ composite preparation is mandatory for industrial-scale implementation.