Impact of citrus pectin on the foaming behavior, structures, and barrier properties of the starch foam blocks.

The starch foam displays weak barrier properties under humid storage, which limits its applications in the food industry. In this study, citrus pectin was loaded to strengthen the starch foam. Results showed that the pectin (4 wt% âˆ¼ 8 wt%) effectively modified the cell structures of the starch foam block. This was attributed to the increased viscosity of the starch melt during foaming and the enhanced cell stability during cooling, which was promoted by the formation of entanglements, hydrogen bonds, and ester bonds between pectin and starch, as confirmed by FTIR and DSC. Moreover, the pectin-starch foam displayed improved mechanical properties under wet storage conditions, mainly due to the limited moisture adsorption and water migration. The foam containing 4 wt% of pectin exhibited the highest compression-recovery ratio (76.7 %) and a reduced adsorbed moisture content (19.22 %) under 95 % RH. Overall, citrus pectin could improve the starch foaming process and the foam blocks barrier properties.

Strategies for the incorporation of organosolv lignin in hydroxypropyl methylcellulose-based films: A comparative study.

Organosolv lignin extracted from vine pruning residues was added to hydroxypropyl methylcellulose (HPMC)-based films using three strategies: i) lignin incorporated into the film (lignin-based film), ii) lignin nanoparticles (LNPs) incorporated into the film (LNPs-based film), and iii) lignin coated on HPMC films' surface (lignin-coated film). The films obtained were evaluated in terms of morphology, water barrier and mechanical properties, and antioxidant capacity. Results showed that LNPs incorporation did not affect the films´ water vapour permeability (WVP). Nonetheless, the lignin-based and lignin-coated films improved the water barrier properties of HPMC-based films, achieving a 31.5 and 36 % reduction of WVP, respectively. The morphological evaluation, performed by scanning electron microscopy, revealed films' morphology changes with the lignin incorporation, which was more evident in the lignin-based films. Fourier transform infrared spectroscopy (FTIR) showed minor changes in the film's structure using the different lignin incorporation methods. The mechanical properties were improved, including a significant increase in the tensile strength in the lignin-based and lignin-coated films. All films showed high radical scavenging activity (RSA) after 24 h, with a gradual increase in the lignin-coated films over time. The lignin-coated films showed to be the most promising incorporation strategy to improve the HPMC-based film's properties.

Flexible and Recyclable Bio-Based Polyester Composite Films with Outstanding Mechanical and Gas Barrier Properties Using Leaf-Shaped CNT@BNNS Covalent Heterojunction.

With the depletion of petroleum resources, the development of sustainable alternatives for plastic substitutes has grown in importance. It is urgently desirable yet challenging to design high-performance polyesters with extensive mechanical and prominent gas barrier properties. This work uses bio-based PBF polyester as a matrix, "leaf-shaped" carbon nanotube@boron nitride nano-sheet (CNT@BNNS) covalent hetero-junctions as functional fillers, to fabricate CNT@BNNS/PBF (denoted as CBNP) composite films through an "in-situ polymerizing and hot-pressing" strategy. The covalent CNT "stem" suppresses the re-stacking of BNNS "leaf", endowing hetero-structured CNT@BNNS illustrates superior stress transfer and physical barrier effect. The covalently hetero structure and high orientation degree of CNT@BNNS greatly improve the comprehensive performance of the CBNP composites, including excellent mechanical (strength of 76 MPa, modulus of 2.3 GPa, toughness of 85 MJ m-3, elongation at break of 193%) and gas barrier (O2 of 0.015 barrer, and H2O of 1.1 × 10-14 g cm cm-2 s-1 Pa-1) properties that are much higher than for pure PBF or other-type polyesters, and most engineering plastics. Moreover, the CBNP composites also boast easy recyclability, overcoming the tradeoff between high performance and easy recycling of traditional plastics, which makes the polyester composite competitive as a plastic substitute.

Janus GO/BTA/PMMA Microcapsules for Biobased Self-Healing Anticorrosion Coatings with Ultrahigh Performance.

The giant reduction of the barrier properties due to self-healing microcapsules and the lack of real-time protection during the healing remained the main challenges in self-healing anticorrosion coatings. Herein, a facile strategy using Janus graphene oxide (GO) as a dense and flexible shell has been proposed to synergistically solve these challenges. Benzotriazole (BTA) was used to synthesize Janus GO at the oil-water interface, and Janus GO/BTA/poly(methyl methacrylate) microcapsules were prepared. Energy-dispersive X-ray spectroscopy, Fourier infrared spectroscopy, Raman spectroscopy, and ultraviolet spectrophotometer analysis confirmed the formation of a Janus GO structure with one surface hydrophilic and the other hydrophobic. The surface morphology of J-GO-capsules with a high GO coverage rate was observed by scanning electron microscopy. The high biobased content coating containing J-GO-capsules showed a low-frequency impedance value above 1010 as assessed by electrochemical impedance spectroscopy after being immersed in 3.5 wt % NaCl solution for 60 days. In addition, the low-frequency impedance values of the coating were maintained after being scratched due to the self-healing properties of the J-GO-capsules as well as the real-time protective effect of the BTA. Biobased coatings with the best overall properties among all of the self-healing anticorrosion coatings were prepared.

Antimicrobial gelatin-based films with cinnamaldehyde and ZnO nanoparticles for sustainable food packaging.

Cinnamaldehyde (CIN), a harmless bioactive chemical, is used in bio-based packaging films for its antibacterial and antioxidant properties. However, high amounts can change food flavor and odor. Thus, ZnO nanoparticles (NPs) as a supplementary antimicrobial agent are added to gelatin film with CIN. The CIN/ZnO interactions are the main topic of this investigation. FTIR-Attenuated Total Reflection (ATR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to investigate CIN/ZnO@gelatin films. Transmission electron microscope (TEM) images revealed nanospheres morphology of ZnO NPs, with particle sizes ranging from 12 to 22 nm. ZnO NPs integration increased the overall activation energy of CIN/ZnO@gelatin by 11.94%. The incorporation of ZnO NPs into the CIN@gelatin film significantly reduced water vapour permeability (WVP) of the CIN/ZnO@gelatin film by 12.07% and the oxygen permeability (OP) by 86.86%. The water sorption isotherms of CIN/ZnO@gelatin were described using Guggenheim-Anderson-de Boer (GAB) model. The incorporation of ZnO NPs into the CIN@gelatin film reduced monolayer moisture content (M0) by 35.79% and significantly decreased the solubility of CIN/ZnO@gelatin by 15.15%. The inclusion of ZnO into CIN@gelatin film significantly decreased tensile strength of CIN/ZnO@gelatin by 13.32% and Young`s modulus by 18.33% and enhanced elongation at break by 11.27%. The incorporation of ZnO NPs into the CIN@gelatin film caused a significant decrease of antioxidant activity of CIN/ZnO@gelatin film by 9.09%. The most susceptible organisms to the CIN/ZnO@gelatin film included Candida albicans, Helicobacter pylori, and Micrococcus leutus. The inhibition zone produced by the CIN/ZnO@gelatin film versus Micrococcus leutus was 25.0 mm, which was comparable to the inhibition zone created by antibacterial gentamicin (23.33 mm) and cell viability assessment revealed that ZnO/CIN@gelatin (96.8 ± 0.1%) showed great performance as potent biocompatible active packaging material.

Ultrasound-Assisted Extrusion Compounding of Nano Clay/Polypropylene Nano Compounds.

The incorporation of nanoparticles can significantly enhance the properties of polymers. However, the industrial production of nanocomposites presents a technological challenge in achieving the proper dispersion of nanoparticles within the polymer matrix. In this work, a novel device is presented that can be seamlessly integrated with standard twin-screw extruders, enabling the application of ultrasonic vibration to molten polymeric material. The primary objective of this study is to experimentally validate the effectiveness of this technology in improving the dispersion of nanoparticles. To accomplish this, a comparative analysis was carried out between nanocomposites obtained through conventional compounding extrusion and those processed with the assistance of ultrasonic vibrations. The nanocomposites under investigation consist of a polypropylene (PP) matrix reinforced with nano clays (Cloisite 20A) at a target loading ratio of 5% by weight. To comprehensively evaluate the impact of the ultrasound-assisted compounding, various key properties were assessed, such as the melt flow index (MFI) to characterize the flow behavior, mechanical properties to evaluate the structural performance, oxygen barrier properties to assess potential gas permeability, and microstructure analysis using Scanning Electron Microscopy (SEM) for detailed morphology characterization. The results suggested an improvement in nanoparticle dispersion when using the ultrasound device, particularly when the intensity was adjusted to 60%.

Preparation of multi-barrier and multi-functional paper-based materials by chitosan, ethyl cellulose and green walnut husk biorefinery products for sustainable food packaging.

The growing interest in paper-based materials for packaging is driven by their renewable and eco-friendly characteristics. However, their poor barrier performance against water, oil, and gas limits their application in the food packaging industry. In this study, we developed a simple dual-layer coating method to create water- and oil-repellent, gas barrier, antioxidant, and antibacterial paper-based materials using naturally-derived materials, including chitosan (CS), ethyl cellulose (EC), and cascade biorefinery products from green walnut husk (GWHE and CNC). The bottom CS/CNC oil-resistant coating and the top EC/GWHE water-resistant coating were applied to the paper surface. The synergistic effect of these coatings enhances the gas barrier and imparts functional properties to the paper. Compared to uncoated paper, the dual-layer-coated paper demonstrated a 239.1 % increase in tensile index, a higher kit rating value of 12/12, a lower Cobb 60 value of 3.21 mg/m2, a 44.0 % decrease in water vapor permeability (WVP), and a 90.7 % reduction in air permeability (AP). Additionally, this coated paper exhibited good antioxidant and antibacterial properties and favorable biodegradability. This study provides novel insights into the valorization of GWH waste and presents a sustainable strategy for producing high-performance paper-based materials for food packaging applications.

Improved moisture barrier and mechanical properties of rice protein/sodium alginate films for banana and oil preservation: Effect of the type and addition form of fatty acid.

Attenuating the moisture sensitivity of hydrophilic protein/polysaccharide-based films without impairing other properties remains a challenge. Fatty acid dispersed in Pickering emulsion was proposed to overcome such issue. An increase in fatty acid chain length slightly reduced the water vapor permeability (WVP) of emulsion films. As the number of fatty acid double bonds increased from 0 to 1, the WVP of emulsion films was significantly decreased by 14.02% while mechanical properties were significantly enhanced. More hydrogen bonds and stronger electrostatic interactions in the presence of fatty acids were observed by molecular dynamics simulation. The weight loss of bananas coated with oleic acid-incorporated film-forming emulsion was 6.81% lower than that of uncoated group after 4 days, and the corresponding film was more effective to delay oil oxidation than the commercial polypropylene film, indicating that the film is a promising alternative to food coating and packaging material.

Benefits of Incorporating Lignin into Starch-Based Films: A Brief Review.

Polysaccharides are an excellent renewable source for developing food-packing materials. It is expected that these packages can be an efficient barrier against oxygen; can reduce lipid peroxidation, and can retain the natural aroma of a food commodity. Starch has tremendous potential to be explored in the preparation of food packaging; however, due to their high hydrophilic nature, packaging films produced from starch possess poor protective moisture barriers and low mechanical properties. This scenario limits their applications, especially in humid conditions. In contrast, lignin's highly complex aromatic hetero-polymer network of phenylpropane units is known to play a filler role in polysaccharide films. Moreover, lignin can limit the biodegradability of polysaccharides films by a physical barrier, mainly, and by non-productive bindings. The main interactions affecting lignin non-productive bindings are hydrophobic interactions, electrostatic interactions, and hydrogen-bonding interactions, which are dependent on the total phenolic -OH and -COOH content in its chemical structure. In this review, the use of lignin as a reinforcement to improve the biodegradability of starch-based films in wet environments is presented. Moreover, the characteristics of the used lignins, the mechanisms of molecular interaction among these materials, and the sensitive physicochemical parameters for biodegradability detection are related.

Fully Bio-Based Blends of Poly (Pentamethylene Furanoate) and Poly (Hexamethylene Furanoate) for Sustainable and Flexible Packaging.

In the present study, bio-based polymeric blends have been prepared for applications in the field of sustainable food packaging, starting from two furan-based homopolymers, poly(hexamethylene 2,5-furanoate) (PHF) and poly(pentamethylene 2,5-furanoate) (PPeF). PHF and PPeF were synthesized by two-step melt polycondensation-a solvent-free synthetic strategy-and then binary physical mixtures, PHF/PPeF, with different weight compositions were prepared by dissolution in a common solvent. The blends were processed into compression-moulded films, and molecular, morphological, structural, thermal, and mechanical characterizations were subsequently carried out. Blending did not negatively affect the thermal stability of the parent homopolymers, and good compatibility between them was observed. This strategy also allowed for the modulation of the chain rigidity as well as of the crystallinity, simply by acting on the relative weight amount of the homopolymers. From a mechanical point of view, the presence of PPeF led to a reduction in stiffness and an increase in the elongation at break, obtaining materials with an elastomeric behaviour. Evaluation of the gas barrier properties confirmed that the good barrier properties of PHF were preserved by blending. Finally, lab-scale composting tests confirmed a greater weight loss of the mixtures with respect to the PHF homopolymer.

Development of Functional Composite Edible Films or Coatings for Fruits Preservation with Addition of Pomace Oil-Based Nanoemulsion for Enhanced Barrier Properties and Caffeine for Enhanced Antioxidant Activity.

The aim of this study was to develop functional composite edible films or coatings for fruit preservation by the addition of bioactive components in combinations that have not yet been thoroughly studied, according to the relevant literature. Edible films were initially composed of (i) chitosan (CH), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio), and (ii) hydroxypropyl methylcellulose (HPMC), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio). The bioactive components incorporated (5, 10 and 15% v/v) were as follows: (i) pomace oil-based nanoemulsion (NE) aiming to enhance barrier properties, and (ii) caffeine (C), aiming to enhance the antioxidant activity of films, respectively. Indeed, NE addition led to very high barrier properties (low oxygen and water vapor permeability), increased flexibility and reduced color. Furthermore, the contribution of these coatings to fresh strawberries' preservation under cold storage was investigated, with very promising results concerning weight loss, color difference, and preservation of fruit moisture and quantity of O2 and CO2 inside the packages. Additionally, C addition led to very high antioxidant activity, reduced color and improved barrier properties. Finally, the contribution of these coatings to avocado's preservation under cold storage was investigated, with very encouraging results for color difference, hardness and peroxide value of the fruit samples.

Development of alginate film filled with halloysite-carbon dots for active food packaging.

The development of functional bionanocomposites for active food packaging is of current interest to replace non-biodegradable plastic coatings. In the present work, we report the synthesis of an alginate-based nanocomposite filled with modified halloysite nanotubes (HNTs) to develop coatings with improved barrier properties for food packaging. Firstly, HNTs were chemically modified by the introduction of carbon dots units (CDs) onto their external surface (HNTs-CDs) obtaining a nanomaterial where CDs are uniformly present onto the tubes as verified by morphological investigations, with good UV absorption and antioxidant properties. Afterwards, these were dispersed in the alginate matrix to obtain the alginate/HNTs-CDs nanocomposite (Alg/HNTs-CDs) whose morphology was imaged by AFM measurements. The UV and water barrier properties (in terms of moisture content and water vapor permeability) were investigated, and the antioxidant properties were evaluated as well. To confer some antimicrobial properties to the final nanocomposite, the synthetized filler was loaded with a natural extract (E) from M. cisplatensis. Finally, the extract kinetic release both from the filler and from the nanocomposite was studied in a medium mimicking a food simulant and preliminary studies on the effect of Alg/HNTs-CDs/E on coated and uncoated fruits, specifically apples and bananas were also carried out.

Confinement Effect in Multilayer Films Made from Semicrystalline and Bio-Based Polyamide and Polylactic Acid.

Bio-based multilayer films were prepared by using the innovative nanolayer coextrusion process to produce films with a number of alternating layers varying from 3 to 2049. For the first time, a semicrystalline polymer was confined by another semicrystalline polymer by nanolayering in order to develop high barrier polyamide (PA11)/polylactic acid (PLA) films without compromising thermal stability and mechanical behavior. This process allows the preparation of nanostratified films with thin layers (down to nanometric thicknesses) in which a confinement effect can be induced. The stratified structure has been investigated, and the layer thicknesses have been measured. Barrier properties were successfully correlated to the microstructure, as well as the thermal behavior, and mechanical properties. The layer continuity was fully achieved for most of the films, but some layer breakups have been observed on the film with the thinnest PLA layer (2049-layers film). Coextruding PLA with PA11 has induced an increase in PLA crystallinity (from 4 to 16%) along with an increase in thermal stability of the multilayer films without impacting PA11 properties. Gas barrier properties were driven by the PLA confined layers due to the microstructural rearrangement by increasing crystallinity, whereas water barrier properties were governed by the PA11 confining layers due to its lower water affinity. As a consequence, a decrease of water permeability (up to 11 times less permeable for the 6M film) but an increase of gas barrier properties (barrier improvement factor (BIF) of 66% for the 0M film for N2 and BIF of 36% for the 6M film for CO2 for instance) were evidenced as the layer number was increased. This study paves the way for the development of ecofriendly materials with outstanding barrier performances and highlights the importance of nonmiscible polymers adhesion at melt state and additives presence.

Incorporation of Nano-Zinc Oxide as a Strategy to Improve the Barrier Properties of Biopolymer-Suberinic Acid Residues Films: A Preliminary Study.

Finishing coatings in the wood-based composites industry not only influence the final appearance of the product but also serve to protect against fungi and molds and reduce the release of harmful substances, particularly formaldehyde and volatile organic compounds (VOCs). Carbon-rich materials, such as those derived from birch bark extraction, specifically suberin acids, can fulfill this role. Previous research has demonstrated that adding suberin acid residues (SAR) at 20% and 50% by weight significantly enhances the gas barrier properties of surface-finishing materials based on poly(lactide) (PLA) and polycaprolactone (PCL), particularly in terms of total VOC (TVOC) and formaldehyde emissions. This study aims to explore whether these properties can be further improved through the incorporation of nano-zinc oxide (nano-ZnO). Previous research has shown that these nanoparticles possess strong resistance to biological factors and can positively affect the characteristics of nanofilms applied as surface protection. The study employed PLA and PCL finishing layers blended with SAR powder at 10% w/w and included 2% and 4% nano-zinc oxide nanoparticles. The resulting blends were milled to create a powder, which was subsequently pressed into 1 mm-thick films. These films were then applied to raw particleboard surfaces. TVOC and formaldehyde emission tests were conducted. Additionally, the fungal resistance of the coated surfaces was assessed. The results showed that PLA/SAR and PCL/SAR composites with the addition of nano-zinc oxide nanoparticles exhibited significantly improved barrier properties, offering a promising avenue for developing biodegradable, formaldehyde-free coatings with enhanced features in the furniture industry. Furthermore, by utilizing SAR as a post-extraction residue, this project aligns perfectly with the concept of upcycling.

Multilayer Film Comprising Polybutylene Adipate Terephthalate and Cellulose Nanocrystals with High Barrier and Compostable Properties.

In the present study, a multilayer, high-barrier, thin blown film based on a polybutylene adipate terephthalate (PBAT) blend with polyhydroxyalkanoate (PHA), and composed of four layers including a cellulose nanocrystal (CNC) barrier layer and an electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) hot-tack layer, was characterized in terms of the surface roughness, surface tension, migration, mechanical and peel performance, barrier properties, and disintegration rate. The results showed that the film exhibited a smooth surface. The overall migration tests showed that the material is suitable to be used as a food contact layer. The addition of the CNC interlayer had a significant effect on the mechanical properties of the system, drastically reducing the elongation at break and, thus, the flexibility of the material. The film containing CNCs and electrospun PHBV hot-tack interlayers exhibited firm but not strong adhesion. However, the multilayer was a good barrier to water vapor (2.4 ± 0.1 × 10-12 kg·m-2·s-1·Pa-1), and especially to oxygen (0.5 ± 0.3 × 10-15 m3·m-2·s-1·Pa-1), the permeance of which was reduced by up to 90% when the CNC layer was added. The multilayer system disintegrated completely in 60 days. All in all, the multilayer system developed resulted in a fully compostable structure with significant potential for use in high-barrier food packaging applications.

Water-resistant and barrier properties of poly(vinyl alcohol)/nanocellulose films enhanced by metal ion crosslinking.

Polyvinyl alcohol (PVA) is a promising alternative to non-biodegradable flexible packaging materials, and nanocellulose is often used to enhance the properties of PVA films, but the composite films still have poor water resistance and barrier properties. To address this issue, iron ions (Fe3+) were introduced into PVA/cellulose nanofibrils (CNF) films, and Fe3+ formed coordination bonds with carboxyl and hydroxyl groups on the surface of CNF and PVA chains. Therefore, constructing a strong coordination crosslinking network within the film and improving the interfacial interaction between PVA and CNF. The water resistance, mechanical and barrier properties of the crosslinked films were significantly improved. Compared with the un-crosslinked film, the oxygen transmission rate (OTR) was decreased by up to 67 %, and the water swelling ratio was significantly reduced from 1085 % to 352 %. The tensile strength of the film with 1.5 wt% Fe3+ reached 41.93 MPa, which was 62 % higher than that of the un-crosslinked film. Furthermore, the composite film demonstrated good recyclability, almost recovering its original mechanical properties in two recycling tests. This simple and effective method for preparing water resistance and barrier films shows potential applications in flexible packaging areas.

Development of PBS/Nano Composite PHB-Based Multilayer Blown Films with Enhanced Properties for Food Packaging Applications.

Biobased and biodegradable plastics have emerged as promising alternatives to conventional plastics offering the potential to reduce environmental impacts while promoting sustainability. This study focuses on the production of multilayer blown films with enhanced functional properties suitable for food packaging applications. Films were developed through co-extrusion in a three-layer film configuration, with Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) as the external and internal layers, respectively. The functional layer consisted of Polyhydroxybutyrate (PHB) enhanced with nanoclays Cloisite® 30B at varying weight ratios. Films were also processed by manipulating the extruder screw speed of the functional layer to investigate its impact on the functional properties. Rheology, mechanical strength, and barrier performance were characterised to establish correlations between processing conditions and functional layer blends (Cloisite® 30B/PHB) on the properties of the resultant films. Rheological test results indicated that the system with 5% Cloisite® had the best polymer/nanofiller matrix dispersion. Mechanical and permeability tests showed that by varying the process conditions (the alteration of the thickness of the functionalized layer) resulted in an improvement in mechanical and barrier properties. Furthermore, the addition of the nanofiller resulted in a stiffening of the film with a subsequent decrease in permeability to oxygen and water vapour.

Changes in the properties of the corn starch glycerol film in a time-dependent manner during gelatinization.

This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of corn starch and glycerol. Changes in the microstructure were analyzed to understand how they relate to the physical and chemical properties of these films. Specifically, we found that increasing the gelatinization time decreased the film thickness, solubility, water vapor permeability, and maximum degradation temperature and increased the water content. A gradual increase in the water contact angle of the corn starch-glycerol films was observed with increasing gelatinization time. This trend is likely due to the disruptive effect of gelatinization on the crystalline and amorphous structures inherent in corn starch, resulting in reduced film crystallinity, degree of order (DO) and degree of double helix (DD).

Bioactive composite films with improved antioxidant and barrier properties prepared from sodium alginate and deep eutectic solvent treated distillers' grains.

In this work, a straightforward approach utilizing distillers' grains (DG) waste and sodium alginate (SA) was developed to prepare functional and bioactive packaging films. Deep eutectic solvents (DESs) were initially synthesized from choline chloride (CO), betaine (BO), glycerol (GO), and oxalic acid. Composite films were then prepared from DES-treated DG slurry and SA at different ratios. Characterization and analysis revealed that adding 75 % CO-treated DG slurry reduced the water vapor permeability (WVP) by over 66 % compared to that of the SA film. Composite films containing CO/BO-treated DG slurry had an ultraviolet light barrier rate exceeding 99 %, while those with 75 % DES-treated DG slurry demonstrated excellent antioxidant activity, with a 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging rate of 80.14 %-88.35 %, representing a 322.45 %-365.73 % increase compared to that of the pure SA film. These composite films also exhibited favorable mechanical properties (31.58 MPa, 5.53 % EB), thermal stability, and biodegradability, extending the shelf life of grapes by 1.8 times. In conclusion, bioactive composite films derived from DES-treated DG are expected to replace petroleum-based plastics, enhancing sustainable biomass use and environmental responsibility.

Effect of ohmic heating on the structure and properties of flexible multilayer packaging.

Food-packaging-processing interactions define packaging materials' performance properties and product quality. This study evaluated the effect of ohmic heating (OH) processing and different food simulants on the properties of four multilayer flexible packaging materials (PETmet/PE, PETmet/PP, PET/Al/PE, and PET/Al/PA/PP). OH treatment was applied to the sealed packages containing the food simulants using a voltage gradient of 3.7 V/cm at a frequency of 20 kHz, resulting in a thermal process of at 80 °C for 1 min. The structure and performance of the different packages were then evaluated. The materials did not show changes in chemical groups nor thermal properties. However, the simulant-packaging-processing interaction resulted in changes in crystallinity, morphology, mechanical and barrier properties (water and oxygen), especially for metallized films in contact with acidic food simulants. The results indicate that although OH resulted in changes in packaging materials, these materials can be used under the conditions applied in this study.