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In this study, nanocomposites of polylactic acid (PLA) with clove essential oil (CEO) and alkali treated halloysite nanotubes (NHNT) as fillers were synthesized by using simple solvent casting method. The treatment of halloysite nanotubes with NaOH increased the surface area from 50.16 m 2 ⋅g -1 to 57.01 m 2 ⋅g -1 and pore volume from 0.25 cm 3 ⋅g -1 to 0.32 cm 3 ⋅g -1 . The as-synthesized nanocomposite films were characterized for physical, thermal, mechanical and water vapor barrier properties towards their use as food packaging material. The nanocomposite film PCOH0.5 (consisting 0.5 wt% NHNT and 200 μL CEO) possessed the best physical properties with percentage enhancements over PLA as: surface hydrophobicity (20.2 %), water vapor barrier (42.1 %), thermal stability (3.2 %), flexibility (682 %), tensile strength (20 %), elastic modulus (38 %), UV barrier property (62 %). In addition, a practical packaging test was performed on cut apples stored at room temperature for 6 days. The PCOH0.5 films showed substantially improved results (as compared to PLA) as follows: weight loss (40.5 %), mesophilic count (4.0 %), firmness (116.6 %), titratable acidity (110.8 %), pH (2.9 %) and total soluble solids (8.9 %). The results clearly indicate the efficiency of PLA/CEO/NHNT nanocomposite films as potential active food packaging material., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Electrosprayed zein nanoparticles containing 10% (w/w) of clove essential oil (CEO) were prepared and then with different levels (5, 10, and 15% w/w) in the starch matrix were used. The incorporation of zein nanoparticles in the structure of starch-based bio-nanocomposites films was confirmed by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Increasing the level of application of zein bio-nanofillers in the starch film matrix increased thickness and contact angle. However, the use of electrosprayed zein nanoparticles loaded by CEO (EZN-CEO) up to 10% significantly (p < 0.05) reduced the water vapor permeability (WVP), but using 15% of the nanoparticles increased the WVP of the films significantly (p < 0.05). Increasing the EZN-CEO up to 10% significantly (p < 0.05) increased the tensile strength and Young's modulus and reduced the elongation at break of the films. Sustained release of CEO from the bio-nanocomposites showed that the most release of the CEO occurs in 10% ethanol medium. The Fickian diffusion was the predominant mechanism in the release of the CEO, and the Peleg model was selected as the best one to explain the release behavior. The structures designed in this study can be used as an edible coating and bio-preservative in perishable food products., Competing Interests: Declaration of competing interest The authors wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2021. Published by Elsevier B.V.)

A novel antioxidative film was prepared by drying a film-forming solution containing the Flos Sophorae Immaturus extract (FSIE) (0-3.5%) and cassia gum (CG). Scanning electron microscopy (SEM) showed that FSIE was successfully compounded with CG. Although the addition of FSIE slightly increased the water vapor permeability (WVP) and O 2 permeability (OP) of the film, it also improved its ability to block ultraviolet light significantly. The appropriate amounts of FSIE increased the tensile strength (TS) from 20.9 MPa to 30.2 MPa but reduced the elongation at break (EB) from 38.7% to 27.6%. The films doped with FSIE exhibited strong antioxidative activity and high rates of free radical scavenging. Total phenols exhibited a positive trend as the amount of FSIE increased in 50% of ethanol. The practical application of these composite films was investigated by evaluating the quality of lard wrapped in the films. After 25 d, the acid value (X AV ) and peroxide value (POV) of lard packaged in CG/FSIE2% were lower than the values for lard packaged in CG/FSIE0% and plastic bag. These results showed that the CG/FSIE film had superior antioxidative activity compared to films made from plastic and pure CG., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Alginate nanocomposite films incorporating sepiolite (Sep) modified with myrtle berries extract (MBE) rich in polyphenols were prepared by solution casting method. The effects of different extract concentrations on the film properties were determined by measuring physicochemical, mechanical and antioxidant properties of the films. Fourier transform infrared (FTIR) spectra indicated that strong interactions between the polyphenols present in the MBE and sepiolite were involved in the films. The results suggested that incorporation of Sep-MBE hybrids into the films improved elongation at break, tensile strength, water vapor and UV barrier properties compared to the control film. The antioxidant activity of the films was significantly improved and raised with increasing content of MBE. The release kinetics results of MBE polyphenols from the active films into alcoholic food simulant indicated that the addition of Sep-MBE hybrids to alginate film is able to slow the release of MBE polyphenols. This study revealed the benefits of incorporation of Sep-MBE hybrids into the alginate films and their potential application as active packaging films or coating material., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, various amounts of nanoclay montmorillonite (MMT) and ZnO nanopowders were used to analyze the properties of biodegradable nanocomposites of cationic starch (CS). Nanocomposites are produced by solvent casting method. The structure of CS-MMT nanocomposite films that contain 3% montmorillonite was exfoliated and was proved by XRD test. New hydrogen bonds were successfully formed between the CS hydroxyl groups and nanofillers and this was proved by FTIR test. The water vapor permeability and the UV light transmittance of the nanocomposites reduced after the contents of MMT and ZnO increased. ∆E and opacity of the nanocomposites enhanced after the amount of ZnO increased. Tensile strength (TS) of nanocomposites increased after the incorporation of ZnO and MMT nanoparticles although the elongation at break was diminished. Results showed that the 3 and 0.7 wt% amounts of montmorillonite and ZnO nanopowders were sufficient in order to acquire a well-moderated mechanical behavior in plastic and elastic regions, and they also cause good improvements in barrier and optical properties., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Corn distarch phosphate-zein bilayer films (C-Z) fabricated from corn distarch phosphate-based films (C) laminated on zein-based films (Z) by thermocompression. The strong interaction between starch and zein molecules was formed by hydrogen bonding, which resulted in good thermal stability of bilayer films. Moreover, bilayer films exhibited better mechanical properties and ductility than monolayer Z films, and concomitantly enhanced the moisture barrier and oxygen barrier for monolayer C films. The tensile strength (TS) and elongation at break (EAB) of the C-Z bilayer films (the ratio C:Z was 6:4) increased by 74.04% and 348.13% over the Z films, respectively. Compared with C films, the water vapor permeability (WVP) and oxygen permeability (OP) of the C-Z bilayer films (the ratio C:Z was 6: 4) decreased by 31.53 and 24.26%, respectively., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this paper, carboxymethyl konjac glucomannan (CMKGM) was obtained by carboxyl modification of konjac glucomannan. Then CMKGM and chitosan (CS) were crosslinked and freeze-dried to prepare CMKGM/CS composite sponges with different proportions. The structure and micromorphology of CMKGM/CS sponges were investigated by FTIR spectroscopy and SEM. The SEM results showed that the pore structure of the composite sponge gradually increased with the increase of CMKGM content. To assess the applicability of CMKGM/CS composite sponges as wound dressing, the swelling behavior, water vapor transmission rate (WVTR), biocompatibility (cytotoxicity and hemolysis) were analyzed. The results indicated that CMKGM/CS composite sponges possessed high swelling ratio, proper WVTR and good biocompatibility, which might accelerate tissue regeneration. Meanwhile, in vivo experiments demonstrated that CMKGM/CS composite sponges could effectively heal full-layer wound of skin defects of male ICR mice., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Lupeol entrapped chitosan-gelatin hydrogel (LCGH) films were prepared by solution cast method by blending chitosan and gelatin solution using glycerol as plasticizer, followed by crosslinking with glutaraldehyde. LCGH films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), equilibrium water content (EWC), Water vapor transmission rate (WVTR) and in vitro release studies. SEM confirmed presence of the uniform porous network of both blank and LCGH films. The incorporation of lupeol in hydrogel was confirmed FTIR and DSC. The LCGH film was smooth, flexible, non-brittle and showed excellent swelling ability. EWC (85.40%) and WVTR (2228±31.8) met the condition of ideal wound dressing. The biological activity of lupeol was assessed by antioxidant and antibacterial assay. Antioxidant assay confirmed that lupeol and LCGH film have excellent antioxidant properties by scavenging both radicals at steady increasing rate which increases with time due to steady release of lupeol. Antibacterial activity of lupeol in LCGH film was found to be retained as assessed by disc diffusion method. Cell viability was evaluated by MTT assay with NIH/3T3 fibroblast cells. The MTT assay showed that the CGH film evidently offered acceptable cell viability and non-toxicity. These observations depicted that chitosan/gelatin hydrogel film can be an ideal delivery system for sustained released of lupeol and LCGH film for enhanced wound healing., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this work, the effect of hydrolyzed keratin on the properties of soy protein-based films was analyzed when different manufacture processes were employed. It is widely known that the processing method selected can affect the film properties as a function of the structure obtained during the film formation. Therefore, the assessment of hydrolyzed keratin/soy protein films processed by casting and compression moulding was carried out by means of the analysis of physicochemical, thermal, mechanical, optical and surface properties. It was observed that the incorporation of hydrolyzed keratin, obtained from a simpler, environmentally friendlier and more sustainable extraction method, resulted in the improvement of the thermal stability of the films, irrespective of the processing method employed. Moreover, the films processed by compression moulding showed enhanced tensile strength, which increased with the incorporation of hydrolyzed keratin due to the formation of disulfide bonds., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The increasing demand for bio-based materials to be used in food packaging has stimulated the development of novel, environmentally-friendly edible films. Antimicrobial films were developed by incorporating different levels of clove bud essential oil (0.5%, 1.0%, and 1.5%) into the citrus pectin in order to modify the functional properties of the films. Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry analysis (DSC) and X-ray diffraction (XRD) were performed, together with the determination of physical, optical, mechanical, antioxidant and antimicrobial properties of pectin emulsified films. The inclusion of oil significantly enhanced the water barrier properties of the films. Addition of oil leads to more opaque films with relatively heterogeneous microstructure, resulting in an increase in film opacity. The composite films were more resistant to breakage and more flexible than the control films. Differential scanning calorimetry (DSC) demonstrated that films incorporating CEO exhibited improved heat stability with slightly higher degradation temperature, compared with control films. The inhibitory effect of pectin films with CEO was also evaluated on three common foodborne bacteria. These results revealed that clove oil has a good potential to be incorporated into citrus pectin to make antimicrobial edible films or coatings for various food applications., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In current study, starch/TiO 2 bionanocomposites were produced by photochemical reactions as a biodegradable food packaging material. Physical, mechanical, thermal and water-vapor permeability properties were investigated. Then, the photo-degradation properties of nanocomposite films were studied. This is the first report of the photo-producible and photo-degradable bionanocomposite as a food packaging material. Film-forming solutions were exposed to ultraviolet A (UV-A) for different times. Our results showed that UV-A irradiation increased the hydrophobicity of starch films. With increasing UV-A exposure time, tensile strength and Young's modulus of the specimens were decreased. On the other hand, elongation at break of the films was increased with increasing UV-A irradiation. The glass transition temperature and melting point of the films were increased by increasing UV-A exposure time. Nevertheless, the results showed that photo-degradation properties of photo-produced starch/TiO 2 nanocomposite were significantly higher than virgin starch and virgin starch/TiO 2 films. According to obtain results and bibliography a schema was developed to describe the mechanism of photo-production and photo-degradation of starch/TiO 2 by UV-A ray. It can be concluded, the modification of starch based biopolymer by UV-A and nano-TiO 2 , is an easy and accessible process to improve the packaging properties and photo-degradability of biopolymer based films., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Novel biodegradable films were prepared by blending guar gum, chitosan and poly (vinyl alcohol) having mint (ME) and grapefruit peel (GE) extracts and crosslinked with nontoxic tetraethoxysilane (TEOS). The co-concentration effect of TEOS with natural extracts on the films was studied. FTIR analysis confirmed the presence of incorporated components and the developed interactions among the polymer chains. The surface morphology of the films by SEM showed the hydrophilic character due to porous network structure. The films having both ME and GE with maximum amount of crosslinker (100μL), showed maximum swelling (58g/g) and stability while the optical properties showed increased protection against UV light. This film sample showed compact network structure which enhanced the ultimate tensile strength (40.03MPa) and elongation at break (104.8%). ME/GE conferred the antioxidant properties determined by radical scavenging activity and total phenolic contents (TPC) as ME films have greater TPC compared to GE films. The soil burial test exhibited the degradation of films rapidly (6days) confirming their strong microbial activity in soil. The lower water vapour transmission rate and water vapour permeability showed better shelf life; hence, these biodegradable films are environmental friendly and have potential for food and other packaging., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Multi-layer film structures of poly(lactic acid) (PLA) and fish gelatin (FG), prepared using the solvent casting technique, were studied in an effort to produce bio-based films with low oxygen (OP) and water vapor permeability (WVP). The scanning electron microscopy (SEM) images of triple-layer film showed that the outer PLA layers are being closely attached to the inner FG layer to make continuous film. The OP of multi-layer film (5.02cm 3 /m 2 daybar) decreased more than 8-fold compared with that of the PLA film, and the WVP of multi-layer film (0.125gmm/kPah m 2 ) also decreased 11-fold compared with that of the FG film. Lamination with PLA profoundly increased the water resistance of the bare gelatin film. Meanwhile, the tensile strength of the triple-layer film (25±2.13MPa) was greater than that of FG film (7.48±1.70MPa). At the same time, the resulting film maintains high optical clarity. Differential scanning calorimetry (DSC) analysis also revealed that the materials were compatible showing only one T g which decreased with FG deposition. This material exhibits an environmental-friendliness potential and a high versatility in food packaging., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this research, potato starch and TiO2 nanoparticles (0.5, 1 and 2wt%) films were developed. Influences of different concentrations of TiO2 on the functional properties of nanocomposite films (water-related properties, mechanical characteristics, and UV transmittance) were investigated. XRD, FTIR, and DSC analyses were used to characterize the morphology and thermal properties of the films. The results revealed that TiO2 nanoparticles dramatically decreased the values of water-related properties (water vapor permeability: 11-34%; water solubility: 1.88-9.26%; moisture uptake: 2.15-11.18%). Incorporation of TiO2 led to a slight increment of contact angle and tensile strength, and a decrease in elongation at break of the films. TiO2 successfully blocked more than 90% of UV light, while opacity and white index of the films were enhanced. Glass transition temperature and melting point of the films were positively affected by the addition of TiO2 nanoparticles. The result of XRD study exhibited that due to a limited agglomeration of TiO2 nanoparticles, the mean crystal size of TiO2 increased. Formation of new hydrogen bonds between the hydroxyl groups of starch and nanoparticles was confirmed by FTIR spectroscopy. In conclusion, TiO2 nanoparticles improved the functional properties of potato starch film and extended the potential for food packaging applications., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Although PLA is much more expensive than polyolefins, such as PP and PE, there is a great interest to propose PLA based material as alternative films for food packaging being PLA derivable from natural source, compostable and biodegradable. For this purpose the research has the task to investigate and propose PLA materials with enhanced properties to be effectively and efficiently alternative to polyolefin films for food packaging application. In this contribution, biocomposite films of PLA with 1, 3 and 5wt% of ZnO have been investigated to determine mechanical, barrier and antimicrobial (against Escherichia coli) properties. It is found that the biocomposite films are characterized by a good dispersion of the ZnO particles in PLA matrix, although no previous treatment was performed on ZnO particles, such as silanization, to decrease its incompatibility with the polymer. The biocomposite films have shown good mechanical properties, decrease of permeability to CO2 and O2, and only a slight increase to water vapour. Particularly important is that, for the biocomposite with 5wt% of ZnO, the % Reduction for E. Coli test reached the value of 99.99 already after 24h., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Composite nanofibers derived from synthetic and natural polymers normally show desirable characteristics in biomedical applications. In this study, composite nanofibrous mats (denoted as CNMs) with diameters of around 300 nm were fabricated facilely using blends of chitosan, gelatin and shape memory polyurethane (SMPU) by electrospinning and subsequent post-treatment with a silver nitrate solution. The obtained CNMs have shape memory effect and show desirable water vapor transmission ratio, surface wettability, satisfactory biological properties including antibacterial activity against the common Gram-negative and Gram-positive bacteria, cytocompatibility demonstrated to fibroblast, and the hemostatic property through a whole-blood clotting test. In addition, such CNMs can possibly benefit the wound healing through shape fixation-assisted easy processing and shape recovery-assisted closure of cracked wounds, which can be fine-tuned by pre-programming. Therefore, the CNMs presented in this study can be used as potential smart wound dressings., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Sugars were incorporated into CWFG solutions at different ratios (0%, 2%, 4%, and 6% w/w). Functional properties of the modified films were characterized following American standard test methods, and moisture sorption isotherm was characterized by polynomial and GAB models. Permeation to water vapor and oxygen of the modified films decreased compared to that of the control CWFG films. Moisture content, solubility, and monolayer water content of CWFG films decreased with the increase of sugar content. The addition of sugars significantly increased the Tensile strength of CWFG films from 30 to 40 MPa for ribose, and 30 to 35 MPa for fructose whereas elongation at the breaks decreased from 60% to 30% for ribose, and from 60% to 45% for that which incorporated fructose sugars. Moisture sorption isotherm curve significantly shifted to lower moisture content in aw<0.6. In aw>0.6, ribose-incorporated CWFG films, had similar function to hydrogel materials. In all the characterizations, the effects of ribose were significantly higher than those of fructose. Results of this research can be explored for commercial use, depending on the application for either packaging purposes or in the cosmetics industries., (Copyright © 2015 Elsevier B.V. All rights reserved.)