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Red grape pomace was used as a source for poly(3-hydroxybutyrate) (PHB) production, which was then subject to a range of purification processes. The different PHB biopolymers were characterized for chemical structure, crystallinity, thermal properties, colour, release of compounds into different food simulants and antioxidant inhibition, and comparisons were made with a commercially available PHB. An increase in purification steps did not have a significant effect on the high thermal stability of the extracted biopolymer, but it decreased the degree of crystallinity and the presence of amino acids and aromatic compounds. With additional purification, the PHB powders also whitened and the number of components released from the biopolymer into food simulants decreased. The released compounds presented antioxidant inhibition, which has not been previously reported in the literature or with commercially available polyhydroxyalkanoates. This is of great interest for food packaging and biomedical industries where the addition of antioxidant additives to improve PHB functional properties may not be necessary and could be avoided. [Display omitted] • Red grape pomace was used as a source for poly(3-hydroxybutyrate) (PHB) production. • The extracted PHB was then subject to a range of purification processes. • Crystallinity reduction was observed with further purification steps. • Aromatic impurities found in PHB migrated into hydrophilic food simulants. • The migrated impurities showed antioxidant activity. [ABSTRACT FROM AUTHOR]

This work involves preparing zinc manganite nanoparticles (ZnMn 2 O 4 NPs) using the Sol-gel method. Polymer nanocomposites of polyvinyl alcohol (PVA)/Sodium alginate (NaAlg)- ZnMn 2 O 4 NPs were created using the solution casting technique. The polymer nanocomposites films were made with varying weight percentages of ZnMn 2 O 4 nanoparticles. With the addition of nanofiller, the reduced direct and indirect energy band gap values and increased Urbach energy values were discovered in the UV–Vis data. XRD data showed a reduction in crystallinity degree with dopant. ZnMn 2 O 4 NPs had a strong interaction with PVA/NaAlg blend, as confirmed by FTIR. The addition of ZnMn 2 O 4 NPs led to improved thermal stability of the polymer nanocomposites films. Additionally, the nanocomposites films' mechanical characteristics were examined. The loading of ZnMn 2 O 4 nanoparticles has been associated with an increasing trend in the mechanical properties of the nanocomposites, including its toughness, Young's modulus, Tensile strength (Ts), and elongation. The antibacterial activity of the nanocomposites against fungus and bacteria was studied. Additionally, PVA/NaAlg-ZnMn 2 O 4 nanocomposites films had good antibacterial characteristics against environmental microorganisms such as Gram-positive (G+) S. aureus and Gram-negative(G−) E. coli bacteria as well as fungi C. albicans and A. niger. It was observed that the biodegradability of the nanocomposite films was lower compared to the pure PVA/NaAlg film. Compared to pure film, the water solubility was decreased upon the addition of ZnMn 2 O 4 NPs. After ZnMn 2 O 4 was added to the pure blend, the WVTR decreased. The produced polymer nanocomposites films appear to be a promising material for food packing, according to these results. [ABSTRACT FROM AUTHOR]

Chitosan (C) and zein (Z) were used to develop bilayer films with a characteristic one-way water barrier using a layer-by-layer (LBL) casting method. The effects of mass ratios (C:Z 1:1 , C:Z 1:2 , C:Z 1:3 , C:Z 3:1 , C:Z 2:1) on the microstructure and physicochemical properties of bilayer films were investigated. Bilayer films had uniform microstructures, and C:Z = 1:3 showed a firmer structure as the Z aggregates were distributed in the continuous phase of C. The intermolecular interactions between the C and Z layers were observed using FTIR and XRD analysis. TGA demonstrated that adding Z layer enhanced the thermal stability of C films. LBL coating gave the C/Z bilayer film an increased elongation and tensile strength, as well as a decreased water vapor and oxygen permeability, especially for C:Z = 1:3 which had better properties. The results suggested that C and Z bilayer films may be a promising material for food packaging with the desired water resistance. [Display omitted] • A bilayer film based on chitosan and zein was fabricated by LBL casting method. • Physicochemical property can be tuned by the zein layer. • The bilayer films showed excellent water resistance and mechanical properties. • The C:Z 1:3 films had better mechanical and barrier properties. [ABSTRACT FROM AUTHOR]

Carboxymethyl starch (CST) was introduced to improve gelatin films and its practical application as edible high-performance films for food packaging and cooking was also investigated. The gelatin films modified by carboxymethyl starch exhibited the transparent appearance, tensile strength, barrier properties (oxygen, water vapor and UV light), and thermal performance (TGA, thermal shrinkage and heat-sealing strength). Resulting from the effect of electrostatic interaction modes on the properties of films, electrostatic repulsion could surpass electrostatic attraction in improving the tensile strength, oxygen barrier property and thermal stability of the films probably due to extensive physical entanglement without aggregation. Analysis of FTIR, zeta potential, interfacial dilatational rheology, shear rheological properties, XRD, Raman, SEM and AFM suggested that hydrogen bonding and electrostatic repulsion contributed to the excellent performance. The packaged food could also be cooked with the prepared film for porridge; and the film slightly influenced the shear rheological properties of porridge and imposed little effect on the odors (Electronic-Nose) of porridge. Hence, the gelatin films modified by carboxymethyl starch could potentially work as the edible inner packaging or the edible quantitative packaging for food, offer convenience for consumers, reduce the packaging waste and avoid an extra burden on environment. • CST improved mechanical and barrier properties (O 2 , moisture and UV light) of films. • CST enhanced the thermal stability, thermal shrinkage and sealing strength of films. • Hydrogen bonds and electrostatic repulsion improved compact matrix and performance. • Excessive CST granules caused the weak interactions and the property deterioration. • The packaged food could cook porridge and slightly affect the rheology and odors. [ABSTRACT FROM AUTHOR]

To overcome the limitations of chitosan (CS) and konjac glucomannan (KGM), the bilayer films of CS and KGM were prepared by layer-by-layer (LBL) casting method, and the effects of different mass ratios (i.e., C5: K0, C4:K1, C3:K2, C1:K1, C2:K3, C1:K4, and C0:K5) on the microstructures and physicochemical properties of bilayer films were examined to evaluate their applicability in food packaging. The results revealed that the bilayer films had uniform microstructures. When compared with pure films, the bilayer films displayed lower swelling degrees and water vapor permeability. However, the tensile tests revealed a reduction in the mechanical properties of the bilayer films, which was nonetheless superior to that of the pure KGM film. In addition, the intermolecular interactions between the CS and KGM layers were observed through FTIR and XRD analyses. Finally, TGA and DSC analyses demonstrated a decrease in the thermal stability of the bilayer films. Our cumulative results verified that CS-KGM bilayer films may be a promising material for use in food packaging and further properties of the bilayer films can be supplemented in the future through layer-by-layer modification and the addition of active ingredients. • There was good material compatibility between CS and KGM, which formed a uniform and dense bilayer structure. • Compared with pure films, the bilayer films displayed lower swelling degrees and water vapor permeability. • Complexed with CS significantly improves the mechanical properties and reduces the water solubility of pure KGM film. • The optimum mass ratio of CS and KGM in the bilayer films is suggested to be 1:1. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) can be used as an effective reinforcement material for biopolymer films intended for food packaging applications. The aim of this study was to improve the mechanical and barrier properties of xylan-alginate films by incorporating CNFs into the xylan-alginate matrix. CNFs was produced from maize stalk waste residues through a combination of chemical and mechanical treatment. The CNFs was incorporated into the xylan-alginate matrix between 1 and 10 wt%. The suitability of the CNFs reinforced composite films for food packaging applications was investigated by testing the mechanical, thermal and optical properties as well as the moisture sorption, solubility and water vapour permeability of the films. The CNFs produced had fibre diameters between 10 and 80 nm and transmission electron microscopy images showed that the CNFs were highly entangled hence forming a web like structure. It was found that the incorporation of CNFs into the xylan-alginate matrix increased the tensile strength and Young's modulus of the films. The incorporation of CNFs improved the WVP of the films but did not show any significant effect on the thermal properties of the films. [ABSTRACT FROM AUTHOR]

Polymer–clay nanocomposite hydrogel films (PCNCHFs) were prepared from caboxymethyl cellulose, polyvinylpyrrolidone, agar and nanosepiolite clay (0, 0.3, 0.5, 0.7, 0.9 and 1.5% reinforcement) by treating thermally in a simple, rapid, and inexpensive route. The PCNCHFs and its 5-fluorouracil (FU)-loaded composites (PCNCHFs@FU) were tested for FU release and characterized by FTIR, XRD, FE-SEM, EDX, DSC, and TGA analyses to investigate their structural, morphological, and thermal properties. The nanosepiolite-loaded polymer composites (PCNCHF1 to PCNCHF5) exhibited higher tensile strength than the pristine polymer hydrogel (PCNCHF0); consequently, the thermal properties (glass- and melting-transition) were improved. The PCNCHFs@FU demonstrated prolonged FU release at pH 7.4 for 32 h. The biocompatibility of PCNCHFs was tested against human skin fibroblast (CCDK) cells. The viability of cells exposed to all PCNCHFs was >95% after 72 h of culture. The live/dead assay show the proliferation of fibroblast cells, confirming the biocompatibility of the hydrogels. The pH-sensitive PCNCHFs@FU release could be suitable for drug release in cancer therapy, and the developed PCNCHFs may also be useful for tissue engineering, food packaging, and other biological applications. [Display omitted] • CMC-based clay hydrogels (PCNCHFs) prepared by moist-heat ensuing solution casting. • PCNCHFs exhibit higher thermal, mechanical, swelling, and FU release properties. • PCNCHF5 showed higher (78 MPa) tensile strength than PCNCHF0 (50 MPa). • PCNCHF5 revealed higher FU release compared to PCNCHF0 at pH 7.4 and 1.2. • The non-toxic behavior of PCNCHFs against CCDK cells confirm their biocompatibility. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop novel micro-nanofibers for food packaging using grapevine extract (GLP) and gelatine using electroblowing technique. The identified components of GLP were dominated by the flavone group phenolics, as analyzed by LC-MS/MS. SBS was used to fabricate gelatine micro-nanofiber mats loaded with three different concentrations of GLP, which were subsequently cross-linked. The micro-nanofibers were characterized by their morphology, chemistry, thermal properties, and bioactivity. The in-vitro antioxidant and antimicrobial effects of the nanofiber mats were determined using various methods, which showed an increase in effectiveness with increasing GLP concentration. The in-situ assessment, where the nanofibers were applied to cheese, also showed a consistent improvement in shelf life with the use of GLP-loaded gelatin electroblown fibers. [Display omitted] • Grapevine leaf extract yielded 24 identifiable components. • Novel food packaging from electroblowing at 10 mL/h feeding rate. • Innovative packaging tested for efficacy against spoilage in cheese. • Electroblowing showcased promise for food packaging applications. [ABSTRACT FROM AUTHOR]

This study investigates the influence of various fillers on the properties of carrageenan, a natural polymer derived from red seaweed. Despite its potential for enhanced biocomposite film development, carrageenan faces challenges related to strength. The incorporation of nanoclay into the carrageenan film resulted in a significant increase in film thickness from 0.026 to 0.068 mm. The UV light transmission value for the carrageenan film alone was measured at 30.9 %, whereas films containing 5 wt% of Tetraethyl orthosilicate (TEOS), 3-Aminopropyltriethoxysilane (APTES), and nanoclay exhibited reduced transmission values of 23 %, 18 %, and 1 %, respectively. Notably, the tensile strength of the unfilled carrageenan film was 38.4 MPa, which increased to 38.6, 57, and 60 MPa upon the addition of 3 wt% of nanoclay, APTES, and TEOS fillers, respectively. All fillers contributed to improved tensile strength, with TEOS demonstrating the highest enhancement. The optimal filler content was determined to be 3 wt%. Regarding thermal properties, films containing TEOS displayed higher thermal stability compared to those with APTES, while films incorporating nanoclay exhibited the lowest stability. Findings provide insights into the effects of different fillers on the mechanical, physical and thermal properties of carrageenan films, supporting the development of improved biocomposite materials suitable for application in food packaging. • Nanoclay, TEOS and APTES were used to modify of the carrageenan film. • Silane-containing films have good interaction with the biopolymer matrix. • Nanoclay-containing films performed excellent in the case of UV transmittance. • Nanoclay-containing films showed better contribution to thermal stability. • Incorporation of the fillers in biopolymers resulted in higher tensile strength. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop novel micro-nanofibers for food packaging using grapevine extract (GLP) and gelatine using electroblowing technique. The identified components of GLP were dominated by the flavone group phenolics, as analyzed by LC-MS/MS. SBS was used to fabricate gelatine micro-nanofiber mats loaded with three different concentrations of GLP, which were subsequently cross-linked. The micro-nanofibers were characterized by their morphology, chemistry, thermal properties, and bioactivity. The in-vitro antioxidant and antimicrobial effects of the nanofiber mats were determined using various methods, which showed an increase in effectiveness with increasing GLP concentration. The in-situ assessment, where the nanofibers were applied to cheese, also showed a consistent improvement in shelf life with the use of GLP-loaded gelatin electroblown fibers. [Display omitted] • Grapevine leaf extract yielded 24 identifiable components. • Novel food packaging from electroblowing at 10 mL/h feeding rate. • Innovative packaging tested for efficacy against spoilage in cheese. • Electroblowing showcased promise for food packaging applications. [ABSTRACT FROM AUTHOR]

Nano-chitosan (NCH), nano-cellulose (NCL) and cellulose derivative are biodegradable biopolymer. Nano-chitosan or nano-cellulose at different concentrations (0.1, 0.5 and 1%) incorporated in carboxymethyl cellulose (CMC) film solution using casting methods. Both CMC/NCH and NCL decreased physical properties (water solubility, moisture content and moisture absorption) especially in concentration of 1%. However, these properties in CMC/NCH were significantly (p < 0.05) lower than CMC/NCL. Water vapor permeability of polymer and nanofiller decreased when nanocomposite concentration increased. Tensile strength and Elongation at break improved in nanocomposite film by increasing concentration. Thermal properties of CMC/NCH were significantly (p < 0.05) lower than CMC/NCL. Emersion of crystalline peaks in X-ray analyses certified the presence of nanofiller in polymer. However, in high content (1%) cause to create aggregation of nanofiller in CMC film. Finally antibacterial activity against five pathogens was studied and good effective inhibition on CMC/NCH was observed while CMC/NCL had no inhibitory effect. These results show that use of CMC/NCH as a biocompatible film has more advantages than CMC/NCL biopolymer. Unlabelled Image • Incorporation of NCH and NCL to CMC improved WVP and mechanical properties of film. • The CMC films with various contents of NCH could inhibit the pathogens tested. • CMC/NCH films had better activities compared to CMC/NCL. • The CMC nanocomposite films have a potential for application in food packaging. [ABSTRACT FROM AUTHOR]

This paper reports a green nanocomposite made by simply blending chitin nanofibers and bamboo cellulose nanofibers without chemically dissolving chitin and cellulose raw materials. Good biodegradability and biocompatibility of chitin in conjunction with good mechanical properties of cellulose are beneficial for developing green nanocomposite applicable for food packaging. The bamboo cellulose nanofiber (BACNF) is isolated by using a TEMPO-oxidation followed by an aqueous counter collision (ACC) method. Chitin nanofiber (CTNF) is isolated by using the ACC method. A simple blending is used to prepare the nanocomposite with different CTNF and BACNF concentration. Morphologies, mechanical properties, chemical interactions, thermal properties, water contact angles and biodegradability of the nanocomposite are investigated. The tensile strength and Young's modulus of the prepared nanocomposite increased up to 3 and 1.3 times, respectively as the BACNF concentration increase. The nanocomposite exhibites better thermal stability than the pure BACNF. Furthermore, the nanocomposite is fully biodegradable within a week. Good mechanical, thermal properties as well as biodegradability of the nanocomposite are promising for possible food packaging application. • A green nanocomposite is made by simply blending chitin nanofibers and bamboo nanofibers without solvent use. • Chitin nanofibers are isolated by using an aqueous counter collision method. • Bamboo nanofibers are isolated by using TEMPO oxidation and the aqueous counter collision. • Mechanical, thermal properties and biodegradability of nanocomposites are improved. • Owing its good biodegradability and mechanical properties, the prepared nanocomposite is beneficial for food packaging. [ABSTRACT FROM AUTHOR]

Nano-bacterial cellulose (BC), as a reinforcing agent, was used to prepare the agar-based edible films. Effects of BC content (0, 3, 5, 8 and 10%, wt% based on the agar) on the rheological properties of film-forming solution (FFS), and on structure, morphology, crystallinity, and thermal properties of films were investigated. Results of rheological and FTIR analyses revealed that interactions between BC and agar were formed through hydrogen bonds. The crystallinity and the thermal stability of films were improved by addition of BC analyzed by XRD and TGA, respectively. Compared with high BC concentrations (8–10%), a good dispersion of BC at low concentrations (3–5%) in the films was observed by SEM. Moreover, BC addition (10%) significantly decreased moisture content (MC), water solubility (WS) and water vapor permeability (WVP) by 60.4%, 13.3% and 25.7%, respectively. The tensile strength (TS) of films increased from 22.10 to 44.51 MPa after addition of BC (0–10%), whereas the elongation at break (EAB) initially increased with increasing BC concentrations (0–5%), and then decreased with further addition of BC (8–10%). Consequently, agar-based edible films reinforced by moderate nano-BC have the potential as a packaging film for food products. [ABSTRACT FROM AUTHOR]

In the food packaging sector many efforts have been (and are) devoted to the development of new materials in order to reply to an urgent market demand for green and eco-sustainable products. Particularly a lot of attention is currently devoted both to the use of compostable and biobased polymers as innovative and promising alternative to the currently used petrochemical derived polymers, and to the re-use of waste materials coming from agriculture and food industry. In this work, multifunctional eco-sustainable systems, based on poly(lactic acid) (PLA) as biopolymeric matrix, diatomaceous earth as reinforcing filler and spent coffee grounds extract as oxygen scavenger, were produced for the first time, in order to provide a simultaneous improvement of mechanical and gas barrier properties. The influence of the diatomite and the spent coffee grounds extract on the microstructural, mechanical and oxygen barrier properties of the produced films was deeply investigated by means of X-Ray diffraction (XRD), infrared spectroscopy (FT-IR, ATR), scanning electron microscopy (SEM), uniaxial tensile tests, O 2 permeabilimetry measurements. An improvement of both mechanical and oxygen barrier properties was recorded for systems characterised by the co-presence of diatomite and coffee grounds extract, suggesting a possible synergic effect of the two additives. [ABSTRACT FROM AUTHOR]