Lower Water Vapor Permeability Research Articles

Development of Pectin and Poly(vinyl alcohol)-Based Active Packaging Enriched with Itaconic Acid and Apple Pomace-Derived Antioxidants.

The production of active and biodegradable packaging materials is an emerging and efficient alternative to plastic packaging materials. By combining poly(vinyl alcohol) (PVA), pectin, and itaconic acid (IA), biodegradable and water-soluble packaging materials can be obtained that can also increase the shelf-life and quality of foodstuff. In the present study, the generated film-forming solutions were enriched with organic or phenolic extracts from apple by-products (apple pomace). These extracts possess an efficient antioxidant activity of 9.70 ± 0.08, and 78.61 ± 0.24 μM Trolox/100 g fresh weight, respectively. Furthermore, the lyophilization of these by-products increased the extract’s organic and phenolic content and the antioxidant activity to 67.45 ± 0.28 and 166.69 ± 0.47 μM Trolox/100 g fresh weight, respectively. These extracts influence the physical-chemical properties of the biofilm solutions by facilitating the polymerization process and thus positively influencing their viscosity. The resulting biofilms presented low water vapor permeability and reduced solubility in water. Adding IA and organic/phenolic compounds facilitates the resistance against intrinsic and extrinsic factors; therefore, they might be applicable in the food industry.

Designing antimicrobial polypropylene films with grape pomace extract for food packaging

Grape pomace (mixture of skins and seeds) is a residual by-product of the winemaking process, rich in polyphenolic compounds that have antioxidant and antimicrobial properties and can be recycled to manufacture fruit extracts to be used in new technological products. The use of non-toxic substances is exciting for developing packagings that are in direct contact with food, as components present in the polymer might migrate to the food. Moreover, the gradual release of these non-toxic bioactive components confers long-term antimicrobial activity to these PP films enriched with grape pomace extract. In addition, the use of raw materials from natural and renewable origins to manufacture antimicrobial packaging contributes to a more sustainable and eco-friendly industrial production and to mitigate environmental impacts. In this research, bactericidal isotactic polypropylene (PP) was developed using grape pomace extract as an antimicrobial additive and presents low water vapor permeability and antimicrobial activity against Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria, showing potential to function as an active and safer polymeric food packaging.

Characterization of a new food packaging material based on fish by-product proteins and passion fruit pectin

The development of biodegradable bioplastics based on renewable raw materials has emerged as an innovative option to minimize the adverse effects of improper disposal of petrochemical packaging in the environment. This study aimed to optimize the conditions for bioplastic production from proteins of the cutting by-product of Serra Spanish Mackerel (Scomberomorus brasiliensis) and pectin of the yellow passion fruit (Passiflora edulis Flavicarpa), evaluating the physical, mechanical and thermal characteristics of the optimized bioplastic. According to the results, the optimal conditions for obtaining the bioplastic were 5.0% protein concentrate and 3.0% pectin. The optimized film was homogeneous, strong, flexible, and biodegradable, with low solubility and water vapor permeability, indicating that the protein and pectin biopolymers had good interaction and could produce bioplastics. Therefore, there was a satisfactory interaction between the incorporated biopolymers, indicating their application in the food industry and thus causing a reduction in the production of industrial by-products.

Parameters Affecting the Water Vapour Permeability of Gelatin Films as Evaluated by the Infrared Detecting Method ASTM F1249

The purpose of this study was to assess testing parameters for measurement of water vapour permeability (WVP) properties of bovine gelatin films by ASTM F1249. This method utilises an infrared sensor to determine the WVP of conventional plastic-based films and has been widely applied within the packaging industry, but has had very limited application with hydrophilic compostable/edible packaging materials. These films have low WVP properties with highly variable WVP values (as studied by ASTM E96); consequently, this parameter has to be carefully controlled. Assessment of the module was carried out using bovine gelatin films with different thicknesses of film, and gelatin was chosen as an example of such film types using the following Mocon Permatran testing parameters: 50 or 70% relative humidity (RH), 100 or 150 cm3 nitrogen gas flow rates for the module’s RH-cell (100 cm3 for all other cells). In all cases, WVP increased with an increase in gas flow rate. This method showed that WVP increased with increasing gelatin film thickness, and categorically supports previous—and often unexplained—WVP findings for other hydrophilic, biopolymer films. The current study is a helpful guide to the examination of water barrier properties of hydrophilic edible/biodegradable/compostable packaging materials in research and industry.

Selective Edge Rounding of Cyclic Olefin Copolymer Film Using UV Laser for Implantable Electrode Package.

Cyclic Olefin Copolymer is emerging as a packaging material for implantable electrodes due to its physical properties such as low water absorption rate and low water vapor permeability. The electrode-tissue interface is often regarded as a major focus of implantable electrodes, but its packaging should also be considered thoroughly since it directly contacts the adjoining body cells. Therefore, eliminating any sharp boundaries or edges around the package would be beneficial to minimize potential inflammatory responses caused by physical/mechanical stresses. To smooth both inner/outer edges of a cyclic olefin copolymer packaging, an optimal UV laser condition was investigated by varying its marking speed and iterations. Clinical relevance - This establishes a method that can selectively smooth the edges around a cyclic olefin copolymer pack-aged implantable electrodes for reduced mechanical mismatch after insertion.

Properties and characteristics of salmon frame protein isolate films influenced by glycerol and squalene

Characteristics of edible/biodegradable film based on salmon frame protein isolate (SFPI), a processing by-product, containing glycerol at two different concentrations (50 and 65% by weight of protein) with and without 30% squalene (by weight of protein) were investigated. Without squalene, the SFPI film generally had higher hydrophilicity when higher concentration of glycerol was used as indicated by higher (p < 0.05) water-vapour permeability (WVP). The addition of squalene augmented yellowness and hydrophobicity of SFPI film as indicated by higher b* colour coordinate and lower WVP (p < 0.05), respectively, in comparison to those without squalene. The squalene also promoted the interactions in SFPI film matrix as revealed by Fourier-transform infrared spectra. These interactions were related to a superior mechanical properties, high barrier properties, and increased thermal resistance of the resulting SFPI film. Therefore, the addition of 30% squalene along with 50% glycerol as plasticiser improved physicochemical, mechanical, barrier, and thermal properties of SFPI film, which could be used as an alternative film for edible/biodegradable food packaging.

Utilization of peel of white pomelo for the development of pectin based biodegradable composite films blended with casein and egg albumen

Biodegradable composite films were developed using casting method from white pomelo peel pectin, casein and egg albumin at different proportions. The pectin was incorporated to modify the properties of films and the effect of pectin incorporation on various properties of films was investigated. In comparison to other edible films, the composite films prepared from white pomelo peel pectin, casein protein and egg albumin protein at a ratio of 50:50:0 (F4) and 50:25:25 (F7) possessed highest tensile strength and lowest water vapour permeability. The X-Ray diffraction (XRD) analysis of composite films indicated that the major portion of the film was amorphous. Fourier Transform Infrared Spectroscopy (FTIR) analysis of composite films indicated the increase in the intermolecular interactions of polymers resulting in increase in compactness of film matrix. The curves obtained by Differential Scanning Calorimetry (DSC) indicated that addition of pectin into casein and egg albumin increased the melting temperature and the peak temperature, indicating increased thermal stability of composite films.

In Situ Formation of Microfibrillar PBAT in PGA Films: An Effective Way to Robust Barrier and Mechanical Properties for Fully Biodegradable Packaging Films.

Poly(glycolic acid) (PGA) is a semicrystalline biodegradable polyester with high gas barrier properties. However, due to its poor processability and low ductility, PGA could hardly find applications in the packaging field. Here, a strategy was adopted for in situ generation of high-aspect-ratio flexible microfibrils with strong interface affinity for the PGA matrix. Because poly(butylene adipate-co-terephthalate) (PBAT) possesses impressive ductility, it was selected as the “fibrillar toughening phase” to enhance the ductility of PGA. Moreover, a chain extender was used to enhance the interfacial adhesion between the two polymers. The extrusion blown film technique was then used to develop fully biodegradable PGA/PBAT films with a superior combination of excellent barrier performance and robust mechanical properties. The PBAT phase can in situ form microfibrils under the influence of extensional flow. Simultaneously, the synergetic function of the extensional flow field could effectively promote the motion of the PGA molecular chain to develop an oriented crystalline microstructure. Because of the aligned oriented lamellar crystal of PGA and oriented PBAT fibril structures serving as robust “barrier walls” 60PGA/ADR blown films demonstrated dramatically improved resistance to oxygen and water vapor, with 59 and 44 times lower oxygen permeability and water vapor permeability, respectively, when compared to the neat PBAT blown film. As a result, PGA/PBAT blown films offer a variety of benefits, including superior ductility, toughness, and a strong gas barrier property. The potential of these films to degrade makes them a viable contender for replacing classical nondegradable packing films.

Antimicrobial, antioxidant, and pH-sensitive polyvinyl alcohol/chitosan-based composite films with aronia extract, cellulose nanocrystals, and grapefruit seed extract

Aronia or black chokeberry (Aronia melanocarpa), cellulose nanocrystals (CNCs), and grapefruit seed extract (GSE) were used for the preparation of multifunctional polyvinyl alcohol/chitosan (PVA/CS) composite films with pH-sensitivity, antimicrobial, antioxidant, and UV-barrier properties. Aronia extract showed total phenolic content of 297 ± 0.5 μg GAE/mg aronia extract, potent antioxidant activity, and high color-response efficiency. Isolated CNCs showed a needle-like structure with a length of 470 nm and a width of 35 nm. The tensile strength of the PVA/CS composite film increased by 74% after the incorporation of CNCs, whereas the film flexibility was enhanced by 75% after adding GSE. The PVA/CS-A (aronia extract) composite film showed a significant color change at different pHs and potent antioxidant activity. At the same time, the PVA/CS-G (GSE) showed the highest antimicrobial activity against Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive) bacteria. The PVA/CS-CGA composite film, reinforced with CNCs/GSE/Aronia extract, showed the highest UV-barrier (95.5%), highest antioxidant activity (95%), potent antimicrobial activity, pH-sensitivity, lowest water vapor permeability (WVP), and desirable mechanical properties. The multifunctional properties of the produced composite films encourage their use as active and intelligent food packaging films to extend shelf life and monitor food quality.

Plasticizing effect of Apis mellifera honey on whey protein isolate films.

The aims of this study were to analyze the plasticizing effect of Apis mellifera honey on the mechanical, physicochemical and optical properties of whey protein isolate (WPI) films and to compare the results collected with the plasticizing effect of glycerol on WPI-films. Response surface was applied to optimize the amounts of WPI and glycerol in order to obtain films with higher tensile strength (TS), moderate elongation, and lower water vapor permeability so that they could be used as reference films. Honey was added at different concentrations (60%, 80%, and 100%) of g honey/100 g WPI, as a plasticizer to the WPI-films. In comparison to glycerol-plasticized films, an increase in the percentage of honey produced a reduction of 20 ± 10 to 48 ± 0.5% of TS, a 66± 0.5% lower in Young's modulus (WPI-films with 100% honey), and an increase of 186± 11% in elongation at break in the WPI-films with 100% honey. Honey-plasticized WPI-films were from 29± 11 to 43± 3% less permeable to water vapor than glycerol-plasticized WPI films. The mechanical characteristics of the 80% honey formulation did not differ significantly from those of the reference film (p > 0.05). Findings from this study indicate that honey has great potential as a plasticizer in WPI-films.

Zein Microparticles and Nanoparticles as Drug Delivery Systems.

Zein is a natural, biocompatible, and biodegradable polymer widely used in the pharmaceutical, biomedical, and packaging fields because of its low water vapor permeability, antibacterial activity, and hydrophobicity. It is a vegetal protein extracted from renewable resources (it is the major storage protein from corn). There has been growing attention to producing zein-based drug delivery systems in the recent years. Being a hydrophobic biopolymer, it is used in the controlled and targeted delivery of active principles. This review examines the present-day landscape of zein-based microparticles and nanoparticles, focusing on the different techniques used to obtain particles, the optimization of process parameters, advantages, disadvantages, and final applications.

Effect of active gelatin-starch film containing Syzygium cumini and Origanum vulgare extract on the preservation of lamb burgers

The objective of the research was to control the oxidative stability of lamb burgers by applying gelatin-starch active film containing java plum (Syzygium cumini) and oregano (Origanum vulgare). The films were prepared from four formulations: without extract addition (FC), with the addition of java plum extract (FJ), with the addition of oregano extract (FO) and with the addition of java plum and oregano extract (FJO). Films were characterized in terms of the physical, barrier, mechanical and antioxidant properties. The burgers were analyzed for 90 days by the physicochemical variables, lipid oxidation, and fatty acid profile. The addition of extracts in the films did not affect the tensile strength but showed low water vapor permeability. Antioxidant films with oregano extract and the blend of plant extracts were significantly more efficient than the film with java plum extract. Therefore, the active film resulted in enhanced oxidative stability of lamb burgers and may be used as primary packaging for foods.

Development of biodegradable films using sunflower protein isolates and bacterial nanocellulose as innovative food packaging materials for fresh fruit preservation

This study presents the valorization of side streams from the sunflower-based biodiesel industry for the production of bio-based and biodegradable food packaging following circular economy principles. Bacterial cellulose (BC) was produced via fermentation in 6 L static tray bioreactors using nutrient-rich supplements derived from the enzymatic hydrolysis of sunflower meal (SFM) combined with crude glycerol as carbon source. Novel biofilms were produced using either matrices of protein isolates extracted from sunflower meal (SFMPI) alone or SFMPI matrices reinforced with nanocellulose biofillers of commercial or bacterial origin. Acid hydrolysis was employed for ex-situ modification of BC to nanostructures (56 nm). The biofilms reinforced with bacterial nanocellulose structures (SFMPI-BNC) showed 64.5% higher tensile strength, 75.5% higher Young’s modulus, 131.5% higher elongation at break, 32.5% lower water solubility and 14.1% lower water vapor permeability than the biofilms produced only with SFMPI. The biofilms were evaluated on fresh strawberries packaging showing that the SFMPI-BNC-based films lead to effective preservation at 10 °C considering microbial growth and physicochemical profile (weight loss, chemical characterization, color, firmness and respiration activity). The SFMPI-BNC-based films could be applied in fresh fruit packaging applications.

Silk fibroin-based films in food packaging applications: A review.

Plastic pollution is a significant concern nowadays due to wastes generated from non-biodegradable and non-renewable synthetic materials. In particular, most plastic food packaging material ends up in landfills, creating mass wastes that clog the drainage system and pollute the ocean. Thus, studies on various biopolymers have been promoted to replace synthetic polymers in food packaging and consequently, the high number of research in biopolymers food packaging, especially in the characterization, properties and also the development of the biopolymer. For biopolymer-based food packaging, silk fibroin (SF) has been highlighted because of its biodegradability and low water vapor permeability properties. This review focuses on the different properties of SF films prepared through solution casting and electrospinning for food packaging. Discussions encompassed chemical properties, mechanical properties, permeability, and biodegradability. This review also discussed the studies that used SF as the biomaterial for food packaging.

A Film of Chitosan Blended with Ginseng Residue Polysaccharides as an Antioxidant Packaging for Prolonging the Shelf Life of Fresh-Cut Melon

Ginseng residue polysaccharides (GRP) at three levels were excellently blended into chitosan to form antioxidant composite films, which exhibited higher density, opacity and moisture, as well as lower water vapor permeability, tensile strength and elongation ratio than those of neat chitosan film. Thermogravimetry evidenced no difference in stability, and SEM and AFM revealed smooth and dense surfaces with no cracks and micropores, whereas structural analyses disclosed slight changes in films’ structures after adding GRP. A chitosan film containing 0.5% GRP (Chitosan + GRP) was then employed for a fruit preservation study. Fresh-cut melon covered with Chitosan + GRP displayed delayed deteriorating compared with other groups. A possible antioxidant mechanism in fruit preservation was then suggested, and PCA and correlation analyses supported these findings. The results demonstrated that our antioxidant chitosan films incorporated with GRP are quite promising for enabling the food industry to produce eco-friendly and sustainable packaging.

Edible multilayer coating using electrostatic layer‐by‐layer deposition of chitosan and pectin enhances shelf life of fresh strawberries

SummaryThis study aimed to develop an edible multilayer coating by electrostatic layer‐by‐layer deposition (LbL) of chitosan‐pectin biopolymers to extend the shelf life of strawberries. A fixed concentration of chitosan (2% w/v) and varying pectin concentrations (0.25–1% w/v) in an LbL sequence were initially applied to coat on the low‐density polyethylene (LDPE) film. The successful assembly of these biopolymers in the LDPE film was confirmed by their zeta potential (chitosan, +43 mV and pectin, −36 to −42 mV) and Fourier transform infrared (FTIR) spectroscopy in the range of 1800–1600 cm‐1 indicating the strong interactions between chitosan and pectin. Chitosan (2% w/v) and pectin (0.25% w/v) had the lowest water vapour permeability (WVP) of 1.86 ± 0.02 × 10−9 in gday‐1 m‐1 Pa‐1 among all other formulations. The application of the coating on strawberries extended the shelf life (9 days) compared to the control (6 days) at room temperature (25 °C) while still retaining the colour, firmness and pH of strawberries. The results obtained illuminate the potential application of safer, ecofriendly and sustainable packaging materials in the food industry.

Performance of eugenol emulsion/chitosan edible coating and application in fresh meat preservation

A green chitosan-based coating was prepared by incorporating chitosan-stabilized eugenol emulsions into chitosan solution. The physical, mechanical, rheological, and stability property of chitosan coatings were characterized and then the effect of chitosan coatings on the shelf-life of fresh meat was investigated. Emulsion incorporation greatly improved the performance of chitosan coating, including stronger anti-corrosion against pH and UV-light resistance and lower water vapor permeability. Emulsion incorporation greatly increased the inhibition zone for Escherichia coli and Staphylococcus aureus by 6.9 and 8.7 mm, respectively. After the application of coating, meat kept a bright red appearance within 14 days and its spoilage was prevented. After 14-day storage, pH value, the total number of colonies, and TVB-N of meat still met the quality standard, demonstrating that the shelf-life of meat was prolonged from 6 to 14 days. The knowledge provides a green coating to extend the shelf-life of fresh meat. Novelty impact statement Chitosan-stabilized emulsions were added into chitosan-coating materials. Eugenol-loaded chitosan coating had a good protection effect on the color of meat. Shelf-life of fresh meat was prolonged to 14 days by eugenol/chitosan coating.

Effect of Plasticizer Content on Mechanical and Water Vapor Permeability of Maize Starch/PVOH/Chitosan Composite Films.

Packaging materials based on biodegradable polymers are a viable alternative to replace conventional plastic packaging from fossil origin. The type of plasticizer used in these materials affects their functionality and performance. The effect of different plasticizers such as glycerol (GLY), sorbitol (SOR), and poly(ethylene glycol) (PEG) in concentrations of 5%, 10%, and 15% (w/w) on the structural features and functional properties of starch/PVOH/chitosan films was evaluated. The incorporation of a plasticizer increased the thickness of the biodegradable composite films. Furthermore, the material plasticized with 30% (w/w) sorbitol had the highest elongation at break, lowest water vapor permeability, and better thermal resistance. The results obtained in this study suggest that maize starch/PVOH/chitosan biodegradable composite films are a promising packaging material, and that sorbitol is the most suitable plasticizer for this formulation.

Optimization of the Physical, Optical and Mechanical Properties of Composite Edible Films of Gelatin, Whey Protein and Chitosan.

The aim of this work was to evaluate the effect of the concentration of gelatin (G) (3–6 g), whey protein (W) (2.5–7.5 g) and chitosan (C) (0.5–2.5 g) on the physical, optical and mechanical properties of composite edible films (CEFs) using the response surface methodology (RSM), as well as optimizing the formulation for the packaging of foods. The results of the study were evaluated via first- and second-order multiple regression analysis to obtain the determination coefficient values with a good fit (R ˃ 0.90) for each of the response variables, except for the values of solubility and b*. The individual linear effect of the independent variables (the concentrations of gelatin, whey protein and chitosan) significantly affected (p ≤ 0.05) the water vapor permeability (WVP), strength and solubility of the edible films. The WVP of the edible films varied from 0.90 to 1.62 × 10−11 g.m/Pa.s.m2, the resistance to traction varied from 0.47 MPa to 3.03 MPa and the solubility varied from 51.06% to 87%. The optimized values indicated that the CEF prepared with a quantity of 4 g, 5 g and 3 g of gelatin, whey protein and chitosan, respectively, provided the CEF with a smooth, continuous and transparent surface, with L values that resulted in a light-yellow hue, a lower WVP, a maximum strength (resistance to traction) and a lower solubility. The results revealed that the optimized formulation of the CEF of G–W–C allowed a good validation of the prediction model and could be applied, in an effective manner, to the food packaging industry, which could help in mitigating the environmental issues associated with synthetic packaging materials.

Double-layer indicator films aided by BP-ANN-enabled freshness detection on packaged meat products

Anthocyanins can be used as a pH-sensitive material to indicate freshness of packaged meat products, which can nevertheless be easily degraded, the pigments should be encapsulated in an appropriate matrix. In this study, raspberry anthocyanins were proposed as a novel freshness indicator and were incorporated into low-acyl gellan to improve its stability. Chitosan was used to form an outer layer of a double-layer indicator film. The results showed that the anthocyanin had response to the change of pH value, the double-layer indicator film had strong mechanical properties, low water vapor permeability and good structural compatibility, and the stability of raspberry anthocyanin was improved. To explore the applicability of the developed film system, pork patties and fish balls were selected as test meat products. Back propagation artificial neural network model was established using color of the films as the input and total volatile nitrogen (TVB-N) content as the output. TVB-N contents of pork patties and fish balls increased to spoilage levels after 6- and 3-day storage at 4 ℃; color of the films changed from pink to brown and finally to dark green as storage proceeded. Neural network model well predicted the freshness of packaged meat products based on color change of the films, with R2 of 0.94–0.98.