Water Vapor Permeability Research Articles

Development and characterization of sustainable active pectin films: The role of choline chloride/glycerol-based natural deep eutectic solvent and lavender extracts

This study aimed to evaluate the potential effects of choline chloride: glycerol-based natural deep eutectic solvent (NADES) as a plasticizer, NADES extract (NADESext) of lavender as both plasticizer and active ingredient, as well as the lyophilized extract (LE) of lavender at different concentrations (0.5 %, 1 %, and 2 %) on the physical, mechanical, optical, thermal, barrier, morphological, and antioxidant properties of pectin films. The properties of the films were compared to those of the neat pectin film and the film plasticized with glycerol. The addition of plasticizers and LE increased thickness, water vapor permeability, and elongation at break values of the films while decreasing tensile strength and young modulus. Pectin films plasticized with glycerol, NADES, and NADESext had a similar color property but a lower opacity. The use of LE decreased lightness and increased opacity compared to the films with plasticizers. The addition of plasticizers revealed a smoother surface than neat pectin film while LE triggered the formation of agglomerates on the films. Changes in the FTIR spectra of the films showed some interactions between pectin and polyphenols in LE. The plasticizers had an insignificant effect on the antioxidant capacity of films whereas LE improved antioxidant capacity depending on the concentration. In conclusion, the results suggested that pectin films with NADES and LE could be beneficially used to improve antioxidant packaging technology along with acceptable mechanical properties.

Fabrication of antimicrobial and high-toughness poly (lactic acid) composite films using tung oil derivatives

Tung oil derivatives are promising alternatives to traditional toxic plasticizers for improving the toughness of poly (lactic acid) (PLA) films. In this study, a tung oil-based quaternary ammonium salt (Q-ETO) was synthesized using a multi-step process involving epoxidation, ring opening, and substitution reactions. PLA based composite films with various amounts of Q-ETO were prepared by solvent casting. The impact of various amount of Q-ETO on PLA/Q-ETO composite films were evaluated with regard to their mechanical properties, hydrophilicity, water vapor permeability, optical properties, thermal stability, antibacterial properties, and leaching properties. The PLA/5%Q-ETO composite film yielded the highest elongation at break (82.52 ± 9.53 %), which was 153.67 % higher than that of pure PLA. All PLA composite films showed an antibacterial efficiency exceeding 90 % against both S. aureus and E. coli. Moreover, the PLA/Q-ETO composite film blocked the transmission of both ultraviolet and visible light while preventing the permeation of water vapor. The addition of Q-ETO only weakly affected the color and thermal stability of the PLA/Q-ETO composite film. Given the numerous advantages of the PLA composite film, it has significant potential for application as a food packaging material.

Preparation and characterization of potato starch-based composite films reinforced by modified banana fibers and its application in packaging of grapes

The current study focuses on the preparation and characterization of potato starch-based biocomposite films by reinforcing them with banana fiber. The banana fibers were modified using ultrasonication and cellulase enzyme, individually and in combination. Both native and modified banana fibers underwent physical, morphological, FTIR, and crystallinity analyses. The resulting biocomposite films, created by incorporating native and treated banana fibers, were then evaluated for their mechanical, thermal, barrier, and biodegradable properties. The findings indicated that combining ultrasound with enzyme treatment of banana fibers in the potato starch matrix led to a substantial reduction in water-sorption and water-vapor permeability (0.156 g mm m−2 h−1 kPa−1) of the packaging films. Additionally, the mechanical properties (5.02 MPa-Tensile strength, 4.27 MPa-Sealability) of the films significantly improved with the inclusion of modified banana fibers. FTIR analysis revealed similar spectra for all modified samples, along with enhanced crystallinity. Moreover, the thermal stability of the developed films was enhanced by the incorporation of modified banana fibers. Scanning electron microscopy showed that the modified fibers exhibited smooth surfaces and an even distribution of spaces compared with the native fibers. The biocomposite films demonstrated biodegradation within 42 days. Furthermore, the packaging application was tested with grapes, which showed that the films could maintain storability for up to 8 days. Overall, these results suggest a promising eco-friendly method for producing packaging films with biocompatible, biodegradable, and non-toxic properties.

Development of climatic damage predictive tool for timber façade moisture-related damage

Development of the method for automated and adaptive assessment of mould growth in the timber frame facade is presented. A heat, air, and moisture (HAM) transport simulation using the open-source Python library HAMOPY is validated against a well-established software (WUFI Pro 1D). Climate input of the reference year in Norway, Oslo is used in validation. The material parameters of the 1D numerical model that influence mold growth conditions most are identified via a parametric study. The increased water vapor permeability and thermal conductivity of the outside envelope as well as the critical relative humidity threshold are selected as the model updating parameters to account for the risk of the thermal bridge, moisture leakage, and mold growth conditions variation in the model. The example of the automated parametric computation of the mold growth conditions in the facade is presented for a reference climate based on the developed and validated HAM model.

Statistical analysis of textile structures based on conductive yarns

This work presents a series of textile structures fabricated by weaving and knitting using insulating, conductive and antistatic yarns. The physical-mechanical (thickness, water vapour permeability, mass and air permeability), electrical (electrical resistivity), and morphological (SEM, EDAX) properties of the textile structures were analysed to highlight their application potential in interactive products. The statistical analysis of the correlations between physical-mechanical and electric properties was conducted by correlation analysis using the electrical surface resistivity values as dependent variables and the mass (M), thickness (δ) and water vapour permeability (Pv) as independent variable.

Biodegradable active coating from chitosan/astaxanthin crosslinked with genipin to improve water resistance, moisture and oxygen barrier and mechanical properties of Kraft paper

An active chitosan-based coating with an addition of a natural antioxidant and a natural crosslinker has been applied to improve the performance of Kraft paper. Coatings, including chitosan (CS), CS crosslinked with 1.5 % genipin (CS-1.5G), CS containing 1 % astaxanthin (CSA) and CSA crosslinked with 1 % genipin (CSA-1G) were coated on Kraft paper. Uncoated and coated papers were then evaluated for water content (WC), water vapor permeability (WVP), contact angle, oxygen permeability (OP), tensile strength (TS), bursting strength and elongation at break (EAB). Results indicated that the coating improved the properties of Kraft paper. When compared with CS-coated paper, WC and WVP of CSA-1G-coated paper decreased significantly by 40 % and 24 %, respectively. The lowest OP was also observed in CSA-1G-coated paper. CSA- and CSA-1G-coated paper had contact angle values >100°, indicating hydrophobic nature of coated paper surface. All coatings largely improved TS of the paper (by 182–224 %) whereas CS-1.5G and CSA-1G significantly improved the bursting strength of the paper. The developed genipin-crosslinked chitosan-based coating enriched with astaxanthin can improve the functional properties of Kraft paper and thus will facilitate the usage of the paper for food packaging applications.

Active packaging based on tilapia skin gelatin added with lemon basil leaf extract

Active packaging can actively change the condition of the packaged food by optimizing its ability to maintain the product. Edible film is easily digested and has zero waste. Gelatin can form a flexible and strong film. The high amino acids in gelatin can increase its ability to form a gel. Tilapia skin (Oreochromis niloticus) contains high protein. It is a suitable material to be developed into edible films and active packaging by adding lemon basil leaves (Ocimum basilicum L.) as antioxidants and antimicrobials. This study aimed to determine the effect of various concentrations of basil leaf extract on the physical, mechanical, chemical, and antibacterial properties of the gelatin-based edible film of tilapia skin. The treatment used different concentrations of lemon basil leaf extract; 0.2%, 0.4%, 0.6% and 0.8%. The tests include thickness, solubility, tensile strength and elongation, moisture content, water vapor permeability (WVP), antibacterial activity, and antioxidant activity. The results showed that adding lemon basil leaf extract significantly affects the value of solubility, tensile strength, elongation, moisture content, antibacterial activity, and antioxidant activity but was not significantly different on the thickness and WVP parameters.

The Potential of Chitosan-Starch Blend Polymers as Edible Coatings for The Preservation of Fruits and Vegetables: A Mini-Review

Fruits and vegetables are essential for human life. Maintaining the quality and safety of fruits and vegetables are critical challenges for the food packaging industry in this decade. Chitosan and starch are most widely used for food packaging as they bring unique properties for packaging applications. Chitosan has good antimicrobial properties but weak water vapor permeability. Meanwhile, starch has a better water vapor barrier but has poor mechanical properties. This paper discusses the application of chitosan and starch blends in the field of films and coatings. Several characteristics, such as mechanical, thermal, antimicrobial properties, solubility, and water vapor permeability, are also discussed. This review also discussed several applications of chitosan-starch-based films and coatings for the preservation of fruits and vegetables.

CHARACTERIZATION OF CORN STARCH EDIBLE FILMS BY THE ADDITION OF CHITOSAN AS A VEGETABLE OIL PACKAGING MATERIAL

Abstract - Vegetable oil packaging materials use a type of synthetic polymer that is harmful to the body and the environment. Edible film as an environmentally friendly packaging material can be a solution for vegetable oil packaging material. Edible films are made from natural ingredients such as starch and chitosan. The objective of this study is to determine the best conditions of addition of chitosan in making edible film in terms of its physio-chemicals and determine the best glycerol concentration in terms of its physical properties. The composition of raw materials in the form of corn starch is 5 grams and the composition of chitosan is (0,5%, 1% and 1,5% b/v). Glycerol concentrations vary in (4%, 5% and 6% v/v). the result of the analysis of the physical properties of the edible film through the analysis of the physical tensile strength test, namely the best composition on the addition of 1 gr chitosan as well as the elongation analysis at termination. Analysis of the solubility of the edible film at a concentration of 1 gr as well the analysis of water vapor permeability. Whereas the analysis of the best antioxidant capacity in the composition of chitosan is 1,5 gr. Keywords: corn starch, chitosan, edible film

Agro-Industrial Protein Waste and Co-Products Valorization for the Development of Bioplastics: Thermoprocessing and Characterization of Feather Keratin/Gliadin Blends.

Biopolymers based on plant and animal proteins are interesting alternatives in the development of films with future prospects as food packaging. Considering that in recent years there has been an increasing interest in the valorization of agro-industrial residues and by-products and that the blending of polymers can lead to materials with improved properties, in this work, keratin-rich feather fibers and gliadins were blended at different ratios in order to develop sustainable and biodegradable films. Control gliadin G100, feather F100 films, and their blends at 3:1 (G75F25), 2:2 (G50F50), and 1:3 (G25F75) ratios were successfully developed through thermoprocessing. The physical properties were differentiated as a function of the concentration of both polymeric matrices. Although gliadins showed higher hydrophilicity as confirmed by their highest swelling degree, films with high gliadin ratios exhibited lower water vapor permeability values at low and medium relative humidities. On the other hand, the feather fiber-based films displayed the highest Young's modulus values and provided an oxygen barrier to the blends, principally at the highest relative humidity. In conclusion, the blend of these protein-based polymers at different ratio resulted in interesting composites whose physical properties could be adjusted.

Tannic Acid and Ca2+ Double-Crosslinked Alginate Films for Passion Fruit Preservation.

In this study, the interaction of different concentrations of tannic acid (TA) (10%, 20%, and 30% w/w) and Ca2+ with alginate (SA) was utilized to create double-crosslinked SA films. The resulting films were evaluated for their optical, mechanical, water resistance, and barrier properties, and their microstructure and intermolecular interactions were also characterized. The SA films containing 20% TA showed the best mechanical properties, with an observed increase in tensile strength of 22.54%. In terms of water vapor permeability, the SA film containing 30% TA exhibited the highest barrier property, which was 25.36% higher than that of the pure SA film. Moreover, TA demonstrated a strong UV absorption ability, resulting in a nearly 0% UV transmittance of the SA film at 280 nm. It can be seen that SA films containing 20% TA have excellent barrier and mechanical properties, and the development of such films will be applied to the storage and packaging of fresh food. It is worth noting that this work also investigated the effect of SA coatings containing different concentrations of TA on the preservation of passion fruits for 7 days. The results revealed that passion fruits treated with SA coatings containing a 30% TA concentration maintained a better appearance on the 7th day and had the lowest weight loss and crumpling indices of approximately 8.98% and 2.17, respectively, compared to the other treatment groups. Therefore, based on the overall results, the addition of 30% TA to SA coatings proved to be more effective and can be considered a promising approach for delaying fruit senescence and decay.

Chitosan-based edible film incorporated with wampee (Clausena lansium) seed essential oil: Preparation, characterization and biological activities

Chitosan (Ch)-based edible composite films were prepared by incorporating blending wampee seed essential oil (WSEO) into a Ch matrix, using the incorporation ratio as a variable. The physical, mechanical properties, structure morphology and rheological properties were determined using tensile strength (TS), elongation at break (EB), water vapor permeability (WVP) tests together with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) observations and apparent viscosity and shear rate. In addition, the antimicrobial, antioxidant activities were investigated by the DPPH & ABTS radicals scavenging and inhibition zone assays, respectively. Compared with Ch, the incorporation of WSEO significantly decreased (P < 0.05) the TS, EB, and WVP values, especially when the WSEO ratio reached 1.0 % or higher. Meanwhile, the films exhibited greatly improved visible light barrier performance after WSEO incorporation. Both FTIR spectroscopy and SEM observations reflected the crosslinking between WSEO and Ch. Meanwhile, the composite films demonstrated smaller particle size and weaker rheological viscosities, which enhanced the antimicrobial and antioxidant capabilities when compared with those of Ch. Therefore, this study suggested that WSEO incorporated with Ch is an effective ingredient for the preparation of edible films with enhanced physicochemical and biological properties.

Effect of ε-Polylysine Addition on Pullulan Biodegradable Films for Blueberry Surface Coating

A biodegradable film was successfully prepared using pullulan and ε-polylysine (ε-PL). The impact of ε-PL contents on biodegradable film was explored through mechanical properties, water vapor permeability, and an FTIR spectroscopy test. Amongst all the prepared films, the 0.5% ε-PL had the most desirable results in film performance. The TS, EAB, and WVP values were 5.63 MPa, 21.5%, and 0.27 × 10−6 g m/Pa h m2, respectively. The blueberries coated with 0.5% ε-PL and pullulan were stored at 20 °C for 12 days. The effect of edible coatings on the performance of blueberries was evaluated by detecting the physicochemical properties and the contents of antioxidants. The experimental results displayed that ε-PL and a pullulan blend film could decrease the weight loss and maintain the hardness, polyphenol, anthocyanin, and antioxidant capacity of the blueberry preservation. The results indicated that the biodegradable film is a potential fruit-coating material.

Nanocomposites of soluble soybean polysaccharides with grape skin anthocyanins and graphene oxide as an efficient halochromic smart packaging

In this study, an environmentally-friendly pH-responsive (halochromic) film was introduced based on the composite of soluble soybean polysaccharide (SP), grape skin anthocyanin extract (GE) and graphene oxide (GO) to monitor food freshness/spoilage in terms of smart packaging. GO was firstly synthesized and characterized; then, SP-based film containing 5 wt% GE and the optimum amount of GO (0.5 wt%) was fabricated through the solvent casting method and characterized in terms of physico-mechanical, thermal, microstructural, spectroscopic, release, pH sensitivity and colorimetric properties. Our results revealed that addition of GE into the SP matrix induced pH sensitivity to the film; however, it decreased the mechanical and thermal properties, and increased moisture content (MC) and water vapor permeability (WVP) of the film. The incorporation of GO into the film eliminated the GE-caused weaknesses and improved the mechanical and thermal properties, and also decreased the MC and WVP of the film. Moreover, the SP-GE-GO nanocomposite film represented a distinguishable color variation in response to TVB-N release and pH changes when used as the salmon fish packaging. Generally, the obtained results indicated that the SP-GE-GO film can be considered a promising candidate for halochromic smart food packaging.

POTENTIAL USE OF AN EDIBLE CANDELILLA WAX-BASED COATING TO EXTEND THE SHELF LIFE OF PASSION FRUIT

Passion fruit (Passiflora edulis f. flavicarpa Degener) is not widely traded due to its short shelf life. Edible coatings can be used to extend the postharvest life of fruits. The objective of this study was to develop a candelilla wax-based coating (Euphorbia antisyphilitica Zucc) for the preservation of passion fruit. Three coating formulations (C1, C2, and C3) were made with pectin, glycerol, and candelilla wax and applied by immersion. Weight loss and changes in physical appearance were used to assess shelf life under two storage conditions: room temperature (32 °C/6 days) and refrigeration (6.6 °C/32 days). Uncoated fruit in both storage conditions served as controls. Furthermore, a physicochemical characterization of the coatings was performed. Coated fruit at room temperature showed an improvement in weight retention compared to controls, but no differences in physical appearance were observed. In fruits stored under refrigeration, only C2 had less weight loss compared to the control, while C3 maintained a better physical appearance. In terms of coating characterization, C3 presented the lowest moisture content and thickness. C1 obtained the highest density value, while C1 also had the highest water vapor permeability rate (TPVA) value. The application of the C2 coating was effective in preserving the fruit for a longer period of time, and this coating has the lowest TPVA value, which is related to the decrease in weight loss in the fruit.

Impact of calcium addition on the characteristics of hyaluronic acid-based oral films for vitamin D supplementation

An orally disintegrating film (ODF) was developed using hyaluronic acid as a base material, along with incorporation of vitamin D and varying amounts of calcium citrate. Increasing calcium amount within ODF resulted in higher opacity of the film, and stiffer texture. Microscopic examination of calcium-added films revealed consistently rough surfaces and cross-sections with irregular roughness. The moisture content and water vapor permeability were found to be higher in calcium-added films than in control films, however there was no significance by calcium amount. The content analysis indicated a loss of 32.66–46.16% of vitamin D and 8.05–13.53% of calcium in a sheet of ODF, which could be attributed to the formation of new chemical bonds among HA, vitamin D and calcium based on the result of FT-IR. In this study, it was successfully developed an ODF containing both vitamin D and calcium. However, unlike vitamin D, which can be added in recommended quantities within a single ODF, the addition of the insoluble bulk mineral, calcium, is limited, indicating that addition of plasticizer or technologies may be required to achieve an adequate amount of calcium incorporation into the ODF.

A graphene-enhanced high-barrier and fast-curing film for deep in situ condition preserved coring in coal seams

Scientific research on deep in situ resources is highly important to the theory and technology system construction for deep in-situ resource exploitation. To obtain high-condition preserved core samples, it is vital to maintain the original material, humidity and luminous flux information inside the core. Therefore, this study proposes a research and development strategy for a high-toughness and high-barrier sealing film based on the molecular structure design and filler synergistic enhancement via a deep solid-state sealing film using in situ substance preservation (ISP), in situ moisture preservation (IMP) and in situ light preservation (ILP) coring principles. A graphene/epoxy composite sealing film with a high barrier, high strength and high toughness was developed. The oxygen permeability of the film was 0.23 cm3/(m2·d), the water vapor permeability was 1.26 g/(m2·d), and the light transmittance was 0. The tensile strength reached 15.4 MPa, and the toughness was 5242.9 kJ/m3. The results from the film substance and moisture preservation performance verification experiments showed that the sealing film had an excellent sealing effect on small molecules, such as water, alkanes and even ions, which further verified that the sealing film greatly contributed to the maintenance and preservation of deep in-situ resource reserves and abundance.

Carboxymethyl cellulose based films enriched with polysaccharides from mulberry leaves (Morus alba L.) as new biodegradable packaging material

The objective of this study was to determine the properties of a new active packaging film developed by the addition of mulberry leaves polysaccharides (MLP) into carboxymethyl cellulose (CMC). Biodegradable CMC-MLP films were fabricated by casting method with various concentrations of MLP (1, 5 and 10 % w/w). The addition of MLP into the CMC matrix resulted increased thickness (0.126 to 0.163 mm) and roughness of the films. Also, the decline in moisture content from 27.91 to 14.12 %, water vapor permeability from 8.95 to 5.21 × 10−10 g−1 s−1 Pa−1, and a swelling degree from 59.11 to 37.45 % were observed. With the increasing concentration of MLP, the mechanical properties of the films were improved and higher dispersion of UV light were noted. Fourier transform - infrared spectroscopy (FT-IR) and X-ray diffraction revealed good inter-molecular interaction between CMC matrix and MLP. The prepared films showed excellent thermal stability, antioxidant and antibacterial properties as well as susceptibility to biodegradation in the soil environment. Moreover, it was proved that the films have ability to retard oil oxidation. Overall, it was concluded that CMC-MLP films constitute a promising biomaterial that may be applied as active food packaging.

Development and characterization of new formulation of biodegradable emulsified film based on polysaccharides blend and microcrystalline wax

Abstract The aim of the present work is the development and characterization of new formulation of emulsified films based on soluble starch/sodium alginate blend and microcrystalline wax. The developed films were studied in order to use them as new formulations to produce food packaging. The obtained films were generally homogeneous, thin, and slightly flexible. These films appeared more opaque compared to the non-emulsified film. Incorporation of microcrystalline wax was caused modifications of mechanical properties of films; these modifications were principally due to the formation of amylose–lipid complex. It was found that microcrystalline significantly reduced film water vapor permeability (WVP) of emulsified films. Atomic force microscope (AFM) was used to evaluate surface topography and roughness of the films. The surface topography was significantly affected, in the other word high roughness values were obtained. Microemultion formation in which the microcrystalline wax particles are distributed homogeneously within the polymer matrix was investigated by scanning electron microscopy (SEM). Moreover, the polysaccharides blend/microcrystalline wax emulsified films can be useful as a biodegradable packaging material to maintain the quality of food products.

Study of the Physical, Chemical, and Structural Properties of Low- and High-Methoxyl Pectin-Based Film Matrices Including Sunflower Waxes.

The development of bio-based materials remains one of the most important alternatives to plastic materials. Although research in this field is growing, reporting various materials and methodologies, it is still necessary to increase exploration. The aim of this work was to expand and complement previous research on the preparation and characterization of high- and low-methoxyl pectin films obtained by casting, with the addition of commercial and recovered sunflower waxes. The results showed that the addition of sunflower waxes to the pectin matrix generated some discontinuity in the aggregate, increasing the thickness and roughness of the film. However, due to their hydrophobic nature, the waxes contributed to lower vapor transmission rate values of the films. On the other hand, the low-methoxyl pectin films had a more crystalline structure, which could help to diminish water vapor permeability values, mechanical resistance and rigidity, and improve their elongation. Regarding chemical characteristics, most of the raw materials' chemical groups were found in the resulting films, and the presence of C-H bending due to pectin gelation was observed. Finally, the compatibility and contribution of pectin and sunflower waxes to the production of the films were demonstrated, as well as the possibility of using materials from industrial waste in food packaging applications.