Lowest Water Vapor Permeability Values Research Articles

A novel biodegradable film based on chicken gelatin and κ-carrageenan cross-linked with oxidized phenolic compounds.

Natural and renewable polymers are gradually replacing petroleum-based plastics, mostly as a result of environmental concerns. Moreover, upcycling industrial food waste into new added-value products is a creative approach that is crucial for cleaner and more sustainable manufacturing. The aim of this study was to obtain an environmentally friendly biodegradable film using a combination of k-carrageenan (KCAR) and chicken gelatin (CGEL), which obtained from poultry by-products. The effects of varying concentrations of KCAR (0-2%) on the physical, permeability, textural, thermal, and microstructural properties of CGEL/KCAR composite films were evaluated. The findings demonstrated that an increase in KCAR enhanced the lightness and opacity levels of the films. Water vapor permeability (WVP) values reduced as the KCAR concentration increased. The lowest WVP value (0.0012g.mm/h.m2.kpa) was seen in the treatment with 2% KCAR. Tensile strength (TS) values increased with increasing KCAR. The films' thermal stability was increased by the addition of KCAR. Microstructure assessments revealed a more compact and smooth structure in the KCAR-containing treatments, indicating improvements in WVP, thermal stability, and TS. Compared to the commercial cattle gelatin film, the CGEL film had higher TS and lower water solubility (WS). Overall, this study showed that the physical, mechanical, barrier and thermal and microstructural qualities of gelatin-based films may be enhanced by combining CGEL and KCAR to create an effective biodegradable film. Moreover, the comparison study between commercial cattle and chicken gelatin films revealed that cross-linked chicken gelatin films would be a suitable alternative for bovine gelatin films in the production of biodegradable film.

Starch-based environment friendly, edible and antimicrobial films reinforced with medicinal plants.

In the current study, cornstarch-based antimicrobial and edible films were designed using solution-casting methods. The medicinal plants (Acontium heterophyllum, Artemisia annua, and Thymus serpyllum) reinforced the gelatinized solution in different concentrations as fillers. The effect of plant extracts on antimicrobial and antioxidant potential, microstructure, barrier, thermal and mechanical properties of cornstarch-based films (SBFs) was investigated using antimicrobial activity, DPPH free radical scavenging values, scanning electron microscopy, X-ray diffraction, water vapor transmission rate, differential scanning calorimetry, and tensile strength. Likewise, it was depicted that the geometric and crystalline structures of medicinal plants' reinforced films remained the same even after processing. The mechanical tests indicated that the plant extracts effects are associated with reduced elongation, increasing tensile strength, and Young's modulus. Morphological analysis revealed the generation of uniform and the compact surfaces. However, films with 10% concentration of plant extracts have the lowest water vapor permeability values, and emerged better barrier properties. Moreover, these films showed the significant antioxidant potential and antimicrobial activity.

The effect of pine cone lignin on mechanical, thermal and barrier properties of faba bean protein films for packaging applications

In the present work, faba bean protein (FBP) films plasticized with glycerol and reinforced with different amounts (2.5, 5.0, 7.5 and 10% by weight of FBP) of lignin extracted from pine cones (PL) have been obtained by solution casting. The results obtained showed an elongation at break of 111.7% with the addition of 5% PL to the FBP film, which represents an increase of 107% compared to the FBP control film. On the other hand, it was observed by thermogravimetric analysis (TGA) that the incorporation of lignin improved the thermal stability of the FBP film, leading to an increase in the protein degradation temperature, being this increase higher in the sample film reinforced with 10% PL. The barrier properties of the FBP films were also affected by the presence of lignin, leading to a decrease in water vapor permeability (WVP) in comparison to the unreinforced film. The results show that the sample reinforced with 2.5% PL had the lowest WVP value, with a reduction of 25% compared to the control film. Chemical analysis by Fourier transform infrared spectroscopy (FTIR) confirmed the formation of intramolecular interactions between lignin and proteins which, together with the inherent hydrophobicity of lignin, resulted in a decrease of the moisture content in the films reinforced with PL. This research work has allowed the development of biobased and biodegradable films with attractive properties that could be of potential use in sectors such as packaging.

Green nanocomposite made from carboxymethyl cellulose reinforced with four types of cellulose nanomaterials of wheat straw

AbstractIn this study, four types of cellulose nanomaterials obtained from wheat straw including cellulose nanocrystals (CNCs), TEMPO oxidized cellulose nanofibers (TCNFs), mechanical‐driven cellulose nanofibers (MCNFs) and lignocellulose nanofibers (LCNFs) were first produced and then separately added to carboxymethyl cellulose (CMC) with different mixing ratio of 1, 3, and 6 wt% to make nanocomposite. Pure CMC film and cellulose microfibers (CFs) reinforced composite were also fabricated. BET test showed that TCNFs and CFs had the highest (124 m2/g) and lowest (3.6 m2/g) specific surface area, respectively. FE‐SEM confirmed that TCNFs and CFs presented the thinnest (8 ± 4 nm) and the thickest (24 ± 7 μm) fibers. The nanocomposite containing TCNFs had a transparency of 56%, while CF‐CMC composite showed the lowest one (18%). After the addition of cellulose nanomaterials the XRD peaks of nanocomposites became narrower and shifted partly to the right side compared to that of pure CMC. The highest and lowest water vapor permeability values obtained for rod‐like CNC reinforced nanocomposite and pure CMC film, respectively. The nanocomposite containing 6 wt% TCNFs showed the highest tensile strength and Young's modulus. Cellulose nanomaterials positively affected on the strain at break of the nanocomposites.

Investigation of Ultrasonic Treatment on Physicochemical, Structural and Morphological Properties of Sodium Alginate/AgNPs/Apple Polyphenol Films and Its Preservation Effect on Strawberry.

An antibacterial and anti-oxidation composite film was prepared by a casting method using sodium alginate (SA) and apple polyphenols (APPs) as the base material and glycerol as the plasticizer. Silver nanoparticles (AgNPs) were deposited by ultrasonic-assisted electrospray method. The degree of influence of the addition ratio of SA and AgNPs and different ultrasonic time on the mechanical properties, barrier properties, optical properties, and hydrophilicity of the composite film was explored. The composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the SA: AgNPs ratio of 7:3 and the ultrasonic time for 30 min have the best comprehensive performance, and SA/AgNPs/APP films showed the lowest water vapor permeability value of 0.75 × 10−11 g/m·s·Pa. The composite film has good strength and softness, with tensile strength (TS) and elongation at break (E) at 23.94 MPa and 29.18%, respectively. SEM images showed that the surface of the composite film was smooth and the AgNPs’ distribution was uniform. The composite film showed broad antibacterial activity, and the antibacterial activity of Escherichia coli (92.01%) was higher than that of Staphylococcus aureus (91.26%). However, due to the addition of APP, its antioxidant activity can reach 98.39%, which has a synergistic effect on antibacterial activity. For strawberry as a model, the results showed that this composite film can prolong the shelf life of strawberries for about 8 days at 4 °C, effectively maintaining their storage quality. Compared with the commonly used PE(Polyethylene film) film on the market, it has a greater fresh-keeping effect and can be used as an active food packaging material.

Efecto de la concentración de almidón y de aceite esencial de clavo de olor sobre las propiedades fisicoquímicas de películas biodegradables

Biodegradable films were obtained with the casting method using different concentrations of purple sweetpotato Ipomoea batatas (L.) starch and clove Syzygium aromaticum (L.) essential oil. Mechanical properties (tensile strength, percentage of elongation and Young's modulus), water vapor permeability and film adsorption isotherms were evaluated. In the formulations containing the intermediate concentrations of the components, a homogeneous surface, an improvement in fracture stress and a decrease in water vapor permeability were observed. The statistical analysis showed a significant difference in the mechanical properties of the composite films (p < 0.05). The GAB model was used to adjust the experimental data of the adsorption isotherms and a higher moisture content of the films containing the highest concentration of starch and essential oil was observed. The F6 (starch 3.5%, clove essential oil 60 mg/L) formulation showed the lowest water vapor permeability values (1x10-8 g/ m s Pa) and the lowest moisture content in the monolayer, which is considered to be the material with the best characteristics for its possible application, avoiding the excessive use of raw material during its preparation.

Thiol-branched graphene oxide and polydopamine-induced nanofibrillated cellulose to strengthen protein-based nanocomposite films

Soy protein isolate (SPI)—based composite materials possess a variety of excellent properties including biodegradability, biocompatibility, low cost, and easy availability, which have great potential for replacing petroleum-based materials. However, the inferior mechanical properties and high moisture sensitivity severely restrict their practical applications. In this study, novel integrated ternary hybrid nanocomposite films with multiple network structures were fabricated through introducing functionalized building blocks [graphene oxide (GO) sheets and nanofibrillated cellulose (NFC)] in a SPI matrix, in which, the interface interactions and building blocks worked synergistically to result in excellent integrated mechanical properties. First, the functionalized GO (SGO) sheets were successfully prepared via the thiol-ene click reaction with four-armed HS-terminated compound pentaerythritol tetra (3-mercaptopropionate) (PETMP) and were thus covalently cross-linked with catechol moieties of polydopamine layers on NFC (PNFC) by the Michael addition reaction. Then, the catechol moieties of PNFC covalently cross-linked to form the other crosslinked network with amino-containing SPI chains through Michael addition and/or Schiff base reactions. Moreover, H-bonding and π–π interactions also formed in such cross-linked networks. The resultant ternary SPI/SGO/PNFC films exhibited an optimal tensile strength of 11.10 MPa, which was nearly 2.81-fold higher than that of the neat SPI film. These films had the lowest water vapor permeability value of 3.91, which was 64.70% less than that of the neat SPI film. This work provides an effective and scalable design strategy for combining the synergistic effects of multiple building blocks and interfacial interactions and may show promise for various biomass applications.

Development of black and biodegradable biochar/gutta percha composite films with high stretchability and barrier properties

It is necessary to develop biodegradable composite films for reducing environmental pollution. Black and biodegradable biochar/gutta percha composite films were developed by adding different contents of biochar (0, 2, 4, 6 and 8%, w/w) into the gutta percha matrix. The results showed that the biochar effectively improved the hydrophobicity and mechanical properties compared with the control film. Moreover, the biochar/gutta percha composite films showed high stretchability and barrier properties. In particular, the 2% BC film had the highest tensile strength (18.3 MPa) and elongation at break (280.4%) and the lowest water vapor permeability value (0.09 × 10−9 g/m/h/Pa) at 34% relative humidity. However, the melting enthalpy (ΔHm) and crystallinity decreased. In addition, these composite films exhibited little electromagnetic interference shielding with a reflection loss up to −1.79 dB at 8.2 GHz. Finally, the composite films were more biodegradable than PE film after 60 days in soil.

Development, characterization and application of hydroxypropylmethylcellulose films enriched with cypress seed extract.

The phenolic profile of cypress seed extract (CSE) was investigated by means of liquid chromatography with photodiode array and electrospray ionisation mass spectrometric detection (LC/PDA/ESI-MS). The total phenolic (TP) and flavonoid (TF) contents as well as the antioxidant capacity of CSE were determined. The effects of CSE concentration (0.1, 0.3, 0.5, 1, and 2% (w/v)) on the functional properties of hydroxypropylmethylcellulose (HPMC) films were studied. Results showed that CSE presents a good antioxidant capacity due to its high phenolic/flavonoid contents and particularly the presence of bi-flavonoid compounds including cupressuflavone and amentoflavone derivatives. The incorporation of CSE in HPMC films led to a significant decrease in their water vapor permeability (WVP) and enhanced their mechanical strength. The lowest WVP value, the greatest opacity and the highest antioxidant capacity were obtained with the highest CSE concentration. HPMC films with and without CSE were applied on virgin olive oil to study their effect on the oxidative stability of olive oil during accelerated storage by periodically analyzing changes in FTIR spectra and peroxide values. HPMC-2% CSE films were the most effective in lowering light transmission, and consequently decreasing peroxide formation and delaying oxidation of olive oil.

The properties of potato and cassava starch films combined with cellulose fibers and/or nanoclay

The aim of this study was to develop and evaluate films produced from potato and cassava starches, reinforced with cellulose fibers and/or nanoclay. The films were elaborated with 4% starch, 30% glycerol, 20% cellulose fiber, and/or 5.0% nanoclay. The films were evaluated by physical, mechanical, and water vapor barriers, and morphological properties. The addition of nanoclay and cellulose simultaneously increased the tensile strength from 12.03 to 17.75 MPa and decreased the elongation from 13.81 to 0.94% of the potato starch films when compared to films without addition of these reinforcements. The addition of cellulose fibers and/or nanoclay increased the tensile strength of the cassava starch films. The water vapor permeability (WVP) of the films decreased with the addition of reinforcing agents, and the lowest WVP values were presented when cellulose and nanoclay were added simultaneously to the starch films. A synergistic effect between the cellulose and the nanoclay in the constitution of the film promoted a lower WVP value. The addition of cellulose increased the water solubility from 14.7 to 19.6% of the potato starch films. The addition of reinforcement agents in potato starch films produced more resistant films with a moderate solubility, thus can be used as a biodegradable sachet to release systems.

Water Vapor Permeability of Edible Films Based on Improved Cassava (Manihot esculenta Crantz) Native Starches

Starch is used in the production of edible biodegradable packaging as an attractive alternative to synthetic polymers because it is a natural biopolymer of low cost and high availability. Many studies have been carried out on films based on cassava starch and the results show that these have good flexibility and low water vapor permeability. This present research was conducted to analyse the effect of glycerol, peanut oil and soybean lecithin on the water vapor permeability (WVP) of edible films based on improved cassava (Manihot esculenta Crantz) native starches from Cote d’Ivoire. The films were prepared using 4 g cassava starch, 25% and 30% glycerol (w/w), 5% and 10% peanut oil (w/w) and 0% to 5% soybean lecithin (w/w oil) in Petri dishes. The WVP of the films was determined at 25°C and 75% relative humidity. The moisture content of the films was determined in an oven at 105°C and the film thickness was determined manually using a micrometer. The resulting films were homogeneous, transparent and crack-free. WVP, moisture content and thickness of the films increased with increasing glycerol concentration. Increasing the concentrations of the peanut oil and soybean lecithin decreased the thickness and increased the moisture content of the films. The combination of glycerol and peanut oil increased the WVP of the films, whereas addition of soybean lecithin had no effect. The lowest WVP values were obtained using 25% glycerol, 5% peanut oil and 5% soybean lecithin. Starch obtained from improved cassava varieties cultivated in Cote d’Ivoire can be a potential ingredient in the production of food packaging.

Properties of Gelatin Film from Horse Mackerel (Trachurus japonicus) Scale

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film-forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.45%, depending on the extraction conditions. Among the various extraction times and temperatures, the film from gelatin extracted at 70 °C for 1 h showed the highest tensile strength and elongation at break. Horse mackerel scale gelatin film showed the greatly low water vapor permeability (WVP) compared with mammalian or fish gelatin films, maybe due to its containing a slightly higher level of hydrophobic amino acids (total 653 residues per 1000 residues) than that of mammalian, cold-water fish and warm-water fish gelatins. Gelatin films from different preparation conditions showed excellent UV barrier properties at wavelength of 200 nm, although the films were transparent at visible wavelength. As a consequence, it can be suggested that gelatin film from horse mackerel scale extracted at 70 °C for 1 h can be applied to food packaging material due to its lowest WVP value and excellent UV barrier properties.

Physical evaluation of biodegradable films of calcium alginate plasticized with polyols

The influence of different polyols as plasticizers of alginate films on their physical attributes like moisture content, soluble mass in water, water uptake, water vapor permeability, opacity and mechanical properties were determined and the results discussed based on scanning electron microscopy observations and glass transition temperature. The alginate films were obtained by casting, using three different gramatures. Calcium crosslinked and non-reticulated films were considered. The films plasticized with glycerol and xylitol were more hygroscopic than the films with mannitol. The lowest water vapor permeability values were found for films plasticized with mannitol, at all studied thicknesses. The films plasticized with glycerol and xylitol showed very similar functional attributes regarding their application as food wrappings. The Ca2+ crosslinked mannitol films showed the highest tensile strength at rupture (>140 MPa).

The effects of ultrasonic/microwave assisted treatment on the water vapor barrier properties of soybean protein isolate-based oleic acid/stearic acid blend edible films

Edible films were prepared using soy protein isolate (4g/100 g), oleic acid (0–2 g/100 g) and stearic acid (0–2 g/100 g). Effects of the ratio of oleic acid to stearic acid and ultrasonic/microwave assisted treatment on the water vapor permeability (WVP) and contact angle of the prepared films were evaluated. Changes in the ratios of oleic acid to stearic acid had significant effects on WVP and contact angle (p < 0.05). It was found that the prepared films (oleic acid:stearic acid = 2:3) had the lowest WVP value (0.1 × 10−12 g cm−1 s−1 Pa−1) and highest contact angle value (135°), when the treatment temperature, time and power were 20 °C, 15 min, and 500 W respectively. Additionally, when OA and SA were added, the peak at 2920 cm−1 appeared, indicating a certain degree of interaction between the lipid and SPI.

다양한 가소제와 Ferulic Acid 처리한 Gelidium corneum 필름의 물성

다양한 가소제와 ferulic acid를 첨가한 GC 필름의 물성을 측정하였다. Glycerol, sorbitol, fructose, sucrose, PPG를 첨가한 필름의 WVP는 1.30～1.60 ng m/㎡sPa 범위를 나타내었는데, 가소제의 종류에 따라 값의 차이를 나타내었으며 sucrose를 첨가한 필름이 가장 낮은 WVP를 나타내었다. 필름의 TS와 %E는 각각 1.29～11.29 ㎫, 5.55～36.44%의 범위를 나타내었다. GC 필름에 가교제인 ferulic acid를 첨가하여 필름의 물성을 측정하였을 경우 WVP가 개선됨을 확인할 수 있었는데, 30 ㎎ ferulic acid 첨가 시 가장 낮은 WVP를 나타내었다. 10 ㎎ ferulic acid를 필름에 첨가하였을 때 대조구에 비해 매우 높은 TS를 나타내었지만 ferulic acid의 첨가량이 그 이상 증가함에 따라 TS는 감소하는 경향을 나타내어 ferulic acid를 10 ㎎ 첨가하는 것이 가장 최적의 농도라고 판단된다.

Edible films produced with gelatin and casein cross-linked with transglutaminase

In this study, transglutaminase was used to produce cross-linked casein, gelatin and casein–gelatin blend (100:0, 75:25, 50:50, 25:75 and 0:100) edible films. Cross-linking was investigated by SDS–PAGE. Mechanical and water vapor barrier properties of the films were characterized using ASTM procedures, and the film morphology was evaluated using scanning electron microscopy. The casein–gelatin film showed significant greater elongation values ( P < 0.05) with or without transglutaminase treatment, as compared to films made from gelatin or casein alone. Mixtures of casein and gelatin produced a synergistic effect only observed in the film elongation, while no improvement was detected for tensile strength and water vapor barrier properties, except for the casein:gelatin (75:25) formulation with transglutaminase, which showed the lowest water vapor permeability value (5.06 ± 0.31 g mm/m 2 d kPa). Enzymatic cross-linking also induced a substantial increase in the high molecular weight protein components in the film forming solutions.