Gelatin Films Research Articles

Effect of whey protein on thickness, water vapour transmission rate, and water content of gelatin film

Packaging is a tool used to protect products from physical damage; edible films can improve food quality and reduce plastic-based packaging materials. This study aimed to determine the effect of adding whey protein concentration on gelatin edible film thickness, water vapour transmission rate, and moisture content. This research used a completely randomized design with 4 treatments and 3 replications. The treatments consisted of P0 (0 g whey: 2 g gelatin), P1 (0.05 g whey: 2 g gelatin), P2 (0.10 g whey: 2 g gelatin), P3 (0.15 g whey: 2 g gelatin). The addition of whey protein had a significant effect (P<0.01) on the thickness of the gelatin film. However, no significant effect (P>0.05) was found on the water vapour transmission rate and moisture content. Nonetheless, employing whey protein can reduce the water vapour transmission rate and increase the moisture content of edible gelatin film. The findings suggest that incorporating whey protein can enhance the physicochemical properties of gelatin films. Using whey protein at a concentration of 0.05 g is deemed the optimum treatment.

Effect of edible film gelatin nano-biocomposite packaging and storage temperature on the store quality of strawberry (Fragaria x ananassa var.duchesne)

An edible film is a type of bioplastic packaging that can be used to package strawberries. Therefore, this study aimed to determine the packaging effect using nanobiocomposite edible film based on gelatin/nanocrystalline cellulose with the addition of antioxidants nanopropolis and storage temperature on the quality and shelf life of strawberries. The strawberries fruit were packed with edible film nanobiocomposite and stored at 5 °C, 10 °C, and 30 °C. The parameters analyzed were water content, Vitamin C, hardness, total dissolved solids, pH, and shelf life. The results showed that the water content ranged from 23.95 to 65.89%w/b at the end of the storage period and was stable at 5 °C and 10 °C. The decrease in water content occurs very quickly at a storage temperature of 30 °C and control. Furthermore, hardness at the end of storage ranged between 0.265 – 0.431 kg/cm² and the fastest decrease in hardness occurred at storage at a temperature of 30 °C. All treatments experienced a decrease in Vitamin C content during storage. The total dissolved solids content at the end of storage was 5.92–12%Brix, with a shelf life ranging from 3 to 21 days of storage, as determined by all treatment parameters. Bionanocomposite edible gelatin film packaging with added nanopropolis can increase shelf life to 21 days of storage. These results showed that bionanocomposite edible film gelatin packaging can increase the shelf life of strawberries.

Enhancing physicochemical, antimicrobial, and release properties of fish skin gelatin films using dual-layer nanoparticles loaded with tea polyphenols/kojic acid for air-dried chicken preservation

This study investigated the effects of the physicochemical, antimicrobial and release properties of fish skin gelatin (FG) films by dual-layer nanoparticles containing tea polyphenols/kojic acid, and their application in air-dried chicken preservation. Dual-layer nanoparticles were prepared by layer-by-layer (LBL) self-assembly technique, yielding an average particle size of 365.4 nm. Atomic force microscopy confirmed the compatibility between the nanoparticles and the film matrix. Spectroscopic and X-ray analyses provided insights into hydrogen bond formation between the nanoparticles and the film matrix, supported by molecular docking studies, and the FG film with nanoparticles exhibited improved tensile strength, thermal stability, UV-blocking properties, and hydrophobicity. The composite film showed potent antimicrobial activity against spoilage bacteria, antioxidative effects, and controlled release behavior. In vitro toxicity tests confirmed the film's safety, which was then used to preserve air-dried chicken. High-throughput sequencing analysis indicated its effectiveness in suppressing spoilage bacteria like Brochothrix and Psychrobacter, influencing bacterial population distribution during storage. These findings hold strategic significance for improving active food packaging materials that incorporate food-derived nanoparticles into reinforced biofilms.

Brillouin Scattering Study of Gelatin Films with Different Water Concentrations

The gigahertz longitudinal elastic modulus of hydrated gelatin films as a function of water content was studied using Brillouin spectroscopy. It was found that the elastic modulus increases with increasing protein concentration. Two ranges can be distinguished with different concentration behavior, which are associated with different proportions of bonded water molecules. The addition of glutaraldehyde has very little effect on the elastic modulus of hydrated gelatin films.

Study of the Mechanical Properties of Gelatin Films with Natural Compounds of Tamarix hispida

In this work, an extract of the Tamarix hispida (TH-10) was prepared in 10 vol.% water-ethanol solution. Based on the properties of antioxidant, and anti-inflammatory activity, various gelatin films containing (10–15 wt.%) gelatin were obtained. The fabricated gelatin films containing TH-10 extract were used as wound dressings for burns. Their deformation properties, physical and mechanical properties, and SEM micrographs were defined. An additional film structure was determined by using a Fourier transform infrared spectrometer (FT-IR). The strength of polymer films containing TH-10 depends on gelatin content. This indicates that the gelatin film binds the TH-10 with the help of hydrophobic interactions. It was found that the higher amount of gelatin leads to lower tear resistance of films. This is due to the formation of micro-cracks on the surface of films leading to their easy rupture. During the study of tensile strength, it was proven that the optimal amount of glycerin in the film is 5 vol.%. The polymer film containing 12 wt.% gelatin and 1 wt.% TH-10 was recognized as the most effective composition in terms of strength and elasticity properties for application as wound dressing materials.

Development and Characterization of Edible Films Based on Gelatin/Chitosan Composites Incorporated with Zinc Oxide Nanoparticles for Food Protection

The increase in cases of global environmental pollution due to plastic waste makes the development of biodegradable active packaging very urgent. Gelatin (G), is one of the potential edible film raw materials. However, its weak water barrier and mechanical properties have limited its wide application. The addition of chitosan nanofiber (CHNF) and zinc oxide nanoparticles (ZnONP) is expected to improve the mechanical and barrier properties and present antioxidant and antimicrobial properties to the G film. Characterization results using FTIR, SEM, and DSC showed good compatibility between the G, CHNF, and ZnONP matrix. Meanwhile, the packaging test results confirmed that gelatin, CHNF, and ZnONP-based composite films have the potential to be used as functional materials in food packaging.

Evaluation of a Fish Gelatin-Based Edible Film Incorporated with Ficus carica L. Leaf Extract as Active Packaging.

The significant concerns associated with the widespread use of petroleum-based plastic materials have prompted substantial research on and development of active food packaging materials. Even though fish gelatin-based films are appealing as active food packaging materials, they present practical production challenges. Therefore, this study aimed to develop an edible film using Ficus carica L. leaf extract (FLE), as it is affordable, accessible, and has superoxide anion radical scavenging action. This edible film was produced by adding FLE to mackerel skin gelatin at varied concentrations (2.5-10% w/w). The results showed that adding FLE to gelatin films significantly affected the tensile strength (TS), elongation at break (EAB), transmittance and transparency, solubility, water vapor permeability (WVP), antioxidant activity, and antibacterial activity. Among all the samples, the most promising result was obtained for the edible film with FLE 10%, resulting in TS, EAB, solubility, WVP, antioxidant activity, and antibacterial activity against S. aureus and E. coli results of 2.74 MPa, 372.82%, 36.20%, 3.96 × 10-11 g/msPa, 45.49%, 27.27 mm, and 25.10 mm, respectively. The study's overall findings showed that fish gelatin-based films incorporated with FLE are promising eco-friendly, biodegradable, and sustainable active packaging materials.

Ultra-sensitive gas pressure and temperature sensor based on self-forming film technique and vernier effect

In this paper, an ultra-sensitive gas pressure and temperature sensor based on vernier effect is presented. It consists of a single mode fiber (SMF) and hollow cylindrical waveguides (HCW). Through the self-forming film technique, a gelatin film is manufactured at the air core of HCW, and the thickness of the gelatin film manufactured by this technique is only 3.16 μm. The vernier spectrum is formed by the superposition of the spectra of the air cavity (AC) and the mixing cavity. The mixing cavity is composed of AC and gelatin cavity (GC). The thin gelatin film makes the optical path difference between the AC and the mixing cavity smaller, which is beneficial to increase the vernier magnification factor. When the gas pressure changes, the gelatin film will deform abnormally. This abnormally deformation squeezes the film, causing the cavity length of the air cavity to become longer. The experimental results show that the sensor exhibits a high gas pressure sensitivity of 788.22 nm/MPa, and the temperature sensitivity is 0.39 nm/℃. The proposed sensor enables simultaneous measurement of gas pressure and temperature. It also processes the advantages of compact size, low cost, and strong mechanical strength, which makes it suitable for aerospace, Biomedical and Natural gas detection.

Optimization and characterization of biodegradable films from chicken gelatin crosslinked with oxidized phenolic compounds

Chicken gelatin derived from poultry by-product was combined with caffeic acid (CA), rutin (RUT) and glycerol (GLY) to obtain biodegradable films. Optimum cross-linking conditions were investigated using Response Surface Methodology (RSM). The results showed that cross-linking led to lower L* value and higher b*, and the higher opacity values in the films. Water solubility (WS) decreased up to 50% after the incorporation of 1.25% CA compared to the commercial gelatin (cattle and pig based) films. Crosslinking improved the thermal stability and the tensile strength (TS) of films. Optimized cross-linking combination was determined as 0.96–1.56% CA, 0–1.25% RUT, and 29.5–30.5% GLY. Overall, this study demonstrated that crosslinking by CA and RUT can be used to improve the physical and barrier properties of gelatin films having excellent potential for the development of biodegradable films for packaging uses. These films may also result in an improvement and added value in poultry by-products.

Development of electrospun fish gelatin film containing lauroyl arginate ethyl and its application in large yellow croaker (Pseudosciaena crocea) preservation

Development of electrospun fish gelatin film containing lauroyl arginate ethyl and its application in large yellow croaker (Pseudosciaena crocea) preservation

Estimate of the random match frequency of acquired characteristics in footwear: Part II — Impressions in dust

This study serves as Part II of an investigation into the random match frequency of randomly acquired characteristics (RAC-RMF) in footwear evidence. In Part I, RAC-RMF was estimated in a dataset of laboratory-simulated crime scene impressions deposited in blood. For Part II, a second dataset was created composed of impressions deposited in dust on paper or tile, with the latter lifted using gelatin or Mylar film. A total of 1,513 RACs were identified from more than 160 dust impressions and compared to RACs with positional similarity in test impressions from 1,299 non-mated outsoles. RACs of any size deposited in dust exhibited a 31% decrease in shoes with non-zero RAC-RMFs as compared to their mated test impressions, while those deposited in blood exhibited a 45% increase. When only considering shoes with at least one RAC deemed forensically-reliable (length ⩾ 2.8 mm), 3.1% of shoes contributing dust impressions and 3.4% of shoes contributing blood impressions exhibited relative RAC-RMFs at a value ⩾ 0.0008. Although each dataset resulted in a comparable rate for encountering non-zero RAC-RMFs, the estimate for dust was based on twice the number of RAC comparisons (154,477) than those performed when assessing blood (77,566). While these results are considered specific to the non-mated impressions and methods of analysis described herein, and continued work is required before rates can be fully understood and reported in forensic casework, this study encountered non-zero RAC-RMFs for shoes exhibiting at least one forensically-reliable RAC at a more frequent rate than any estimates previously reported.

Preparation of gelatin-chitosan bilayer film loaded citral nanoemulsion as pH and enzyme stimuli-responsive antibacterial material for food packaging

The responsive release of enzymes, pH, temperature, light and other stimuli is an effective means to reduce the loss of volatile active substances and control the release of active ingredients. The purpose of this study is to design a simple and rapid method to synthesize a multifunctional bilayer membrane, which has good mechanical properties, long-lasting pH and enzyme dual sensitive sustained release properties, and excellent antibacterial activity. The citral nanoemulsion was prepared by ultrasonic method, then the chitosan solution loaded with nanoemulsion was assembled on the gelatin film, and the uniform and smooth gelatin-chitosan bilayer film was successfully prepared. Compared with the control group, the bilayer film loaded with nanoemulsion showed better barrier performance, mechanical properties and antibacterial activity.

Characterization of gelatin films functionalized with silver nanoparticles or polysorbate 20 as UV–vis light controllers

Given its versatility as a biopolymer, fish gelatin has numerous industrial applications and there is significant interest in modifying its properties to broaden its potential uses. The primary aim of our study is to investigate the individual effects of two additive agents on rheological, thermomechanical, and physicochemical properties of fish gelatin films. The selected additive agents were: 1) silver nanoparticles [0.61, 0.91 and 1.22 nmolAgNP•m−2] and 2) polysorbate 20. Rheological and physicochemical characterizations of the fish gelatin filmogenic solutions were performed. Rheological results showed that both the addition of silver nanoparticles and polysorbate 20 generate similar results such as non-Newtonian behavior at 40 °C and a cutting speed of 1–100 1/s; as well as liquid film-forming solutions in the angular frequency range between 1 and 600 rad/s. However, substantial differences were found in the effects generated on the thermomechanical properties, physicochemical properties, and UV-Vis barrier effect. The increase in content of silver nanoparticles to 1.22 nmolAgNP•m−2 generated a higher increase in glass transition temperature and modulus of elasticity compared to the polysorbate treatment. In contrast, the incorporation of polysorbate leads to higher opacity than the incorporation of silver nanoparticles; thus a better barrier effect against visible and UV light in the range from 300 to 1000 nm. In conclusion, the results obtained indicate that the incorporation of silver nanoparticles or polysorbate manages to modify the functionality of fish gelatin films, expanding their potential applications as packaging materials.

Engineering biodegradable controlled gelatin-zein bilayer film with improved mechanical strength and flexibility

Compiling hydrophobic and hydrophilic proteins to form mechanically reliable bilayer film with improved water barrier properties and hydrophobicity to replace petroleum-based standards is challenging because fabricating compatible surfaces and flexible film with interlinked interfaces is complex. The mechanical properties of gelatin and zein layers exhibited unique variations, and synergistic enhancement of bilayer properties reflected robust layer-by-layer (LBL) interactions. To overcome the problem of impaired integrated surface, viscously cross-linked zein film forming solution (FFS) by glyoxal (GX) introduced compact and closely entangled network formation with cross-linking of gelatin film. Zein surface compatibility and flexibility by GX and polyethylene glycol (PEG 400) synergized with the gelatin layer closed to compare flexible plastic materials such as PE and PP besides modulated color and transparency. Enhancing flexible formation was mechanized by acetic acid as solvent of zein solution after long-range repulsion during casting on well-manageable plasticized and cross-linked gelatin film with glutaraldehyde (GA) and PEG 400, respectively. Elongation (E%) was achieved by nearly 192% with modified tensile strength (TS) and Young's modulus (YM). Cross-linkers, especially GX, resulted in lower water solubility (WS), and joint layers resulted in controlled water vapor permeability (WVP) of bilayer films. Decreased surface roughness and WS increased water contact angle (WCA). FTIR spectroscopy, XRD analysis, DMTA, and SDS-PAGE analyzed cross-linking mode and intensity. Hence, gelatin-zein bilayer films showed significant potential for improving value-added functional properties.

Improvement of biodegradable polymer film properties by incorporating functionalized few-layer graphene

Functionalized few-layer graphene (FFG) prepared employing an eco-friendly liquid exfoliation method using coffee waste extract was added to three biological and one synthetic polymers. Chitosan/FFG, polyvinyl alcohol (PVA)/FFG, sodium alginate/FFG, and gelatin/FFG composite films were developed using variable concentrations of FFG (0–1 wt% of polymer). The developed films were characterized for water content, swelling degree, thickness, thermal and mechanical properties, water vapor permeability, and indoor soil burial degradation. In comparison to the pure chitosan, PVA, sodium alginate, and gelatin films, the inclusion of FFG significantly increased the tensile strength up to 439%, 247%, 190%, and 195%, respectively. Moreover, the Young’s modulus of the developed composite films was improved up to 515%, 253%, 144%, and 341%, respectively. The elongation at break of chitosan and PVA films declined with FFG concentration, while the maximum elongation at break existed for sodium alginate/FFG and gelatin/FFG films. The water vapor permeability of chitosan, PVA, sodium alginate, and gelatin composite films decreased by 87%, 67%, 50%, and 55%, respectively, with the addition of only 1% FFG. The incorporation of FFG reduced both the water content and swelling degree of all composite films. In addition, the composite films showed similar degradation after addition of FFG in the 60-day soil burial test.

Properties of Allicin-Zein Composite Nanoparticle Gelatin Film and Their Effects on the Quality of Cold, Fresh Beef during Storage.

Allicin is a kind of natural antimicrobial active substance, but its water solubility is poor, and it is easy to degrade. In order to improve the stability and bioavailability of allicin, allicin-zein composite nanoparticles (Al-Ze) were prepared by the combination method of antisolvent precipitation and electrostatic deposition, and their characteristic parameters, such as average particle size, polydispersity index (PDI), and ζ-potential, were analyzed. Then, Al-Ze was used as the delivery carrier for the active substance (allicin), and gelatin with good film-forming properties was selected as the film-forming matrix to prepare Al-Ze gelatin films. The optical properties, mechanical properties, and characterization parameters were used to analyze the prepared composite materials; the results confirmed that Al-Ze gelatin film has good mechanical properties and barrier properties. The prepared film was applied to the storage of cold, fresh beef, and the quality change of beef was monitored at 4 °C. The results showed that Al-Ze gelatin film could effectively delay the quality deterioration of beef. This paper provides a new idea and data support for the application of Al-Ze gelatin film in meat storage and fresh-keeping, and offers new insight for the promotion and application of allicin in the food industry.

Chitin nanowhisker-containing photo-crosslinked antimicrobial gelatin films

Nearly 57 Mt of food waste are generated annually in the EU for many reasons, for instance, because of microbial food spoilage. So, actions to reduce food loss and waste are needed and active packaging could offer a new approach towards this aim. In this study, antimicrobial gelatin films were prepared via the solution casting technique and their physicochemical, optical, mechanical, structural, barrier and antimicrobial properties were analysed. First, gelatin films were photo-crosslinked with riboflavin and the photo-curation time (0–4 h) was optimized. The optimal crosslinking time was 2 h since the solubility dropped down from 100% to 30% after 2 or 4 h of UV exposure. Then, 2 types of chitin nanowhiskers (CNWs) obtained via acid hydrolysis (AH) and TEMPO-mediated oxidation processes were added in 2 concentrations (2 and 4 wt %) into the film-forming solution (FFS) as reinforcements before film photo-crosslinking. The AH-CNW at 4 wt % was chosen as an optimal CNW type and concentration because they further decreased the solubility (∼24%) of films and improved mechanical properties up to values similar to those of commercially available synthetic packaging films. Finally, various concentrations (0, 7.5, 15 and 30 wt %) of the antimicrobial compound (Nisin A®) were added to the optimized formulation which showed good antimicrobial properties on both spoilage and pathogen strains, as well as over the native microbiota of chilled sea bream fillets, sliced cold-smoked salmon and chicken breast fillets. The developed films displayed promising properties as antimicrobial packaging for myosistem foods.

Cross-linked gelatin–riboflavin-based film incorporated with essential oils and silver nanoparticle by gamma-irradiation: A novel approach for extending the shelf life of meat

The gamma-irradiation is one of the most acceptable technologies to modify the biopolymer structure by forming a highly energetic electron. The effect of gamma-irradiation for cross-linking of gelatin (G) film in the presence of riboflavin (R) and the physicochemical properties of films were investigated. Different concentrations of R (0.3, 0.75, and 1.2% (w/w) based on the dry weight of G) and 3 doses of gamma-irradiation (5, 10, and 15 kGy) were used. The cross-linked film was incorporated with a mixture of essential oils (EOs) and silver nanoparticles (AgNPs) in order to use as an active packaging for prolonging the shelf life of meat. The results indicated 0.75% R (w/w) and 5 kGy irradiation had a positive effect on the tensile strength, water insolubility, and water barrier properties of the composite G film. Nevertheless, the reduction of film elongation (%), suggests the formation of compact structure and cross-linking through the generation of radicals. The infrared spectroscopy evaluation showed that proper irradiation dosages could produce cross-linking bonds in G film and form a denser network. In vitro and in situ microbial analyses showed that the active film incorporated with EO-AgNPs had antimicrobial activity against most spoilage and pathogenic bacteria and was able to prolong the shelf life of meat by up to 21 days. Therefore, irradiated G-R-EO-AgNP film with good mechanical and antimicrobial properties has the potential to be developed as a biodegradable food packaging material in the food industry.

Preparation and characterization of nano-SiO2-modified emulsified film and its application for strawberry preservation

To extend the shelf-life of strawberries, this study analyzed the effect of nano-SiO2 on a composite film of gelatin (GE) and Camellia oil (CO). The emulsified film properties of GE and CO containing various nano-SiO2 mass fractions were investigated. Results demonstrated that 5% nano-SiO2 increased compatibility with GE and CO, produced a smooth and structurally dense film, and enhanced thermal stability and mechanical properties. Moreover, 5% nano-SiO2 improved barrier properties. The water vapor permeability, oxygen permeability, carbon dioxide permeability, and oil permeability decreased by 72.95%, 17.44%, 17.27%, and 18.68%, respectively, compared with those in the GE emulsified film. Strawberries sealed with an emulsified film containing 5% nano-SiO2 showed the maximum suppression in weight loss rate and lipid oxidation of strawberries, and the highest maintenance in respiration intensity, peroxidase, and catalase activities. The above results revealed that nano-SiO2 enhances the functionality of emulsified films, and composite films are potential packaging materials for extending the shelf life of strawberries.

Плёночные материалы на основе желатина, содержащие растительные экстракты

Polymer films based on traditional synthetic polymers are widely used throughout the world. However, the impossibility of biodegradation of synthetic polymers in the environment and, as a result, the accumulation of polymeric waste stimulates using biodegradable bio-based polymers instead of traditional ones. One of them is gelatin. Gelatin is biodegradable, it has good mechanical and barrier properties, high film forming ability and widely distributed. Presented research includes results of a investigation of gelatin films based on aqueous extracts from the leaves of sea buckthorn leaves, plantain leaves, pine needles (film based on distilled water used as a control). The qualitative and quantitative composition of polyphenolic compounds (the sum of polyphenols, flavonoids and tannins) that make up the extracts was determined using physico-chemical methods of analysis. The antioxidant activity of plant extracts has been established. The highest amount of antioxidants (64 mg/100 сm 3 ) was found in extracts from sea buckthorn leaves. Using plant extracts in the composition of gelatin films did not cause significant changes in their thermal stability; it was confirmed by thermogravimetric analysis. Significant changes in properties compared to the control were noted for samples containing sea buckthorn leaf extract. Thus, the value of the stress at break was 11.6 MPa, and the elongation at break was 100% (11.4 MPa and 65% for control, respectively). For all the studied samples, there was a lower water absorption (200–223% after 60 minutes) compared to the control (254% after 60 minutes) and vapor permeability values comparable to the control. Such combination of film properties, with a high content of antioxidants in plant extracts, allows us to consider these materials as promising for the creation of biodegradable packaging films with antibacterial activity.