Gelatin Films Research Articles

Functional Properties of Tilapia’s Fish Scale Gelatin Film: Effects of Different Type of Plasticizers

The aim of this study was to investigate the functional properties of Tilapia’s fish scale gelatin films with various type of plasticizers. Gelatin film solutions using solution casting method with different type of plasticizers; glycerol, sorbitol, glycerol: sorbitol (80:20), and diethylene glycol with concentration of 30% were stirred at 60 °C for one hour and dried at room temperature for 2 days. The determination of film characterizations was included thermal (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)), mechanical testing using the Texture Analyzer and chemical properties (Fourier transform infrared spectroscopy (FTIR)). Essentially, all plasticizers show an improvement by able to plasticizing with increasing of elongation at break in between 14 and 50% compared to the gelatin film without plasticizer. Meanwhile, the tensile strength of plasticized gelatin films decreased drastically compared to the unplasticized gelatin film. From the result obtained in TGA analysis, film with sorbitol and dietheylene glycol demonstrated low resistance toward high temperature compared to film with glycerol and glycerol:sorbitol gelatin film. In addition, all the gelatin film with different plasticizers show the value of Tg around 60-70.85 °C except for sorbitol with Tg 79.98 °C due to strong intermolecular chain interaction between the sorbitol and gelatin. FTIR spectrum analysis demonstrated that only gelatin film with glycerol does not have any amide group that related to stretching vibration of carbonyl group along the polypeptide backbone of the plasticized film which later give highest tensile strength. Hence, notable differences of functional properties were found with four different type of plasticizers used in the gelatin film, especially in term of temperature resistance and mechanical properties

Potential of Silver-Kaolin in Gelatin Composite Films as Active Food Packaging Materials

This study discovered the potential application of kaolin (Kln) and silver-kaolin (Ag-Kln) in gelatin-composite films as active packaging material for food products. Three different types of kaolins; raw Kln, Ag-Kln (1:2) mix and Ag-Kln (1:1) mix with various concentrations (15%, 30% and 45%) were prepared by solution casting. For the water barrier properties, the wettability test indicated that the addition of kaolin in gelatin films produced hydrophobic films and lower (p < 0.05) water vapour permeability, regardless of the kaolin type and concentration. Scanning electron microscopy images portrayed that higher inclusions of Ag-Kln compounds are able to develop smoother surface and homogenous cross-section. In addition, by incorporating these two materials, films with great antimicrobial effect towards both Gram-positive and Gram-negative bacteria were produced. Elevation of Ag-Kln concentration also proved to lower the transmission of ultraviolet-vis light through the films. These findings suggested that gelatin film with Ag-Kln has a potential and beneficial in food packaging industry due to its enhanced properties.

Application of soymilk skin as sausage wrapping for improving lipid oxidation.

Yuba, the soymilk skin, was developed as edible films for sausage. Yuba (Y) were prepared with added pine-needle extract (YP) and employed to wrap sausage. Physical and mechanical properties and lipid oxidation of sausages were compared to sausages made with commercial collagen casing (C). Y films showed better transparency, oxygen-barrier properties, and UV-light barrier properties than C films (p < .05). Particularly, the addition of pine-needle extract increased DPPH activities from 31 to 48% and total phenol content from 7.52 to 14.64 mg gallic acid/g. Regarding application for sausage wrapping, Y (2.35%) and YP (2.66%) wrapped sausages with better protection against water loss during cooking compared to sausages made from C (5.84%). Especially, YP (3.57 MDA mg/kg) showed better protection against lipid oxidation for sausages than Y (4 MDA mg/kg) and C (4.62 MDA mg/kg) on day 6 after refrigerated storage. Yuba films could be employed as potential alternatives to gelatin films for manufacturing sausages.

Gelatin-based functional films integrated with grapefruit seed extract and TiO2 for active food packaging applications

Gelatin-based functional films were prepared by the addition of grapefruit seed extract (GSE, 5 wt% based on gelatin) and various amounts of TiO2 (0.5, 1.0, 3.0, and 5.0 wt% based on gelatin). TiO2 was evenly dispersed in the gelatin film, but the film surface roughness was increased as the concentration of TiO2 increased. The mechanical strength and water contact angle (WCA) of the composite film were the highest, while the water vapor permeability (WVP) was the lowest when 0.5 wt% TiO2 was used. The addition of GSE slightly reduced the UV light transmittance, but the addition of TiO2 almost completely prevented the UV light transmission. The addition of GSE and TiO2 did not significantly influence the thermal stability of gelatin film. The Gel/GSE/TiO2 composite film showed some antioxidant activity and strong antibacterial activity against E. coli and L. monocytogenes, mainly due to the GSE. The gelatin/GSE/TiO2 composite films with high UV-barrier and antimicrobial functions with some antioxidant activity are likely to be used for active food packaging applications.

Physical properties and bioactivities of fish gelatin films incorporated with cinnamaldehyde-loaded nanoemulsions and vitamin C

In this paper, the natural antibacterial agent cinnamaldehyde (CA) was made into nanoemulsions to improve its water solubility. Subsequently, the active gelatin (GL-CA-Vc) films with antibacterial and antioxidant activities were prepared by combining silver carp skin gelatin with CA nanoemulsions and vitamin C (Vc). Compared with the gelatin control (GL-Control) film, the thickness, roughness and water vapor permeability (WVP) of active films increased significantly. In addition, the elongation at break (EAB) and light barrier property of active films were also enhanced. The antibacterial and antioxidant activities of active films were related to the content of active additives. The film containing 100 mg of CA and 50 mg of Vc (GL-100CA-50Vc) had good light barrier property and a high EAB (158.00 ± 12.51%). What's more, the inhibition rate of GL-100CA-50Vc film against Pseudomonas aeruginosa was 55.97 ± 4.25%, and the free radical scavenging rate of the film to ABTS and DPPH was 96.26 ± 0.72% and 95.74 ± 0.20% respectively, which indicated that the film had good antibacterial and antioxidant activities.

Preparation and Properties of Cationic Gelatin Cross-Linked with Tannin

A kind of biomaterial with antibacterial and mechanical properties was prepared using gelatin (GE) as a raw material. GE was modified by antibacterial epoxy quaternary ammonium salt (QAS) and then cross-linked with tannic acid (TA). Analysis of the Fourier transform infrared spectroscopy (FTIR) results showed that the cationic group was grafted onto GE by reaction of the amino of GE with the epoxy of QAS, and the cross-linking occurred between the amino of GE and the active groups of TA under alkaline conditions. The cross-linking degree was determined by the fluorescence method via a derivative reaction of fluorescamin. The influence of the cross-linking degree on the physical and chemical properties of the GE film was studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and mechanical testing. The results showed that the modified GE film formed a compact cross-linking structure, and its thermostability and mechanical properties were improved with increasing cross-linking degree. The in vitro antibacterial rate of the cross-linked cationic GE film to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reached 95.83% and 100% respectively, and the in vitro cell relative growth rate (RGR) of HeLa cells cultured in the extracted leachate of the cross-linked cationic GE film exceeded 85%, which illustrated that the modified GE film had excellent antibacterial activity and biocompatibility.

Mechanical, physical, and bio-functional properties of biopolymer films based on gelatin as affected by enriching with orange peel powder

In the present study, bio-functional edible films were developed by incorporating different concentrations (0, 3, 6, 9, 12, and 15%) of orange peel powder (OPP) into the gelatin. The thickness, moisture content, and water vapor permeability of the gelatin films enhanced as the content of incorporated OPP increased. OPP-incorporated films showed lower L* value, but higher a*, b*, and opacity values. Films with higher concentration of OPP showed higher strengths and lower elongation properties. The surface and cross-sectional microstructure of films were also characterized by scanning electron microscopy. The antioxidant properties of films including total phenolic content, ABTS radical scavenging activity, and reducing power were significantly improved by enriching with OPP. The incorporation of OPP also increased the antimicrobial activity of gelatin films against Staphylococcus aureus and Escherichia coli. These results suggested that the orange peel has a good potential to be incorporated into gelatin to produce bioactive packaging films which will be helpful to maintain the quality of the packaged food products.

Effects of nisin concentration on properties of gelatin film‐forming solutions and their films

SummaryThe addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin‐based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film‐forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin‐based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g−1 of gelatin.

Influences of four kinds of calcium salts on the functional performances of gelatin composite films

Fish gelatin films were prepared with gelatin as the main raw material and four kinds of salts, including CaCl2, CaSO4, hydroxyapatite and Ca3(PO4)2, as the auxiliary reagents. The types of the anions and the concentrations of the calcium salts could affect the light transmission, swelling ratio, tensile strength, and elongation at break of gelatin films. The relationship between them was studied in this paper. The experimental data were analyzed and it is noted that the swelling ratio of the gelatin film was improved after adding the calcium salts. The swelling ratio of the hydroxyapatite/gelatin composite film was significantly bigger than that of other composite films. There is no significant effect on the light transmittance of the gelatin film after adding the calcium salts. The improved mechanical performances were found in the composite gelatin films by adding calcium chloride, calcium sulfate, and calcium phosphate. In comparison, calcium phosphate performed the greatest influence on improving the mechanical performances of the composite films.

Study on the stability and cellular affinity of gelatin-polysaccharide composite films.

The gelatin film has great potential in biomedical applications, especially in wound healing. The combination of gelatin films and stem cells could further accelerate the skin regeneration. Although polysaccharide modification can improve the mechanical property and biological activity of gelatin films, information about the stability and cellular affinity is still limited. This study investigated the influence of polysaccharides on the stability and cellular affinity of gelatin films. Two kinds of gelatin-polysaccharide composite films, including gelatin-hyaluronic acid (G-HA) and gelatin-chitosan (G-CS), were prepared in this study. It was found that G-HA composite film had better short-term and long-term stability compared with G-CS composite film. And G-HA composite film also had better biological safety than G-CS film. Moreover, the surface of G-HA composite film supported the adhesion and growth of human umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ MSCs) better than G-CS film surface. These data illustrated that G-HA composite film has better stability and cellular affinity compared with G-CS film, which could be considered a promising delivery system of stem cells for further in vivo studies. Therefore, this work would be very helpful to optimize the preparation of gelatin-polysaccharide composite films.

Application of Nanoemulsions (W/O) of Extract of Opuntia oligacantha C.F. Först and Orange Oil in Gelatine Films.

Over the past decade, consumers have demanded natural, completely biodegradable active packaging serving as food containers. Bioactive plant compounds can be added to biopolymer-based films to improve their functionality, as they not only act as barriers against oxidation, microbiological, and physical damage, they also offer functionality to the food they contain. A water-in-oil (W/O) nanoemulsion was produced by applying ultrasound to xoconostle extract and orange oil, and was incorporated into gelatine films in different proportions 1:0 (control), 1:0.10, 1:0.25, 1:0.50, 1:0.75, and 1:1 (gelatine:nanoemulsion). The nanoemulsions had an average size of 118.80 ± 5.50 nm with a Z-potential of −69.9 ± 9.93 mV. The presence of bioactive compounds such as phenols, flavonoids, and betalains in the films was evaluated. The 1:1 treatment showed the highest presence of bioactive compounds, 41.31 ± 3.71 mg of gallic acid equivalent per 100 g (GAE)/100g for phenols, 28.03 ± 3.25 mg of quercetin equivalent per 100 g (EQ)/100g flavonoids and 0.014 mg/g betalains. Radical inhibition reached 72.13% for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 82.23% for 1,1-diphenyl-2-picrylhydrazyl (DPPH). The color of the films was influenced by the incorporation of nanoemulsions, showing that it was significantly different (p < 0.05) to the control. Mechanical properties, such as tensile strength, Young’s modulus, and percentage elongation, were affected by the incorporation of nanoemulsified bioactive compounds into gelatine films. The obtained films presented changes in strength and flexibility. These characteristics could be favorable as packaging material.

MECHANICAL AND PHYSICAL PROPERTIES OF BIO-NANOCOMPOSITE FILMS BASED ON CHICKEN SKIN GELATIN WITH DIFFERENT CONCENTRATION OF CHITOSAN NANOPARTICLES

Plastics packaging is non-biodegradable and risks to human health and environmental pollution. In contrast, gelatin-based film lack of desired mechanical, thermal and water vapour barrier properties. Thus, this study aimed to investigate the mechanical and physical properties of bio-nanocomposite films based on chicken skin gelatin with different concentration of chitosan nanoparticles (CSNPs). Gelatin/CSNPs film solutions with different CSNPs concentration (0-8%, w/w) were stirred at 45oC for 30 min and oven-dried at 45oC. Film characterization determination includes tensile strength (TS), elongation at break (EAB), Young&amp;rsquo;s modulus (YM), water solubility, water vapour permeability (WVP), film morphology and melting temperature (Tm). Results of the study indicated that incorporation of CSNPs significantly influenced film properties. The addition of CSNPs increased the TS and YM value, which lead to stronger films than the pure chicken skin gelatin films. However the addition of CSNPs decreased the EAB value. Furthermore, WVP and water solubility significantly decreased (p &amp;lt; 0.05) by the addition of 6% CSNPs. Morphology images showed that increased CSNPs reduced the film&amp;rsquo;s amorphous character, especially in high level, in which higher CSNPs (8%) resulted in the aggregation of particles in the composites. The nano-reinforcement films showed higher thermal stability as compared to pure chicken skin gelatin films. In conclusion, the film with 6% CSNPs showed the best formulation, as it demonstrated high in TS, YM and Tm value, while low in EAB, water solubility and WVP value compared to other films. The results presented in this study showed the feasibility of using bio-nanocomposite technology to improve the properties of biopolymer films based on chicken skin gelatin.

Fish gelatin films laminated with emulsified gelatin film or poly(lactic) acid film: Properties and their use as bags for storage of fried salmon skin

Bilayer films based on fish gelatin films incorporated with epigallocatechin gallate (EGCG) and laminated with poly (lactic acid) film (PLAF) or emulsified gelatin film (EF) were fabricated by thermo-compression molding. Bilayer films showed good handling with low water vapor and oxygen permeabilities. The incorporation of 12 wt % EGCG promoted interactions of gelatin chains, as indicated by improved mechanical and UV–visible light barrier properties. These bilayer films were used for bag making, in which fried salmon skins (FSS) were packaged. After 30 days of storage, FSS packaged in bilayer bags prepared from gelatin films containing EGCG laminated with EF (EF/E-GF) had lower yellowish, peroxide value, thiobarbituric acid reactive substances value and volatile compounds. Overall likeness score as well as linoleic acid (C18:2 n-6) and linolenic acid (C18:3 n-3) contents were also higher than those of FSS packaged in the bags from gelatin films without and with EGCG laminated with PLAF (PLAF/GF and PLAF/E-GF). Therefore, EF/E-GF bilayer films could be used as active packaging for high lipid content foods, especially for fried fish skin, in which lipid oxidation could be retarded.

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations.

Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

Influence of anise (Pimpinella anisum L.) essential oil on the microbial, chemical, and sensory properties of chicken fillets wrapped with gelatin film.

The present study aimed to develop a novel active edible film based on gelatin incorporated with 0, 0.3, 0.6, and 0.9% w/w anise essential oil as a natural preservative and investigate the shelf life extension potential of chicken fillets during 12 days of refrigerated storage. The chicken fillets were wrapped with the essence-free and anise essential oil-loaded gelatin films, and microbial counts, chemical and sensory tests were surveyed during chilled storage. Results showed that aerobic mesophilic bacteria and Pseudomonas spp counts significantly decreased at all levels of anise essential oil during the first week of storage, while psychrotrophs, yeasts, and molds numbers began to reduce at concentrations of 0.6 and 0.9% from day 6. The using of anise essential oil caused a significant decrease of chemical parameters of chicken fillets, and the values of pH, peroxide, thiobarbituric acid reactive substance, and total volatile basic-nitrogen reached from 7.42, 5.7 meq/kg, 2.21 mg malondialdehyde/kg, and 24.94 mg N/100 g for the essence-free wrapped samples to 4.8, 6.35 meq/kg, 1.73 mg malondialdehyde/kg, and 18.78 mg N/100 g for the ones wrapped with 0.9% anise essential oil-loaded gelatin films at the end of storage day. In conclusion, application of gelatin films loaded with 0.6 and 0.9% anise essential oil can be advised for wrapping chicken fillets to prolong the shelf life for at least one week.

Intrinsic Color Sensing System Allows for Real-Time Observable Functional Changes on Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Stem-cell based in vitro differentiation for disease modeling offers great value to explore the molecular and functional underpinnings driving many types of cardiomyopathy and congenital heart diseases. Nevertheless, one major caveat in the application of in vitro differentiation of human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) involves the immature phenotype of the CMs. Most of the existing methods need complex apparatus and require laborious procedures in order to monitor the cardiac differentiation/maturation process and often result in cell death. Here we developed an intrinsic color sensing system utilizing a microgroove structural color methacrylated gelatin film, which allows us to monitor the cardiac differentiation process of hiPSC-derived cardiac progenitor cells in real time. Subsequently this system can be employed as an assay system to live monitor induced functional changes on hiPSC-CMs stemming from drug treatment, the effects of which are simply revealed through color diversity. Our research shows that early intervention of cardiac differentiation through simple physical cues can enhance cardiac differentiation and maturation to some extent. Our system also simplifies the previous complex experimental processes for evaluating the physiological effects of successful differentiation and drug treatment and lays a solid foundation for future transformational applications.

Characterization and Application of Gelatin Films with Pecan Walnut and Shell Extract (Carya illinoiensis).

Phenolic compounds that come from natural products are a good option for minimizing lipid oxidation. It should be noted that these are not only introduced directly into the food, but also incorporated into edible biofilms. In contact with food, they extend its useful life by avoiding contact with other surface and preventing deterioration air, one of the main objectives. In particular, gelatin is a biopolymer that has a great potential due to its abundance, low cost and good film-forming capacity. The aim of this study has been to design and analyse gelatin films that incorporate bioactive compounds that come from the walnut and a by-product, the walnut shell. The results showed that mechanical and water vapor barrier properties of the developed films varied depending on the concentration of the walnut, shell and synthetic antioxidant. With increasing walnut concentration (15%) the permeability to water vapor (0.414 g·mm/m2·day·Pascal, g·mm/m2·day·Pa) was significantly lower than the control (5.0368 g·mm/m2·day·Pa). Furthermore, in the new films the elongation at the break and Young’s modulus decrease by six times with respect to the control. Films with pure gelatin cannot act as an antioxidant shield to prevent food oxidation, but adding pecan walnut (15% concentration) presents 30% inhibition of the DPPH stable radical. Furthermore, in the DSC, the addition of walnut (15 and 9% concentrations), showed the formation of big crystals; which could improve the thermal stability of gelatin films. The use of new gelatin films has shown good protection against the oxidation of beef patties, increasing the useful lifetime up to nine days, compared to the control (3–4 days), which opens up a big field to the commercialization of meat products with lower quantities of synthetic products.

Release kinetics and antibacterial activity of potassium salts of iso-α-acids loaded into the films based on gelatin, carboxymethyl cellulose and their blends

The effect of increasing concentrations (0, 15, 30, and 60 mg/100g) of potassium salts of iso-α-acids (KIAA) on the release kinetics and antimicrobial activity of edible films based on gelatin (GEL), carboxymethyl cellulose (CMC) and their blends (75/25, 50/50, and 25/75) was investigated. Due to the phase separation, the GEL formed microspheres in the 50/50 and 25/75 mixtures. Release of KIAA from the GEL and CMC-rich films was primarily caused by swelling and dissolution, respectively. The pure GEL film offered at least 14 times slower release of KIAA compared to the polysaccharide carrier. The Weibull with Fmax and Gompertz models efficiently predicted the release behavior. The KIAA diffusion mechanism was found to be Quasi-Fickian. The KIAA-added carriers exhibited strong inhibitory effects on E. coli, L. monocytogenes, and S. aureus. The GEL100 system had the best antibacterial effectiveness, likely due to its low pH resulting in high concentration of the undissociated forms of KIAA.

Methods of incorporation of D-limonene microparticles in edible films

No presente trabalho, D-limoneno foi microencapsulado por gelificação iônica utilizando alginato e íons cálcio e foi aplicado na formulação de filmes comestíveis biodegradáveis de gelatina e quitosana. Foram avaliados três métodos de incorporação das micropartículas na solução filmogênica: agitação magnética, agitação de alta velocidade (Ultra-turrax) e sonicação. A morfologia das micropartículas e dos filmes foram avaliados por microscopia óptica e microscopia eletrônica de varredura (MEV). Além disso, nas micropartículas determinou-se a eficiência de encapsulação (EE) e o diâmetro médio e nos filmes as propriedades mecânicas e a permeabilidade ao vapor de água (PVA). As micropartículas de D-limoneno apresentaram formato esférico, diâmetro médio de 134,6 ?m e EE de 83,95%. A incorporação de micropartículas elevou a resistência à tração, o módulo de Young e a PVA e reduziu a elongação na ruptura dos filmes. Porém, considerando os métodos de incorporação estudados, não houve diferença significativa, sugerindo que um simples método como a agitação magnética foi suficiente para dispersar as micropartículas na solução filmogênica.

Quercetin loaded gelatin films with modulated release and tailored anti-oxidant, mechanical and swelling properties

Quercetin, a flavonoid widely diffused in fruits and vegetables, is known for its good pharmacological qualities, such as anti-oxidant and anti-inflammatory properties. In this work, we loaded quercetin on gelatin films with the aim to develop materials with tailored anti-oxidant, mechanical and stability properties. To this purpose, gelatin films at increasing flavonoid content were prepared using two different solvents, namely H2O/EtOH (EtOH films) and DMSO (DMSO films). Quercetin content increased up to about 3.8 and 1.8 wt% in DMSO and EtOH films, respectively. The use of DMSO as solvent prevents the partial regain of collagen triple helix structure during gelling of gelatin sols and results in remarkable extensibility of the films. At variance, EtOH films display X-ray diffraction patterns and DSC plots in agreement with the presence of triple helix structure, and exhibit reduced swelling and increasing mechanical properties on increasing quercetin content. Moreover, their values of denaturation enthalpy indicate the presence of chemical interaction between the flavonoid and gelatin, which can be responsible of their lower quercetin release in PBS in comparison to DMSO films. The flavonoid release is sustained for both series of films and occurs through anchorage to gelatin nanoparticles. Moreover, both DMSO and EtOH functionalized films exhibit relevant anti-oxidant properties, in agreement with their RSA levels, which are comparable to that of pure quercetin.