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1.
With the goal of improving the physico-chemical performance of fish gelatin-based films, composite films were prepared with increasing concentrations of chitosan (Ch) (100G:0Ch, 80G:20Ch, 70G:30Ch, 60G:40Ch and 0G:100Ch, gelatin:Ch), and some of their main physical and functional properties were characterised. The results indicated that the addition of Ch caused significant increase (p < 0.05) in the tensile strength (TS) and elastic modulus, leading to stronger films as compared with gelatin film, but significantly (p < 0.05) decreased the elongation at break. Ch drastically reduced the water vapour permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 60:40 ratio has been of about 50% (p < 0.05). The light barrier measurements present low values of transparency at 600 nm of the gelatin–chitosan films, indicating that films are very transparent while they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed a clear interaction between fish gelatin and Ch, forming a new material with enhanced mechanical properties.  相似文献   

2.
The effects of nanorod-rich zinc oxide (ZnO–nr) on the flow properties of bovine gelatin solution and on the sorption isotherm, antimicrobial, and physchochemical properties of gelatin films were investigated. ZnO–nr was incorporated into gelatin solutions at different concentrations (0.01, 0.02, 0.03, and 0.05 g/g dried gelatin). The introduction of low ZnO–nr concentrations (0.05 g/g dried gelatin) to gelatin solutions significantly increased the viscosity of the solution from 9 to 11.9 mPa s and decreased the permeability of the films to water vapor from 8.9 × 10−11 to 1.78 × 10−11 (g m−1 s−1 Pa−1). Solubility in water decreased from 30% to 20%, and monolayer water content of the films decreased from 0.13 to 0.10 (g water/g dried solid), whereas their contact angle increased from 45° to 85° with increasing ZnO–nr concentration from 0 to 0.05 g/g dried gelatin. The ZnO–nr gelatin films had very low UV transmittance and were able to absorb more than 50% of the near-infrared spectra. These films showed excellent antimicrobial activity against Staphylococcus aureus. These properties suggest that ZnO–nr can be potentially used as fillers in gelatin-based films for active packaging materials in the pharmaceutical and food packaging industries.  相似文献   

3.
The gelatin-based nanocomposite films (GNCFs) containing 0, 1, 3, and 5% zinc oxide nanoparticles (N-ZnO) and/or 0, 3, 5, and 10% chitin nanofibers (N-chitin) were prepared, and their water vapor permeability (WVP), chemical structure and microstructure, and their mechanical, thermal, and antifungal properties were investigated. Results showed that incorporation of N-ZnO improved WVP, mechanical, thermal, and antifungal properties of the gelatin-based films. Moreover, physicochemical and antifungal properties of the nanocomposite films improved by increasing N-ZnO concentration. However, applying N-chitin in gelatin films could not enhance barrier properties of the films against water vapor, probably due to the hydrophilic nature of N-chitin. On the other hand, tensile strength of the GNCFs containing N-chitin increased by an increase in nanoparticle concentration, up to 5%, Incorporation of N-chitin in the gelatin film raised both thermal stability and antifungal activity. Simultaneous incorporation of chitin and ZnO nanoparticles in the GNCFs had the interactive effect on improving the physicochemical and antimicrobial properties of GNCFs. For instance, thermograms of differential scanning calorimetry (DSC) showed that the GNCF containing both nanoparticles increased melting point and ?H m in comparison with net gelatin film. Furthermore, thermograms of thermogravimetric analysis (TGA) indicated that applying both of nanoparticles in gelatin films led to higher thermal stability of polymer against decomposition at higher temperatures, compared to the gelatin film containing each of them.  相似文献   

4.
The utilization of petroleum-derived synthetic materials causes severe ecological problems, such as environmental pollution and soil degradation. Hence, using naturally derived and renewable materials to fabricate novel biodegradable films for safe and effective food packaging has been a subject of interest over the years. Here, the novel antimicrobial and controlled biodegradable gelatin-based edible films were developed using nisin as the antimicrobial agent, amino-functionalized montmorillonite as the nanoparticle filler, and dialdehyde xanthan gum as the crosslinking agent. The results indicate that the ultraviolet barrier ability, water resistance, and mechanical properties of gelatin-based edible films are obviously improved on account of the crosslinking effect. Moreover, the resulting films demonstrate antimicrobial activity against Staphylococcus aureus owning to the addition of nisin. Furthermore, the crosslinking can slow down the erosion of the edible films by fungi due to the improved hydrophobicity and compact structure. Particularly, the edible films can be completely biodegraded in soil within 30 days. Meanwhile, the rate of soil biodegradation can be well controlled by adjusting the crosslinking degree. Overall, this novel gelatin-based edible films have potential applications in food packaging.  相似文献   

5.
Gelatin film from blue shark (Prionace glauca) skin was investigated in order to utilize what is one of the most serious marine wastes in Japan. Film properties from shark skin such as tensile strength (TS), elongation at break (EAB) were evaluated. The TS of gelatin film from shark skin was affected by the protein concentration (1, 2 and 3%) of the film-forming solution (FFS). TS of the film from a 2% protein FFS was the highest. EAB and water vapor permeability (WVP) increased with increasing FFS protein concentration. WVP of shark skin gelatin was evidently low as compared to gelatin films from other fish. An increase in the FFS protein concentration decreased transparency at almost all wavelengths. Furthermore, opacity at 280 nm was characteristically high as compared to films from bony fish skin. The addition of glycerol improved flexibility and enhanced the UV barrier property at 280 nm. However, transparency at the visible range and WVP increased with increasing glycerol content.From the above, it was suggested that shark skin gelatin film technology can be applied to pharmaceutical products or rich-fat food due to its excellent water and UV barrier properties.  相似文献   

6.
A commercial low-gelling fish skin gelatin was used to prepare edible films by casting with glycerol and sorbitol added as plasticizers. In order to improve the extremely low water resistance of gelatin films, composite films were prepared with increasing concentrations (wt/wt) of lignosulphonate (LS) from eucalyptus wood (100:0, 85:15, 80:20, 75:25, 70:30 and 65:35, gelatin:LS). How gelatin film properties were affected by the different types of gelatin and LS was determined by comparing bovine gelatin and three different LS (Ca2+, Mg2+ and Na+) in a mixture ratio of 80:20. Physical properties of films were characterized in terms of tensile strength, elongation at break, water solubility, water vapour permeability and opacity. Dynamic oscillatory tests of film-forming solutions revealed strong LS interference with the cold-renaturation ability of gelatin. LS ratios equal to or higher than the 80:20 blend interfered with intermolecular aggregation of gelatin helices. Supposedly, LS acted as a filler, inducing mostly nonbonding interactions with gelatin, as deduced from Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) studies. Lignosulphonate significantly reduced the elongation at break of fish gelatin films, water solubility being drastically reduced with a mixture ratio of 80:20 or higher. The water solubility of bovine gelatin-LS composite films was significantly lower than that for fish gelatin, regardless of the type of LS employed. For potential food packaging applications, the three LS were characterized in terms of cytotoxicity, radical scavenging capacity (DPPH assay) and antimicrobial capacity. The effective antioxidant levels (IC50: 83.4-97.5 μg/mL) were noticeably lower than the cytotoxic ones (IC50: 1480-1745 μg/mL), indicating that these compounds could be used as antioxidants at non-cytotoxic concentrations. No relationship between antioxidant and antimicrobial properties could be observed, the only notable antimicrobial finding being some activity against yeasts.  相似文献   

7.
The aim of this study was to determine the properties of gelatin films incorporated with thymol. Gelatin films were prepared from gelatin solutions (10% w/v) containing thymol (1, 2, 4, and 8% w/w), glycerol (25% w/w) as plasticizer, and glutaraldehyde (2% w/w) as cross‐linker. Cross‐likened films showed higher tensile strength, higher elongation at break, lower Young's modulus, lower water solubility, lower swelling, lower water uptake, and lower water vapor permeability. Incorporation of thymol caused a significant decrease in tensile strength, increase in elongation at break, decrease in Young's modulus, increase in water solubility, decrease in swelling and water uptake, and increase in water vapor permeability slightly. The films incorporated with thymol exhibited excellent antioxidant and antibacterial properties. The antibacterial activity of the films containing thymol was greatest against Staphylucoccus aureus followed by Bacillus subtilis followed by Escherichia coli and then by Pseudomonas aeruginosa. Thus, gelatin films‐containing thymol can be used as safe and effective source of natural antioxidant and antimicrobial agents with the purpose of evaluating their potential use as modern nano wound dressing. Practical Application : This study clearly demonstrates the potential of gelatin films incorporated with thymol as natural antioxidant and antimicrobial nano film. Such antimicrobial films exhibited excellent mechanical, physical, and water activities and could be used as antibacterial nano wound dressing against wounds burn pathogens.  相似文献   

8.
Gelatin films were prepared from gelatin solutions (10% w/v) containing Zataria multiflora essential oil (ZMO, 2, 4, 6 and 8% w/w of gelatin). Scanning electron microscopy observations indicate that ZMO droplets were well dispersed in the film matrix. Water solubility, water swelling, water uptake, water vapor permeability, tensile strength, elongation at break and Young's modulus for gelatin films were 27 ± 0.8%, 391 ± 11%, 135 ± 5%, 0.22 ± 0.014 g mm/m2 kPa h, 4.4 ± 0.4 MPa, 125 ± 7% and 8.8 ± 0.4 MPa, respectively. Incorporation of ZMO into gelatin films caused a significant decrease in swelling and water uptake and increase in solubility and water vapor permeability, a significant decrease in tensile strength, increase in elongation at break, decrease in Young's modulus of the films, dose-dependently. Gelatin/ZMO showed UV–visible light absorbance/transmission ranging from 280 to 480 nm with maximum absorbance at 420 nm. Gelatin films exhibited very low antioxidant activity while, gelatin/ZMO films exhibited excellent antioxidant properties. The gelatin/ZMO films also exhibited excellent antibacterial properties against both Gram-positive and Gram-negative bacteria. Our results suggested that the gelatin/ZMO films could be used as an active film due to its excellent antioxidant and antimicrobial properties for food packaging applications.  相似文献   

9.
Physical, chemical and antimicrobial properties of fish gelatin films with different concentrations of ethyl lauroyl arginate (LAE) were studied. Optical properties of film-forming solution did not vary with increased LAE content. However, pH and surface tension increased. The incorporation of LAE into the formulation increased moisture and solubility of the films. In addition, the presence of LAE affected mechanical properties, making films stronger and more flexible; it had no effect on water vapour permeability. Finally, films with LAE significantly increased antimicrobial properties against Listeria innocua, Shewanella putrefaciens and Pseudomonas fluorescens, but not against Aeromonas hydrophila. These antimicrobial films could be used as an alternative technology for extending shelf-life of fresh fish products.  相似文献   

10.
Waxy corn starch (amylopectin) and three of its chemical derivatives: acetylated cross‐linked (ACLS), oxidized (OS), and octenyl‐succinylated (OSA), were used together with additives such as Tween 80, sorbitol, and beeswax suspension or safflower oil to test their effect on film‐forming solutions (FFS) and films. The objectives of this study were the starch structure characterization, and its correlation with rheological properties of FFS and solubility, opacity, and water vapor permeability (WVP) of the produced films. Analysis of starch structure, rheological characterization, and films micrographs revealed that the starches contained predominantly low MW amylopectin molecules and film properties depended on their ability to reorganize. Additionally, the interaction among groups introduced in modified starches or with additive molecules can hinder or promote starch reorganization, resulting in films with increased or reduced WVP, solubility and transparency properties. Films were obtained by casting and showed a thickness less than 41 µm. Films prepared with OS and beeswax exhibited the best reorganizing capacity of FFS, resulting in less soluble (30.0 ± 1.6%), highly transparent (23.2 ± 3.3 UA × nm) and less permeable films (0.485 ± 0.016 g · mm · m−2 · h−1 · kPa−1). On the other hand, ACLS showed an opposite trend which was attributed to a more open film structure. These results contribute to understand the molecular interactions of waxy starch molecules in FFS which may be useful to design tailored coatings.  相似文献   

11.
Understanding the release kinetics of antimicrobials from polymer films is important in the design of effective antimicrobial packaging films. The release kinetics of nisin (30 mg/film) from chitosan–alginate polyelectric complex films prepared using various fractions of alginate (33%, 50%, and 66%) was investigated into an aqueous release medium. Films containing higher alginate fractions showed significantly lower (P < 0.05) degree of swelling in water. Total amount of nisin released from films into an aqueous system decreased significantly (P < 0.05) with an increase in alginate concentration. The mechanism of diffusion of nisin from all films was found to be Fickian, and diffusion coefficients varied from 0.872 × 10?9 to 8.034 ×10?9 cm2/s. Strong complexation was confirmed between chitosan and alginate polymers within the films using isothermal titration calorimetry and viscosity studies, which affects swelling of films and subsequent nisin release. Complexation was also confirmed between nisin and alginate, which limited the amount of free nisin available for diffusion from films. These low‐swelling biopolymer complexes have potential to be used as antimicrobial packaging films with sustained nisin release characteristics.  相似文献   

12.
This study investigated the effects of adding different concentrations of virgin coconut oil (VCO) on the optical, mechanical, thermodynamic and antimicrobial properties, as well as water vapour permeability and morphology of potato starch-based biodegradable films. Increasing VCO concentrations caused a rise in the light transmittance of the films from 2.13 to 4.79 mm−1 and a decrease in water vapour transmittance from 6.77 to 2.12 (10−5 GPa−1 h−1 m−1). At a VCO concentration of 14 wt% (based on potato starch), the tensile strength reached its highest value (19.98 MPa). Scanning electron microscopy showed that the surface of the film became smoother as VCO concentration increased. The addition of VCO inhibited the growth of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. In conclusion, VCO supplementation improved the mechanical, antibacterial and water barrier properties of starch-based films. These results could expand the scope of the application of starch-based films in food packaging.  相似文献   

13.
A new gelatin-protocatechuic acid (PCA) film with Escherichia coli O157:H7 phage JN01 was developed and characterised. After incorporated with JN01, swelling value, water vapour permeability, water solubility and elongation at break of gelatin-PCA film were not significantly different. The addition of JN01 increased b value and transparency of film, while it decreased L value, a value and tensile strength of film. Moreover, the gelatin-PCA-JN01 film presented antioxidant activity of 60.07%. Furthermore, JN01 could be steadily released from gelatin-JN01 and gelatin-PCA-JN01 films in aqueous solution, and their release rates were 7.56% and 0.12% after 11 h, respectively. The microstructure analysis showed that JN01 particles were clustered and uniformly distributed in film, and the aggregation would be attenuated in the presence of PCA. Meanwhile, E. coli O157:H7 counts were 1.13 log10CFU mL−1 and 0.45 log10CFU mL−1 lower in gelatin-JN01 and gelatin-PCA-JN01 films compared with pure gelatin film in vitro at 4 °C for 24 h, respectively. After stored at 4 °C for 7 days, Escherichia coli O157:H7 counts were 1.00 log10CFU g−1 and 0.80 log10CFU g−1 lower in beef packed with these two gelatin films, compared with beef without gelatin film, respectively. In conclusion, the developed gelatin-PCA-JN01 film has potential application in food preservation.  相似文献   

14.
Beef gelatin, in combination with varying levels of glycerol, was used to manufacture films by extrusion. A twin-screw co-rotating extruder was employed to produce the films and the mechanical and barrier properties of the films were investigated. Increasing the plasticizer content increased (P < 0.05) elongation at break (EAB) values but decreased (P < 0.05) tensile strength (TS) values. Oxygen permeability (OP) values for gelatin-based composite films increased (P < 0.05) as the concentration of glycerol increased. Additionally, the solubility of films in water and seal strength increased as glycerol content increased. FTIR results indicated that increasing glycerol concentration increased and displaced the peak situated around 1032 cm−1, which corresponded to glycerol. Gelatin-based composite films with a concentration of 0.2% glycerol possessed the lowest water vapor permeability (WVP) and OP values. From the data generated in this study, it is clear that the use of a plasticizing agent in film formulations should be carefully considered because of the negative effects that the plasticizing agent could have on extruded film barrier properties.  相似文献   

15.
In this study, ethylcellulose/hydroxypropylmethylcellulose/ethylcellulose (EC/HPMC/EC) three-layer films including Nisaplin® or nisin and lecithins were formulated. Lecithins were used as plasticizers to ensure cohesion between hydrophobic ethylcellulose and hydrophilic HPMC layers. It was observed that the introduction of pure nisin or its non-pure commercial form Nisaplin® into films didn't significantly alter their mechanical and optical properties. Additionally, these nisin or Nisaplin-loaded multilayer films showed significant antimicrobial activity. The comparison of inhibition diameters obtained with EC/HPMC film used as control and EC/HPMC/EC films demonstrated that the three-layer films delayed nisin desorption. This was confirmed by the kinetics of nisin release in a (0.8% w/v) NaCl solution at 28 °C: nisin from two-layer EC/HPMC films totally desorbed within 0.5 h, while the three-layer films allowed to expand nisin release time over 20 h. The ratio of nisin desorption coefficients (kd): kd (EC/HPMC)/kd (EC/HPMC/EC) was determined after desorption modelling, and was found to be up to 118, proving that multilayer films with hydrophobic layers could be a potential way to control nisin release from antimicrobial bio-packagings.Industrial relevanceThis paper concerns active packaging, considered as a new approach to preserve food shelf life. Active packaging is a real gain for plastic and food industrials. Coating was used to obtain antimicrobial packaging. The impact of incorporating the antimicrobial agent in multilayer films on the release kinetics is investigated.  相似文献   

16.
Antimicrobial activity is an attractive property for packaging materials which can extend the shelf life of products and provide microbial safety for consumers. The study aimed to analyze the physicochemical and antimicrobial properties of gelatin-based edible films containing trans-anethole as the active additive. Encapsulation with β-cyclodextrin was used as an effective way to introduce trans-anethole into gelatin matrix. The results showed that the trans-anethole/β-cyclodextrin inclusion complex could be evenly dispersed in the gelatin-based edible films with appropriate addition. The incorporation of trans-anethole conferred the edible films with good antimicrobial activity as expected, which increased with the content of trans-anethole increasing. Moreover, the addition of inclusion complex improved the tensile strength and surface hydrophobicity and reduced the moisture content of the edible films. It was interesting that the edible films presented great UV light barrier property and it was increased by the addition of inclusion complex. Overall, the antimicrobial gelatin-based edible films showed great potential as bioactive packaging materials to extend food shelf life.  相似文献   

17.
In order to provide gelatin films with antioxidant capacity, two sulphur-free water-insoluble lignin powders (L1000 and L2400) were blended with a commercial fish-skin gelatin from warm water species at a rate of 85% gelatin: 15% lignin (w/w) (G–L1000 and G–L2400), using a mixture of glycerol and sorbitol as plasticizers. The water soluble fractions of G–L1000 and G–L2400 films were 39.38 ± 1.73% and 46.52 ± 1.66% respectively, rendering radical scavenging capacity (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, ABTS assay)) of 27.82 ± 2.19 and 15.31 ± 0.88 mg vitamin C equivalents/g film, and ferric ion reducing ability (FRAP assay) of 258.97 ± 8.83 and 180.20 ± 5.71 μmol Fe2+ equivalents/g film, respectively. Dynamic oscillatory test on film-forming solutions and Attenuated Total Reflectance (ATR)-FTIR spectroscopy study on films revealed strong lignin-induced protein conformational changes, producing a noticeable plasticizing effect on composite films, as deduced from the study of mechanical (traction and puncture tests) and thermal properties (Differential Scanning Calorimetry, DSC). The gelatin films lose their typical transparent and colourless appearance by blending with lignin; however, the resulting composite films gained in light barrier properties, which could be of interest in certain food applications for preventing ultraviolet-induced lipid oxidation. Lignin proved to be an efficient antioxidant at non-cytotoxic concentrations, however, no remarkable antimicrobial capacity was found.  相似文献   

18.
Jang Woo Park  Seung Yong Cho 《LWT》2008,41(4):692-700
Gelatin-based edible films were produced by extruding hot melt of gelatin-based resins through a die with slot orifice and followed by heat-pressed method. The resins were plasticized with glycerol, sorbitol and the mixture of glycerol and sorbitol (MGS). The effect of type of plasticizer on extruded and heat-pressed (EHP) film-forming capacity was studied, and the mechanical and water barrier properties of resulting EHP gelatin films were compared with those of gelatin films prepared by solution casting method. Stretchable films were formed when glycerol or MGS were used as plasticizer, whereas resins plasticized with sorbitol were extruded in non-stretchable sheets. Glycerol plasticized gelatin film showed the highest flexibility and transparency among the EHP films tested. Tensile strength (TS), elongation (E) and water vapor permeability (WVP) of glycerol plasticized EHP gelatin films were 17.3 MPa, 215.9% and 2.46 ng m/m2 s Pa, respectively, and EHP gelatin films had higher E values, lower TS values and higher WVP values compared to the glycerol plasticized cast gelatin films.  相似文献   

19.
Polyethylene-based films coated with nisin loaded HPMC films were put in contact with food simulants, i.e. agarose gels with 5 or 30% (w/w) fat. Nisin desorption from the multi-layer films and diffusion in agarose gels were monitored by ELISA (Enzyme Linked ImmunoSorbent Assay). The data obtained after 2 or 6 days of contact between antimicrobial films and agarose gels were employed to determine nisin mass transfer by numerical modeling following Fick's second law. The values were in the range from 0.87 × 10? 3 m s? 1 to 4.30 × 10? 3 m s? 1 and 6.5 × 10? 11 m2 s? 1 to 3.3 × 10? 10 m2 s? 1, for nisin apparent desorption and diffusion coefficients, respectively. The diffusion process was governed by interactions between food matrix simulant and nisin. Moreover, it was observed that the polymer in the coating did not modify plastic film initial mechanical resistance and water vapor permeability.Industrial relevanceThis paper concerns active packaging, considered as a new approach to preserve food shelf life. Active packaging is a real gain for plastic and Food industrials. The paper deals with coating as a manner to activate packaging. The impact of coating on film properties is investigated.Also, predictive models are proposed to determine antimicrobial agent desorption and diffusion during some storage conditions.  相似文献   

20.
We have investigated the antioxidant properties (FRAP ferric-reducing ability and ABTS radical-scavenging capacity) as well as the light barrier properties of gelatin-based edible films containing oregano or rosemary aqueous extracts. For comparative purposes both bovine-hide and tuna-skin gelatins were studied. The oregano and rosemary extracts were first characterised by both their total phenolic content and antioxidant activity, with the oregano extract showing the higher values. HPLC and confocal laser scanning microscopy revealed qualitative differences between extracts although rosmarinic acid was the most abundant phenolic compound in both. After determining the total quantities of phenolics on films, the polyphenol–protein interaction was found to be more extensive when tuna-skin gelatin was employed. However, this did not clearly affect the antioxidant properties of the films, although it could affect the phenol diffusion from film to food. The light barrier properties were improved by the addition of oregano or rosemary extracts, irrespective of the type of gelatin employed.  相似文献   

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