Mechanical Properties Of Edible Films Research Articles

Production and characterization of chitosan-gelatin nanofibers by nozzle-less electrospinning and their application to enhance edible film’s properties

Abstract In this study nozzle-less electrospinning device has been introduced as a promising technology to produce food grade nanofibers with high production yield in comparison to nozzle based instrument. Electrospinning was set up with pure gelatin solutions and different volume ratios of chitosan to gelatin. SEM images showed that by increasing volume ratio of chitosan to gelatin a decrease in fiber diameter could be observed. The thinnest nanofibers had mean diameter of 96.26 ± 34.44 nm. DSC analysis indicated that thermal resistance of the nanofiber was higher than pure ingredients. ATR-FTIR analysis showed that the main peaks of ingredients can be detected in spectrum of produced nanofibers. The optimum nanofibers were used to enhance physical properties of edible gluten film. Nanofiber treated edible film had lower water vapor permeability and better mechanical properties in comparison to blank sample. The maximum force of the edible film containing 2 mg/cm2 nanofibers that could tolerate was 3.12 N and for blank edible film without nanofibers was 0.58 N. The results of this study indicated that nozzle-less electrospinning can be applied as a new method for production of nanofibers in large scale which can be further applied for enhancement of mechanical properties of edible films.

Development and characterization of the mechanical properties of edible film from ginger starch, chitosan with glycerin as plasticizer to food packaging

Packaging used edible film is one of the food preservation techniques. Many studies have proven that edible films can extend the shelf life and improve the quality of food products. Edible film from ginger starch and chitosan with glycerin as plasticizer has been successfully prepared and characterized. The purpose of this research was to produce and characterized of the mechanical properties of edible film from ginger starch, chitosan, and glycerin as plasticizer. Edible film was characterized by UTM, TGA, FTIR and Water Uptake Test. The results of tensile strength test of edible film is 0.67125 MPa and elongation up to 15.67%. The thermal degradation of material reached 176.9695°C, water uptake of edible film up to 2.5%, and FTIR data shows an interaction between ginger starch, chitosan, and glycerin. It concluded that edible film from ginger starch, chitosan, and glycerin as plasticizer has good mechanical properties and has potential as a packaging.

Development and physicochemical, thermal and mechanical properties of edible films based on pumpkin, lentil and quinoa starches

Starches isolated from pumpkin fruits, lentil and quinoa seeds were used to prepare edible films. Physicochemical, thermal and mechanical properties of films were determined and compared with potato-based starch (PS) film. It was found that botanical origin of starch has a crucial effect on the films properties. The much lower solubility and higher swelling capacity compared to PS film exhibited lentil and pumpkin starch-based films, respectively. All of the films exhibited significantly higher water vapor permeability compared to PS one. Tensile strength and elongation at break of the films varied between 8.98 and 13.85 MPa, and 3.35 to 4.44%, respectively. All of the films acted as a solid-like materials with prevalently elastic behavior and exhibited endothermic peaks in DSC measurement in the range of 249–281 °C, referred to the melting of films. This study demonstrated that starches from non-conventional sources are good alternative to conventional to develop edible films.

Interaction Between Caseinate and Carrageenans Results in Different Physical and Mechanical Properties of Edible Films

Abstract Edible films were elaborated with sodium caseinate and different types of carrageenans (iota, kappa or lambda), and glycerol as plasticizer, to determine the different specific interactions between caseinate and carrageenans on physical and mechanical properties via a response surface methodology approach. The different sulphate groups content in the different carrageenans affected differentially edible films properties. The use of lambda carrageenan in edible film formulation resulted in more soluble and permeably film, with a concomitantly both less rigid and more elastic structure. The edible film formulation was optimized to 8.0 % of caseinate, 0.4% of carrageenan (irrespectively of the type) and 0.3% of glycerol.

A biodegradable and edible packaging film based on papaya puree, gelatin, and defatted soy protein

Abstract Study of physical and mechanical properties of edible films produced out of various blends of papaya puree (PP), gelatin (G) and defatted soy protein (DSP). Film forming solutions at different levels of papaya puree, gelatin and defatted soy protein were prepared and the films were cast at room temperature. The results of this study indicated, with the addition of gelatin to the papaya puree, the films had shown significant increase (P g = 121.81 ± 0.20 a °C, T m = 174.59 ± 0.52 a ° C and ΔH = 220.76 ± 0.36 a J/g). The analysis of blended papaya films by fourier transforms infrared spectra revealed significant compatibility of papaya puree, gelatin and defatted soy protein and their influence on optical, mechanical, barrier and structural properties. Thus, based on these observations, the papaya blended films could be effectively used as primary packaging material in near future.

Design and characterization of spice fused tamarind starch edible packaging films

Abstract The main aim of this study was to produce and optimize spice fused tamarind seed starch edible films for meat packaging. Among fourteen different spices examined for incorporation with tamarind starch edible films, ball milled Syzygiumaromaticum and Cinnamomum cassia were selected because of its high preservative properties. Ball milled spices were found to have break point for release of active compounds. Break point sample of S. aromaticum was found to have high antioxidant property with total phenolic content of 29.31 ± 0.31 mg GAE/g. Break point sample of C. cassia was found to have high antibacterial activity against a panel of food pathogenic and meat putrefying bacteria. Edible films prepared from tamarind seed starch were studied for its mechanical properties. Artificial Neural Network (ANN) model was developed for prediction of mechanical properties of edible film using central composite design experimental data. Examined model of Probabilistic neural network was found to be fit for experimental data with average correlation coefficient (R2) of 0.989. Minimum inhibitory concentration mixture of S. aromaticum and C. cassia was supplemented with optimized edible film mixture and improvement in antioxidant and antibacterial properties of edible films were observed.

Study the Physicochemical, Antimicrobial and Mechanical Properties of Edible Films Based on Cassava Starch Enriched with Extracts of Fenugreek

In this study, in order to produce and examine the properties of enriched cassava starch films, fenugreek extract in ratios of 15%, 25%, 35% and 40% plasticizer added to 4 grams of cassava starch and starch films were prepared by Kasting under controlled conditions. Mechanical testing of cassava starch films containing fenugreek extract showed that the tensile strength decreased from 28.94 to 24.97 (MPa), percent of elongation increased from 32.12 to 36.42 and Young's modulus significantly decreased from 1012.24 to 789.76 (MPa). For cassava starch films containing fenugreek extract, permeability to water vapor increased from 7.25 to 10.51 (g/m.s.pa10−7) and permeability to oxygen increased from 5.20 to 7.10. Cassava starch films containing fenugreek extract water uptake, increased with increasing concentration. Examine the color parameters showed that transparency increased from 95/59 to 95/29and satiety of color index with increasing concentration, increased from 1.30 to 1.32. No new peaks were observed in spectrophotometric infrared spectra. Therefore, fenugreek extract without significant changes in the public properties of cassava starch can be used as active packaging in edible coatings and packaging of food and agricultural products.

Structural and mechanical properties of edible films made from native and modified cush-cush yam and cassava starch

Several different hydrocolloids, such as starch, have been proposed as suitable base materials (matrices) for edible films in food packaging. Edible films from native and modified starch plasticized with glycerol were developed. Starches were obtained from dark cush-cush yam (Dioscorea trifida) and cassava (Manihot esculenta C.) from Venezuela, and chemically modified by cross-linking with sodium trimetaphosphate. The uniaxial tensile, microstructural and barrier properties of the films were then evaluated to determine their potential as a replacement for existing synthetic materials used in the food industry. The structure of the materials showed that the gelatinization process of cush-cush yam films was poorer than that of cassava. The glycerol–starch interaction (glycerol-amylose) was stronger in the films composed of modified starches and was more marked in cassava based films. All the films studied exhibited promising mechanical properties, with those derived from cush-cush yams showing the highest Young's modulus and resistivity values. Cassava based edible films and films derived from modified starch from both sources showed maximum flexibility, reinforcing the idea that the glycerol–starch interactions are stronger in these materials. Crosslinked films tended to be more permeable to water vapor due to their hydrophilic characteristics. The properties observed in these biodegradable materials highlight their potential as food packaging materials, thus enabling the replacement of synthetic materials that contaminate the environment.

Effect of Maillard reaction products on the physical and antimicrobial properties of edible films based on ε‐polylysine and chitosan

Edible films based on Maillard reaction products (MRPs) of ε-polylysine and chitosan, without the use of any plasticiser, were prepared by solution casting. The effect of Maillard reaction parameters (reaction time and the ratio of polylysine/chitosan) of ε-polylysine and chitosan on the structure, moisture content, water solubility, total colour difference and mechanical properties of edible films formed by MRPs were systematically evaluated. Scanning electron microscopy confirmed that edible films prepared by the MRPs of ε-polylysine and chitosan through the Maillard reaction exhibited a more compact and dense structure than those from the mixture of biopolymers without the presence of MRPs. The tensile strength and % elongation values of films from the mixture were decreased significantly with the rise of ε-polylysine (P < 0.05). The moisture content of the films was not significantly affected by Maillard reaction, whereas water solubility was decreased and total colour difference was increased significantly (P < 0.05) with the extension of Maillard reaction time. In addition, antimicrobial activity of chitosan films against E. coli and S. aureus. could be achieved by incorporating ε-polylysine into chitosan. These films can ensure food quality and safety, especially for coating highly perishable foods, such as meat products. © 2014 Society of Chemical Industry.

Effects of Interactions between the Constituents of Chitosan-Edible Films on Their Physical Properties

The main objective of this work was to evaluate the effect of chitosan and plasticizer concentrations and oil presence on the physical and mechanical properties of edible films. The effect of the film constituents and their in-between interactions were studied through the evaluation of permeability, opacity and mechanical properties. The effects of the studied variables (concentrations of chitosan, plasticizer and oil) were analysed according to a 23 factorial design. Pareto charts were used to identify the most significant factors in the studied properties (water vapour, oxygen and carbon dioxide permeability; opacity; tensile strength; elongation at break and Young’s modulus). When addressing the influence of the interactions between the films’ constituents on the properties above, results show that chitosan and plasticizer concentrations are the most significant factors affecting most of the studied properties, while oil incorporation has shown to be of a great importance in the particular case of transport properties (gas permeability), essentially due to its hydrophobicity. Water vapour permeability values (ranging from 1.62 × 10−11 to 4.24 × 10−11 g m−1 s−1 Pa−1) were half of those reported for cellophane films. Also the mechanical properties (tensile strength values from 0.43 to 13.72 MPa and elongation-at-break values from 58.62% to 166.70%) were in the range of those reported for LDPE and HDPE. Based on these results, we recommend the use of 1.5% (w/w) chitosan concentration to produce films, where the oil and plasticizer proportions will have to be adjusted in a case-by-case basis according to the use intended for the material. This work provides a useful guide to the formulation of chitosan-based film-forming solutions for food packaging applications.

Starch–gelatin edible films: Water vapor permeability and mechanical properties as affected by plasticizers

Physical and mechanical properties of edible films based on blends of sago starch and fish gelatin plasticized with glycerol or sorbitol (25%, w/w) were investigated. Film forming solutions of different ratios of sago starch to fish gelatin (1:0, 2:1, 3:1, 4:1, and 5:1) were used and cast at room temperature. Amylose content of sago starch was between 32 and 34% and the protein content of the fish gelatin was found to be 81.3%. The findings of this study showed that the addition of fish gelatin in starch solutions has a significant effect ( p < 0.05), resulting in films with lower tensile strength (TS) and higher water vapor permeability (WVP). On the other hand, increasing protein content (from 10.9% to 21.6%) in film samples plasticized with sorbitol showed significantly lower ( p < 0.05) TS but no trend was observed in % elongation-at-break (EAB) and no differences in WVP. However, TS decreased with higher protein content in the samples when either plasticizers were used in general, but no significance differences was observed among the samples ( p < 0.05) with glycerol with exception to film with high protein content (21.6%) only and no trend was observed in % EAB among samples as well. Significant difference ( p < 0.05) was observed in TS and viscosity between different formulations with sorbitol. The morphology study of the sago starch/fish gelatin films showed smoother surfaces with decreasing protein in the samples with either plasticizer. DSC scans showed that plasticizers and protein content incorporated with sago starch films reduced the glass transition temperature ( T g) and melting temperature ( T m) and the melting enthalpy (Δ H m). In this study, observation of a single T g is an indication of the compatibility of the sago starch and fish gelatin polymers to form films at the concentration levels used.

Stability of the mechanical properties of edible films based on whey protein isolate during storage at different relative humidity

Formulations for whey protein isolate (WPI)-based films include low molecular weight plasticizers, which implies certain degree of instability of films properties due to plasticizer migration. The aim of this work was to study the effect of storage time on the mechanical properties of WPI films plasticized with two low molecular weight polyols: glycerol (Gly) and sorbitol (Sor). Films were stored inside cabins at 50% or 75% relative humidity (RH) and at room temperature. Mechanical properties and moisture content were measured at regular intervals for 30 weeks. The effect of plasticizer type and content and RH on mechanical properties right after equilibrium (1 week) was also included in this study. After equilibrium, Gly was found to be a more efficient plasticizer than Sor. Films plasticized with Gly were found to be more flexible and weaker and to have higher moisture content than films with the same amount of Sor. There was a saturation value for plasticizer content (40% for Gly and 50% for Sor), above which the film became weaker, but not more flexible. Storage time did not affect either the appearance or the mechanical properties of films plasticized with Gly. However, films plasticized with Sor became harder and less flexible with time likely due to Sor crystallization.

Mechanical properties of tapioca-starch edible films containing sorbates

The effect of sorbate present on mechanical properties of edible films prepared with suspensions of tapioca starch containing glycerol, was studied. Films were prepared by casting the systems after gelatinization. The storage modulus (E′) and the tangent of the phase angle (tanδ) of the film pieces were determined with a Dynamic Mechanical Thermal Analyzer along 8 weeks of storage at a relative humidity (RH) of 57.5% and at 25°C. Stress–strain behavior along quasi-static tests was also analysed using the same device. Results obtained showed that sorbate incorporation resulted in a decrease (≅75%) of E′ and an increase (≅200%) of tanδ after 2 weeks of storage. Antimicrobial presence also affected film performance along storage: it showed a continuous decrease of tanδ along 8 weeks storage as well as an increase in the tendency to rupture with time. Films without sorbate showed an increase of tanδ along 4 weeks and they presented rupture for all storage periods studied. Aging of starch, characteristics of the network as well as sorbate destruction along storage, are responsible for the changes observed in mechanical properties of the film along 8 weeks.

Combined Effects of Proteins and Polysaccharides on Physical Properties of Whey Protein Concentrate‐based Edible Films

ABSTRACT: The water‐vapor permeability (WVP) and mechanical properties of edible films formed from dry blends or co‐dried preparations of protein‐polysaccharide powders prepared from whey protein concentrate (WPC)‐45 and alginate, pectin, carrageenan, or konjac flour (WPC‐45‐to‐polysaccharide ratio of 95:5 w/w) were investigated. Films were prepared from 8% WPC using WPC‐45 (45% protein powder), consisting of 17.76 g of WPC‐45 in 82.84 g of water per 100 g solution to give 8% protein w/w. Films formed from co‐dried powders had lower WVP and higher tensile strength (TS), elastic modulus (EM) (P &lt; 0.05), and elongation (EL) than equivalent films formed from the dry blended powders. Films containing alginate had lower WVP and higher TS, EM, and EL than films containing pectin, carrageenan, or konjac flour. There is potential to alter the physical properties of hydrophilic films by combining whey protein and polysaccharide components.

Edible films made from gelatin, soluble starch and polyols, Part 3

The thermal and mechanical properties of edible films based on blends of gelatin with soluble starch plasticized with water, glycerol or sugars were investigated. Two different methods, known as ‘the high temperature’ and ‘the low temperature’ methods, consisting of casting aqueous solutions of blends at 60 and 20 °C, respectively, were employed for the preparation of films. With increasing water, glycerol or sorbitol content, a drop of elasticity modulus and tensile strength (up to 50% of the original values for 30% plasticizer) was observed. The tensile strength and percentage elongation increased with high gelatin contents (> 20% w w ). The development of a higher percentage renaturation of gelatin (reaching 70% for 5% water content) by the ‘low temperature’ method caused a reduction in gas and water permeabilities. The former decreased by one or two orders of magnitude for O 2 and CO 2, respectively. The semi-empirical model for calculation of gas permeability and the semi empirical equations for upper and lower limits of tensile moduli of composites were applied with limited success and the obtained values were compared to those experimentally determined.

Mechanical Properties and Water Vapor Permeability of Edible Films from Whey Protein Isolate andN-Ethylmaleimide or Cysteine

The role of sulfhydryl/disulfide interchange in determining the water vapor permeability (WVP) and mechanical properties of edible films from whey protein isolate (WPI) was investigated. Nearly total inhibition of sulfhydryl/disulfide interchange by the sulfhydryl blocking agent N-ethylmaleimide (NEM) reduced protein solubility by 50%, but had no effect on WVP, Young's modulus, yield stress, or breaking stress. Breaking strain was reduced significantly at high levels of added NEM. Reduction of disulfide bonds with cysteine had no effect on WVP. The effects of hydrogen bonding far outweigh those of disulfide bonding in WPI films. Keywords: Edible films; biodegradable films; elastic modulus; tensile stress; sulfhydryl/disulfide interchange; thiol/disulfide interchange