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Protein Films (protein + film)

Distribution by Scientific Domains

Chemistry	77%
Polymers and Materials Science	22%

Kinds of Protein Films

whey protein film

Selected Abstracts

Antimicrobial Effects of Lactoferrin, Lysozyme, and the Lactoperoxidase System and Edible Whey Protein Films Incorporating the Lactoperoxidase System Against Salmonella enterica and Escherichia coli O157:H7

JOURNAL OF FOOD SCIENCE, Issue 7 2005
Seacheol Min
ABSTRACT: Lactoferrin (LF), lysozyme (LZ), the lactoperoxidase system (LPOS), and edible whey protein isolate (WPI) films incorporating LPOS were studied for inhibition of Salmonella enterica and Escherichia coli O157:H7. Antimicrobial effects of LF (5 to 40 mg/mL), LZ (1 to 20 mg/mL), and LPOS (0.5% to 5.0% [w/v] [0.03,.25 g/g, dry basis]) were examined by measuring turbidity of antimicrobial-containing media after inoculation and by examining cell inhibition by WPI films incorporating LPOS (LPOS-WPI films) on an agar recovery medium. Elastic modulus (EM), tensile strength (TS), percent elongation (%E), oxygen permeability (OP), and Hunter L, a and b of WPI films incorporating 0.03 to 0.25 g/g of LPOS were compared with those of plain WPI films without LPOS. The growth of S. enterica and E. coli O157:H7 (4 log colony-forming units [CFU]/mL) in tryptic soy broth (TSB) was not prevented by LF at ,20 and ,40 mg/mL, respectively. S. enterica and E. coli O157:H7 in TSB were not inhibited by LZ at , 6 and , 20 mg/mL, respectively. LPOS at concentrations of 2.75% (w/v) and 1.0% (w/v) reduced S. enterica and E. coli O157:H7 to below the limit of detection (1 CFU/mL) in TSB, respectively. LPOS-WPI films (0.15 g/g) completely inhibited S. enterica and E. coli O157:H7 (4 log CFU/cm2), inoculated either onto agar before placing the film disc or onto top of the film disc. Incorporation of 0.25 g/g of LPOS decreased EM, TS, and %E. The oxygen barrier property of WPI films was improved with the incorporation of LPOS at 0.15 to 0.25 g/g. [source]

Plasticizing Effects of Beeswax and Carnauba Wax on Tensile and Water Vapor Permeability Properties of Whey Protein Films

JOURNAL OF FOOD SCIENCE, Issue 3 2005
Pau Talens
ABSTRACT: The possible plasticizing effect of beeswax (viscoelastic wax) and carnauba wax (elastic wax) on tensile and water vapor permeability properties of whey protein isolate (WPI) films was studied. For the experiments, 3 groups of films with different WPI:glycerol ratios (1:1; 1.5:1; 2:1, 2.5:1, and 3:1) were prepared. The 1st group was made without the addition of wax, and the latter 2 groups were made with the addition of beeswax and carnauba wax, respectively, mixing 1 part of wax to 1 part of WPI. Lipid particle size, water vapor permeability, tensile properties, and thickness of films were analyzed and measured. The results show that the incorporation of beeswax produced a plasticizing effect in WPI:glycerol films, whereas carnauba wax produced an anti-plasticizing effect. The moisture barrier properties of WPI:glycerol films benefit from the addition of beeswax, by both increase of the hydrophobic character and decrease of the amount of hydrophilic plasticizer required in the film. [source]

Nisin Diffusion in Protein Films: Effects of Film Type and Temperature

JOURNAL OF FOOD SCIENCE, Issue 8 2002
A. Teerakarn
ABSTRACT: Protein films [cast corn zein (CCZ), heat-pressed corn zein (HPCZ), cast wheat gluten (CWG), and heat-pressed wheat gluten (HPWG)] were studied at different exposure temperatures (5, 25, 35, and 45 °C) to determine nisin diffusion in aqueous model systems. Kinetics of nisin diffusion in protein films followed a Fickian diffusion model. The CCZ had the lowest nisin diffusivity and highest nisin retention. Diffusivities in HPCZ, CWG, and HPWG films were not significantly different. Temperature dependence of nisin diffusion in all films followed an Arrhenius model, which indicated no morphological changes within 5 to 45 °C. The activation energy for nisin diffusion in corn-zein films was higher than that in wheat-gluten films. [source]

Properties and Bioapplications of Blended Cellulose and Corn Protein Films

MACROMOLECULAR BIOSCIENCE, Issue 9 2009
Quanling Yang
Abstract A series of blend films have been prepared from cellulose and corn protein in a NaOH/urea solution by a simple, low cost, and ,green' pathway. Their structure and properties are characterized by amino acid analysis, X-ray diffraction, scanning electron microscopy, thermogravimetry, and tensile testing. The results reveal that a certain miscibility exists between cellulose and corn protein and their thermal stability and mechanical properties are improved significantly, compared with the protein materials, when the protein content is less than 18 wt.-%. The protein, which contains tyrosine and histidine, could remain in the blend films after being washed for ten days, which indicates the strong hydrogen bonding between the hydroxy groups of cellulose and the hydroxyphenyl of tyrosine and imidazolyl of histidine in the protein. Furthermore, they exhibit good biocompatibility capable of supporting cell adhesion and proliferation. [source]

Nisin Diffusion in Protein Films: Effects of Film Type and Temperature

Studies on glass transition temperature of mono and bilayer protein films plasticized by glycerol and olive oil

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Babak Ghanbarzadeh
Abstract Thermomechanical and thermal properties of whey protein, maize prolamin protein (zein), and the laminated whey protein,zein films were studied. The dynamic mechanical (thermal) analysis (DMTA) results showed that the single zein film had higher Tg than single whey protein and zein,whey laminated films. The shift in the Tg values of films from 31.2°C in whey protein film and 88.5°C in the zein film to 82.8°C in the laminated whey protein,zein films may be implied some interaction formation between the two polymers. The small tan , peaks were observed at ,50°C in zein,glycerol films and at ,22.37°C in the whey protein films and can be related to ,-relaxation phenomena or presence of glycerol rich region in polymer matrix. Zein-olive oil and zein,whey protein,olive oil films showed tan , peaks corresponded the Tg values at 113.8, and 92.4°C, respectively. Thus, replacing of glycerol with olive oil in film composition increased Tg. A good correspondence was obtained when DSC results were compared with the tan , peaks in DMTA measurements. DSC thermograms suggested that plasticizers and biopolymers remained a homogeneous material throughout the cooling and heating cycle. The results showed that Tg of zein,glycerol films predicted by Couchman and Karasz equation is very close to value obtained by DSC experiments. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Factors Determining Yield Stress and Overrun of Whey Protein Foams

JOURNAL OF FOOD SCIENCE, Issue 5 2002
P.J. Luck
ABSTRACT: Foams were formed by whipping whey protein solutions (15% w/v protein) containing NaCl, CaCl2, lactose, or glycine. Foam overrun and yield stress were determined. Foams made from whey protein ingredients have greater overrun and yield stress if the concentration of ,-lactoglobulin is high relative to a-lactalbumin. The presence of 0.4 M CaCl2 in the foaming solution increases overrun and yield stress for ,-lactoglobulin and a-lactalbumin. The high yield stress of ,-lactoglobulin and a-lactalbumin foams made from solutions containing CaCl2 suggests that CaCl2 is altering rheological properties of the interfacial protein film and/or contributing to protein aggregation or network formation in the lamellae. [source]

Adsorption and rheological properties of biopolymers at the air-water interface

AICHE JOURNAL, Issue 7 2006
Rosa Baeza
Abstract Dynamics of adsorption and viscoelasticity of biopolymers (,-lactoglobulin (,-lg) + polysaccharides (PS)) at 20 °C and pH 7 have been studied. Protein concentration in the bulk phase was 0.1 wt %, and the concentration of polysaccharides (xanthan gum, ,-carrageenan, and propylenglicol alginate with different degrees of esterification and viscosity) was varied from 0.1% to 0.5 wt %. The results reveal a significant effect of surface-active and non surface-active polysaccharides on the dynamics of the formation and viscoelasticity of adsorbed films at the air-water interface. The rate of diffusion of the biopolymers increased in the mixed systems, but the effect was more significant at the highest concentration of polysaccharide (0.5 wt %). The rate of rearrangement of the adsorbed films decreased in the presence of polysaccharides as compared to the protein film. Competitive adsorption, complexation and limited thermodynamic incompatibility between ,-lactoglobulin and polysaccharide would explain the observed effects. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source]

Micropipette manipulation: A technique to evaluate the stability of water-in-oil emulsions containing proteins

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2004
Lene Jorgensen
Abstract The interfacial properties and stability of water-in-oil emulsions containing protein were studied using micromanipulation. Micropipettes were used to produce individual water droplets in oil in a controlled manner on the micron scale. The pipettes were then used to bring two droplets into contact in order to observe fusion. The occurrence of fusion was investigated as a function of the compositions of both the continuous (oil) and dispersed (aqueous) phases. Various proteins, i.e., insulin, growth hormone, or serum albumin, were dissolved in the dispersed phase. When low concentrations of surfactants or no surfactant were present in the oil phase, a condensed protein film was formed at the surface of the droplets, which was revealed by the irregular topology of the droplet surface viewed with contrast microscopy. At higher surfactant concentrations, this topology was not observed nor was the stability apparently affected; emulsion droplets coalesce immediately upon contact with each other. There seems to be a limiting surfactant concentration, which stabilizes the droplets toward fusion and prevents formation of a condensed surface film, when the droplets contain protein. The technique exhibits potential for examination of the effects of various excipients on the coalescence stability of emulsion droplets. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:2994,3003, 2004 [source]

Rice bran protein-based edible films

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2008
Abayomi P. Adebiyi
Summary The development of degradable and edible films from protein sources has drawn significant attention for the utilisation of natural resources as well as for the alleviation of the environmental burden. Rice bran protein (RBP) was applied to protein film preparation in this study. The protein solutions were casted on plastic tissue culture dishes with glycerol as a plasticiser after heat treatment. Functional properties of the films were then measured. The puncture strength (PS) of RBP films increased up to pH 8.0 and then decreased. PS of protein films depends on the degree of protein purity, quality and composition. Higher concentration of glycerol weakened the films. The pH affected the water solubility of RBP films and the films showed least solubility at pH 3.0. RBP could be utilised in the preparation of degradable protein-based films. The RBP-based film had functional properties comparable to those of the soy protein-based ones. [source]

An analysis of water vapour diffusion in whey protein films

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2003
Cristiana M. P. Yoshida
Summary The macroscopic aspects of moisture transmission in whey protein films were determined by measuring water vapour adsorption. A theoretical model was constructed in which two kinds of water vapour fluxes were considered: one originating from diffusion, whilst the other was a flux due to the gravitation drift of moisture. The comparison of theoretical and experimental results showed that only the diffusion process was present. [source]

Moisture adsorption by milk whey protein films

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2002
C. M. P. Yoshida
Edible films, using whey protein as the structural matrix, were tested for water vapour diffusion properties. Whey protein films were prepared by dispersing 6.5% whey protein concentrate (WPC) in distilled water with pH kept at 7.0. Glycerol was the plasticizer agent. Film slabs (13.5 × 3.5 cm) were put in a chamber at 25 °C and 75% relative humidity, being held in vertical planes for different periods of time. The mass gain was determined throughout the experiment. We show that moisture adsorption by milk whey protein films is well described by a linear diffusion equation model. After an adsorption experiment was performed the solution of the diffusion equation was fitted to the data to determine the diffusion coefficient of the material. [source]

Studies on glass transition temperature of mono and bilayer protein films plasticized by glycerol and olive oil

EFFECT OF OLIVE OIL AND GLYCEROL ON PHYSICAL PROPERTIES OF WHEY PROTEIN CONCENTRATE FILMS

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2008
MAJID JAVANMARD
ABSTRACT Olive oil was incorporated into whey protein through emulsification to produce films. Whey protein films were prepared by dispersing 10% protein in distilled water; and plasticized with different levels of glycerol (glycerol : protein [Gly : pro ] = 0.5 and 0.6). Olive oil was added at different levels (oil : pro = 0.0, 0.2, 0.3 and 0.4). The emulsion films were evaluated for mechanical properties, water vapor permeability (WVP) and opacity. Increasing the levels of Gly or olive oil in the films led to decreases in modulus and tensile strength. Increasing Gly content of films at oil/pro ratios of 0.2, 0.4 led to slight increases in elongation (EL). Increasing the oil : pro ratio further resulted in a decrease in EL for all films. No significant difference in WVP and opacity was observed between films made from mixtures of various proportions of whey protein concentrate,Gly with increasing olive oil (addition) at all levels of the plasticizer. PRACTICAL APPLICATIONS The main advantages of using edible films are extending food shelf life, improving food quality, adding value to the edible film-forming polymer and reducing synthetic packaging materials. Whey, obtained as a by-product in cheese, is produced in large quantities and has excellent functional properties and could potentially be used for edible films. [source]