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Emulsion Stability (emulsion + stability)

Distribution by Scientific Domains

Chemistry	95%

Selected Abstracts

Characterization of Phase Separation Behavior, Emulsion Stability, Rheology, and Microstructure of Egg White,Polysaccharide Mixtures

JOURNAL OF FOOD SCIENCE, Issue 6 2009
E. Alben Erçelebi
ABSTRACT:, Phase separation behavior of egg white-pectin/guar gum mixtures was investigated. These systems led to phase separation arisen by either depletion flocculation or thermodynamic incompatibility. The influence of polysaccharides on the emulsifying activity index (EAI), emulsifying stability index (ESI), creaming stability, microstructure, and rheological properties was also studied at different polysaccharide concentrations (0% to 0.5%, [w/v]). Increasing pectin and guar gum concentration from 0.01% to 0.5% significantly improved EAI by 51% and 25%, respectively. The highest ESI and EAI values were obtained in the presence of 0.5% (w/v) pectin/guar gum. Microscopic images showed that emulsions containing polysaccharides had small droplets as compared to that of emulsions without polysaccharides. The addition of polysaccharides improved emulsion stability against creaming. Egg white-stabilized emulsions with and without polysaccharides reflect the pseudoplastic behavior with,n,< 1.0. Polysaccharides, especially at high concentrations, affected the viscoelastic behavior of the emulsions; storage (G,) and loss modulus (G,) crossed-over at lower frequency values as compared to that of emulsions containing no polysaccharide. [source]

Functional, Nutritional, and Rheological Properties of Protein Powders from Arrowtooth Flounder and their Application in Mayonnaise

JOURNAL OF FOOD SCIENCE, Issue 2 2005
Subramaniam Sathivel
ABSTRACT: Arrowtooth flounder soluble protein powder (AFSP) and arrowtooth flounder insoluble protein powder (AFISP) were evaluated for their functional, nutritional, and rheological properties. AFSP and AFISP contained 80% and 79% protein and 5.9% and 14.9% fat, respectively. Yield of AFSP (8.6%) was less than AFISP (13.1%). AFSP and AFISP had desirable essential amino acid and mineral contents. Emulsion stability of AFSP was greater than AFISP. Fat and water absorptions (mL/g protein) were 5.2 and 1.8 for AFSP, respectively, and 3.3 and 4.2 for AFISP Mayonnaises made from AFSP had greater emulsion stability than mayonnaise made from AFISP. Mayonnaises from both AFSP and AFISP possessed pseudoplastic and viscoelastic characteristics. [source]

Emulsifying properties of gum kondagogu (Cochlospermum gossypium), a natural biopolymer

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2009
Ganga Modi Naidu Vegi
Abstract BACKGROUND: Natural polymers are widely used as emulsifying agents in the food and pharmaceutical industries because of their low cost, biocompatibility and non-toxic nature. In the present study, emulsifying properties of the novel natural biopolymer gum kondagogu (GKG) were investigated. GKG solutions of different concentrations (0.1,0.6% w/v) were prepared in water and emulsified with liquid paraffin oil (40% v/v) in a high-speed homogeniser. Flow properties of the emulsions were measured using a rheometer. Emulsion stability and droplet size distribution were determined by visual observation, photomicrography and laser-scattering particle size distribution analysis. RESULTS: The emulsions prepared with GKG showed pseudoplastic behaviour. The size of oil droplets and the viscosity of emulsions at concentrations of 0.4,0.6% w/v showed little change over time (up to 30 days), indicating that the emulsions were stable. Measurements of the zeta potential of emulsions adjusted to different pH, with and without added electrolyte, showed that the stabilisation of emulsions with GKG was due to mutual repulsion between electrical double layers of particles and adsorption of macromolecules on oil droplets. CONCLUSION: The results of this experimental investigation show that GKG is a good emulsifying agent even at low concentrations, with many potential applications in the food and pharmaceutical industries. Copyright © 2009 Society of Chemical Industry [source]

Physicochemical Properties and Functionality of Rice Bran Protein Hydrolyzate Prepared from Heat-stabilized Defatted Rice Bran with the Aid of Enzymes

JOURNAL OF FOOD SCIENCE, Issue 1 2003
S. Tang
ABSTRACT: Molecular size, thermal properties, hydrophobicity, nitrogen solubility, and emulsifying and foaming properties were determined for protein products from heat-stabilized defatted rice bran. The freeze-dried and spray-dried proteins had molecular sizes between 6.5 to 66.2 kDa; denaturation temperatures of 84.1 and 84.6 °C, enthalpies of 2.5 and 2.37 J/g, hydrophobicities of 20677 and 22611, maximum solubilities of 66.3% and 66.1% at pH 12.0, emulsifying capacities of 0.19 and 0.18, emulsion stabilities of 16.5 and 17.3 min, foam capacities of 4.0 mL and 4.2 mL, and negligible foam stabilities. These results demonstrated that the extracted rice bran protein has potential as a nutraceutical ingredient in food applications. [source]

Emulsifying activity and emulsion stability of corn gluten meal ,

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2001
Y Victor Wu
Abstract Corn gluten meal with good emulsifying activity and emulsion stability may have potential in food uses. Commercial corn gluten meal from various producers had a pH around 4 and showed no emulsifying activity. Reducing the particle size to below 15,µm or increasing the pH to 6.6 (with particle size above 53,µm) did not improve the emulsifying activity. When the particle size was reduced to below 44,µm and the pH was adjusted to 6.6 or above, good emulsifying activity and good emulsion stability could be obtained. The emulsifying activities of corn gluten meals (<44,µm) from four different producers at around pH 8 ranged from 49.3 to 51.5 and the corresponding emulsion stabilities ranged from 39.7 to 49.5. There was no significant variation in emulsifying activity between pH 6.9 and 7.8 when NaOH, LiOH and KOH were used to adjust the pH, but LiOH- and KOH-adjusted meal at around pH 7.8 showed better emulsion stability than NaOH-adjusted meal. Good emulsifying activity of corn gluten meal could be obtained in NaCl solutions at sufficiently high pH. Published in 2001 for SCI by John Wiley & Sons, Ltd. [source]

Synthesis and characterization of imidazolinium surfactants derived from tallow fatty acids and diethylenetriamine

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 10 2008
Divya Bajpai
Abstract This paper describes the synthesis of long-chain dialkylamido imidazolines based on tallow fatty acids and diethylenetriamine, followed by their quaternization. Imidazolines were obtained by non-solvent microwave synthesis using calcium oxide as support, which were then quaternized by using dimethyl sulfate as a quaternizing agent and iso -propanol as a solvent, to produce cationic imidazolinium salts. The synthesized cationic imidazoline surfactants were evaluated for yield and cationic content. The instrumental techniques, viz. FT-IR and 1H-NMR, verified the formation of imidazolines and their subsequent quaternization. The surface-active and performance properties of the cationic imidazolines in terms of critical micelle concentration, surface tension, dispersibility, emulsion stability, softening, rewettability and antistatic properties were also reported. [source]

Physicochemical, textural, sensory characteristics and storage stability of goat meat patties extended with full-fat soy paste and soy granules

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2008
Arun K. Das
Summary The performance of full-fat soy paste (FFSP) with reduced beany flavour made by simple processing technology was compared with the commercially available textured soy granules in goat meat patties. Addition of soy proteins (soy paste and soy granules) did not significantly affect the emulsion stability and product yield. Shrinkage of patties with soy paste was comparable with control. A significant (P < 0.05) reduction in redness and increase in yellowness of patties was due to addition of soy proteins than in control. Patties with soy paste had comparable but slightly higher total lipid and cholesterol content with that of control but significantly (P < 0.05) higher than patties with soy granules. Lower force was required to compress or shear the sample, as hardness decreased in soy-added patties. Flavour and overall acceptability scores between control and patties with soy paste did not differ significantly, whereas patties with soy granules were rated significantly lower. The patties remained stable with minor changes in physicochemical, microbiological and sensory quality during refrigerated storage (4 ± 1 °C) for 20 days. It is concluded from this study that FFSP had potential application similar to commercially available textured soy granules in comminuted meat products. [source]

Effect of egg proteins on the quality and refrigerated storage life of chicken patties made with broiler-spent hen meat and by-products,

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007
A. Kalaikannan
Summary The effects of whole egg powder (WEP), dried albumen (DA), dried yolk (DY) at a 1% level and liquid egg (LE) at a 3.7% level on the quality characteristics and refrigerated storage (4 ± 1 °C) stability of chicken patties made with meat and by-products of broiler-spent hens were evaluated. The addition of egg powders significantly enhanced the emulsion stability (ES) and product yield compared with control and LE. There was a marked increase in moisture content and sensory attributes by the addition of egg powders. During the refrigerated storage (4 ± 1 °C), thio-barbituric acid number (TBARS), aerobic plate count (APC) and psychrophilic count increased in all samples. Incorporation of DA and DY significantly reduced the TBARS number and APC during the storage over control. The addition of DA, DY and WEP significantly lowered the psychrophilic counts. Treated and control patties packaged in LDPE (low-density polyethylene) pouches were acceptable for 20 days and 15 days, respectively. [source]

The emulsifying properties of a polysaccharide isolated from the fruit of Cordia abyssinica

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2004
Mudadi Albert Nhamoiesu Benhura
Summary Polysaccharide was isolated from Cordia abyssinica and its effect, at differing concentrations, on its emulsifying ability was determined. Emulsions of vegetable oil containing up to 1% of the polysaccharide in phosphate pH 7.4 buffer, were prepared by using a hand piston homogenizer. Emulsification was assessed by diluting samples of the emulsions in sodium dodecyl sulphate and measuring absorbance at 500 nm. Addition of increasing concentrations of the polysaccharide up to 1% enhanced emulsification and emulsion stability. Above 1% concentration the polysaccharide solutions were too viscous for making emulsions conveniently. At a constant concentration of the polysaccharide, addition of up to a 1% concentration of salt enhanced emulsion formation. Further addition of salt above 1% resulted in no further changes in emulsifying ability, but the stability of the emulsions formed decreased on increasing the concentration of salt above 1%. The effect of pH on emulsifying ability was investigated by preparing emulsions using buffers of different pH, from pH 3 to pH 13. The polysaccharide had poor emulsifying ability below pH 7. Emulsifying ability increased with pH between pH 7 and 11. At pH above 11 there was a decrease in emulsifying ability. [source]

MANUFACTURING FUNCTIONALITY OF CHILLED VENISON AND BEEF

JOURNAL OF FOOD QUALITY, Issue 5 2007
M.M. FAROUK
ABSTRACT The functional properties of venison and beef semimembranosus muscle stored at ,1.5C for 4 weeks were compared. Sarcoplasmic protein solubility (SPS), malondialdehyde (MDA) and reactive sulfhydryl (SH) contents were higher in venison compared with beef (P < 0.001). Cooked batter torsion stress, tensile strength, rigidity and yield were higher in beef compared with venison (P < 0.01). Venison and beef did not differ in total protein solubility (TPS), emulsion activity index (EAI) and emulsion stability (ES) (P > 0.05). TPS, EAI, ES, MDA, torsion stress and strain, tensile strength and extensibility in meats from both species increased, and SPS and SH decreased with chilled storage time (P < 0.01). Within the parameters of this study, chilled beef had a better manufacturing functionality compared with venison. Manufacturing functionality in meats from both species improved with chill storage time, but the improvement was more marked in beef compared with venison. PRACTICAL APPLICATIONS The following are some of the practical applications of this research: (1) processing parameters used to optimize the manufacturing functionality of beef are not suitable for venison because the latter tenderize much faster than beef with negative implications to manufacturing functionality; (2) the current practice of not vacuum packaging frozen manufacturing meat will have a more deleterious effect on the functionality of venison compared with beef because of the higher rate of lipid oxidation in venison; and (3) the best time to use chilled venison and beef for maximum functionality is at 2 or 3 weeks of storage at ,1.5C. [source]

Rheological and Functional Properties of Catfish Skin Protein Hydrolysates

JOURNAL OF FOOD SCIENCE, Issue 1 2010
Huaixia Yin
ABSTRACT:, Catfish skin is an abundant and underutilized resource that can be used as a unique protein source to make fish skin protein hydrolysates. The objectives of this study were to isolate soluble and insoluble proteins from hydrolyzed catfish skin, study the rheological and functional properties of the protein hydrolysates, and evaluate the properties of emulsions made from the protein powders. Freeze-dried catfish skin soluble (CSSH) and insoluble hydrolysate (CSISH) powders were analyzed for proximate analysis, emulsion stability, fat absorption, amino acids, color, and rheological properties. CSSH had significantly (P,< 0.05) higher protein, ash, and moisture content but lower fat content than that of CSISH. The yield of CSSH (21.5%± 2.2%) was higher than that of CSISH (3%± 0.3%). CSISH had higher emulsion stability than CSSH. CSSH was light yellow in color and CSISH was darker. The mean flow index values for emulsion containing CSSH (ECSSH) and CSISH (ECSISH) were both less than 1, indicating that they were both pseudoplastic fluid. The G, and G, values for the ECSISH were higher than that of ECSSH, indicating that the viscoelastic characteristic of the emulsion containing CSISH was greater than that of the emulsion containing CSSH. The study demonstrated the CSSH and CSISH had good functional and rheological properties. They have potential uses as functional food ingredients. [source]

Characterization of Phase Separation Behavior, Emulsion Stability, Rheology, and Microstructure of Egg White,Polysaccharide Mixtures

Effect of Actinidin on the Protein Solubility, Water Holding Capacity, Texture, Electrophoretic Pattern of Beef, and on the Quality Attributes of a Sausage Product

JOURNAL OF FOOD SCIENCE, Issue 3 2009
M. Aminlari
ABSTRACT:, The objective of this study was to study the effect of actinidin, a sulfhydryl protease from kiwi fruit, on the protein solubility (nitrogen solubility index [NSI]), water holding capacity (WHC), texture, and SDS,PAGE pattern of beef and to evaluate the effect of pretreatment of beef with actinidin on the quality attributes of a sausage product. Actinidin was partially purified by precipitation with ammonium sulfate, followed by DEAE-Sephadex column chromatography. Actinidin significantly (P < 0.05) increased NSI and WHC of beef; the highest NSI and WHC (approximately 20% and 8% increase, respectively) was observed when beef was incubated with 0.9 unit enzyme/g beef. Texture analysis indicated increased tenderization (10% decrease in shear force) when slices of cattle beef were treated with actinidin at 37 °C for 2 h. SDS,PAGE results indicated appearance of several low molecular weight bands (<10 kDa) after treating beef with different levels of actinidin for 30 or 60 min. Slight changes in protein band in the range of 100 to 120 kDa and 13 to 25 kDa were also observed. Use of actinidin-tenderized beef significantly improved emulsion stability, texture, and organoleptic properties of the sausage product. [source]

Comparative Structural, Emulsifying, and Biological Properties of 2 Major Canola Proteins, Cruciferin and Napin

JOURNAL OF FOOD SCIENCE, Issue 3 2008
J. Wu
ABSTRACT:, Canola is an economically important farm-gate crop in Canada. To further explore the potential of canola protein as value-added food and nutraceutical ingredients, a better understanding of fundamental properties of 2 major canola proteins is necessary. Two major protein components, cruciferin and napin, were isolated from defatted canola meal by Sephacryl S-300 gel filtration chromatography. SDS-PAGE showed that cruciferin consists of more than 10 polypeptides, and noncovalent links are more important than disulphide bonds in stabilizing the structural conformation. Napin consists of 2 polypeptides and is stabilized primarily by disulphide bonds. Purified cruciferin showed 1 major endothermic peak at 91 °C compared with that of 110 °C for napin. Emulsion prepared by cruciferin showed significant higher specific surface area and lower particle size than that of napin. The study indicated that the presence of napin could detrimentally affect the emulsion stability of canola protein isolates. Hydrolysates from cruciferin and napin showed potent angiotensin I-converting enzyme inhibitory activity (IC50: 0.035 and 0.029 mg/mL, respectively), but weaker than that of canola protein isolate hydrolysate (IC50: 0.015 mg/mL). [source]

Functional, Nutritional, and Rheological Properties of Protein Powders from Arrowtooth Flounder and their Application in Mayonnaise

Effect of Chemically Modified Soy Proteins and Ficin-tenderized Meat on the Quality Attributes of Sausage

JOURNAL OF FOOD SCIENCE, Issue 1 2003
R. Ramezani
ABSTRACT: The purpose of this investigation was to use ficin-tenderized meat and cysteine-modified soy proteins in the production of bologna and to evaluate the effect of these modifications on water-holding capacity (WHC), emulsion stability (ES), texture, and protein solubility. The effect of ficin on meat protein was also evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Results indicated that both ficin-tenderized meat and modified soy proteins substantially improved WHC, ES, and other quality factors. SDS-PAGE results showed the disappearance of several protein bands in ficin-treated meat. Solubility of meat proteins increased when ficin was used for meat tenderization. The results of this study indicated that some quality attributes of meat products can be improved by enzymatic and chemical modification of protein sources in the manufacture of meat products. [source]

Effects of sand and process water pH on toluene diluted heavy oil in water emulsions in turbulent flow

AICHE JOURNAL, Issue 1 2009
Chandra W. Angle
Abstract The presence of sand in heavy oil production is known to enhance oil recovery. Sand can also be detrimental depending on the properties of the sand,water interface. In this process, the water soluble material interacts with both sand and oil droplets and affects emulsion stability. The formation and stability of heavy oil-in-water emulsions during turbulent flow using batch process stirred-tank mixing of oil, sand, and water were investigated at three pH. Size distributions were measured by laser diffraction. High-speed video photomicrography was used to observe the process during mixing. Results showed that the presence of sand enhanced formation of stable, fine emulsion at basic pH 8.5. When the pH of the water was reduced below 6.5 both sand and droplets surface properties changed, the emulsions became less stable and coalescence was apparent. The sand grains acted as coalescers at low pH and enhanced breakage at high pH. © Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2008 AIChE J, 2009 [source]

Model salad dressing emulsion stability as affected by the type of the lupin seed protein isolate

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2006
Evdoxia Papalamprou
Abstract Model salad dressing emulsions of an oil volume fraction of 0.50 were prepared using two types of lupin seed protein isolate (LSPI) differing in the method applied for their isolation and their protein composition. The dressing stability against creaming and droplet coalescence were studied and correlated with data on oil droplet size, rheological characteristics and the amount of protein adsorption at the droplet surfaces. Model salad dressing emulsions containing the isolate, mainly composed of lupin globulins, exhibited higher stability and more pronounced rheological characteristics compared to those prepared with the isolate enriched in albumins or with the mixture of the two isolates. The lupin albumins appeared to displace the globulins from the droplet surfaces, following competitive adsorption from mixtures of the two types of the lupin isolates. The results are discussed in terms of droplet interaction and rearrangement as they are influenced by the presence of the adsorbed protein molecules and aggregates which appear to determine long-term stability of the emulsion systems. Copyright © 2006 Society of Chemical Industry [source]

Effect of medium molecular weight xanthan gum in rheology and stability of oil-in-water emulsion stabilized with legume proteins

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2005
Evdoxia M Papalamprou
Abstract Xanthan gum is a water-soluble extracellular polysaccharide that has gained widespread commercial use because of its strong pseudoplasticity and tolerance to high ionic strength, which bring unique rheological properties to solutions. This study compares and evaluates the emulsifying properties of oil-in-water (30:70 v/v) emulsions stabilized with lupin and soya protein isolates and medium molecular weight xanthan gum. The protein was obtained by an isoelectric precipitation method and the polysaccharide was produced by Xanthomonas campestris ATCC 1395 in batch culture in a laboratory fermenter (LBG medium) without pH control. The addition of xanthan gum in the emulsion formulation enhances emulsion stability through the phenomenon of thermodynamic incompatibility with the legume protein, resulting in an increase of the adsorbed protein at the interface. The emulsion stability is also enhanced by a network structure built by the polysaccharide in the bulk phase. Copyright © 2005 Society of Chemical Industry [source]

Emulsifying properties of gelatin conjugated to pectin under alkaline conditions

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2005
Nickolaos G Diftis
Abstract Gelatin,pectin mixed solution incubated under mild alkaline conditions for a period of 4 h exhibited an improvement of emulsion stability in terms of both droplet coalescence and serum separation. Application of SDS,PAGE provided evidence for gelatin,pectin hybrid formation possibly due to amide bonds between the lysine group residues of protein and the esterified carboxyl groups of the polysaccharide. The superior stabilizing properties of the heat-treated protein,polysaccharide conjugate is attributed to the enhancement of the repulsive steric forces operating between emulsion oil droplets, as a result of conjugate adsorption through their protein moiety. Copyright © 2004 Society of Chemical Industry [source]