Sodium Caseinate Concentration Research Articles

Impact of cationic surfactant on the self-assembly of sodium caseinate.

The impact of a cationic surfactant, dodecylammonium chloride (DDACl), on the self-assembly of sodium caseinate (SC) has been investigated by light scattering, zeta potential, and rheological measurements as well as by microscopy (transmission electron and confocal laser scanning microscopy). In SC dilute solutions concentration-dependent self-assembly proceeds through the formation of spherical associates and their aggregation into elongated structures composed of connected spheres. DDACl interacts with SC via its hydrophilic and hydrophobic groups, inducing changes in SC self-assembled structures. These changes strongly depend on the surfactant aggregation states (monomeric or micellar) as well as concentration ratio of both components, leading to the formation of soluble and insoluble complexes of nano- to microdimensions. DDACl monomers interact with SC self-assembled entities in a different way compared to their micelles. Surfactant monomers form soluble complexes (similar to surfactant mixed micelles) at lower SC concentration but insoluble gelatinous complexes at higher SC concentration. At surfactant micellar concentration soluble complexes with casein chains wrapped around surfactant micelles are formed. This study suggests that the use of proper cationic surfactant concentration will allow modification and control of structural changes of SC self-assembled entities.

Physical Properties and Oxidative Status of Concentrated-from-Fish Oils Microencapsulated in Trehalose/Sodium Caseinate Matrix

Foods supplemented with omega-3 fatty acids have attracted much attention in the past decade. However, it is difficult to protect polyunsaturated fatty acids from oxidation. Microencapsulation is a technological process used with the aim to protect oils against oxidation or chemical deterioration, to mask unpleasant flavors or retain aromas, and/or to powder polyunsaturated fatty acids for food fortification purposes. The objective of this study was to analyze physical properties and oxidation status of microencapsulated concentrated-from-fish oils. Powders were prepared from emulsions formulated with 10 wt.% of concentrated-from-fish oils as fat phase and 20 or 30 wt.% trehalose solution that also contained 0.5, 2.0, or 5.0 wt.% sodium caseinate as aqueous phase. Encapsulation efficiency was higher for powders coming from 20 wt.% trehalose emulsions, and the percentage of retention of core material increased with increasing sodium caseinate concentration. The powder prepared from 20 wt.% trehalose and 5 wt.% sodium caseinate showed the highest retention of core material. This powder had lower water content and an amorphous matrix. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, used for this new application, allowed proving that trehalose/sodium caseinate matrix was efficient for microencapsulation of polyunsaturated oils and that concentrated-from-fish oils was protected from oxidation in powder form. Spectra were very similar to the original oil without any treatments. Most likely, the oxidation products found when core material was extracted were formed during extraction steps.

Influence of formulation ingredients of dry fat semi-finished products for whipping on mechanical strength of foam masses

The mechanical strength of foam-emulsion systems based on formulation ingredients of dry fat semi-finished products for whipping was studied. Experimental studies of the influence on the mechanical strength of the foam-emulsion systems of a stabilizer, surface-active substances (GMS, lecithin’s) and sunflower oil are presented. The patterns concerning the influence of concentration of kappa-carrageenan, surface-active substances, sunflower oils on the mechanical strength of foam-emulsion systems were defined in the paper for the first time. It was found that using GMS at the concentration rate of 1...6% increases the value of the boundary stress of foam offsets in foam-emulsion systems “sodium caseinate-GMS-oil” with the sodium caseinate content varying between 1.0 and 2.0% and the oil content fluctuating from 2.5 to 10.0%. Using the lecithin’s in foam-emulsion systems of “sodium caseinate-GMS-lecithin’s-oil” at the concentration ranging within 0.1...0.2% increases the mechanical strength, while at higher concentrations reduces it. It was found that for increasing the mechanical strength of foam-emulsion systems, it is appropriate to use kappa-carrageenan, which enhances the foam strength that is caused by the increase in viscosity and the formation of a gel-like structure. The rational concentration of kappa-carrageenan in the system (0.5...1.0%) was estimated, which increases the offset boundary stress by 1.5...1.6 times, i.e. amounting to 1120...1270 Pa, and the foaming capacity from 640 ± 1 % to 780...800%. The obtained results allowed developing a fundamentally new technology of dry fat semi-finished products for whipping by means of spraying a fat blend on a powder-like filler with high technological properties, which are gained at the determined concentrations of sodium caseinate, kappa-carrageenan, GMS, lecithin’s.

Structure and properties of hydroxypropyl methyl cellulose—Sodium caseinate film cross-linked by TGase

• The number of entanglement within the films increased by increasing the protein concentration. • High concentration of HPMC were a limiting factor for protein–protein interaction. • Increasing HPMC concentration, increased the stiffness of the films and decreased the elongation at break. • The different ratio of HPMC/CS film did not affect the permeability to water vapour of the films. The objective of the present work was to study the influence of composition of hydroxypropyl methyl cellulose (HPMC)–sodium caseinate (SC) edible films cross-linked by transglutaminase enzyme (mTGase), on film structure and functional properties. To this end, SDS–PAGE, scanning electronic microscopy and mechanical analysis at low and at high deformation were performed. The thickness, solubility and water vapor permeability of films were also studied. Our results show that the enzyme mTGase allows the formation of a stiffer film, which behaves more like a solid material than does a film not cross linked with TGase. HPMC may well act as fillers of the protein network, affecting the mechanical spectra of the film as a function of the HPMC/SC ratio. In the presence of high HPMC concentrations the mechanical spectra of the blends may be similar to HPMC film. Only in the presence of high SC concentration does the order of relaxation ( α ) considerably increase from 0.0464 ± 0.002 to 0.111 ± 0.002 showing an increase in intermolecular cross-links. Mechanical properties measurement confirmed the positive influence of polysaccharides on protein film stiffness, and its negative effect on film extensibility. Different ratios of HPMC/SC did not affect film water vapor permeability.

Formulation and Characterization of Double Emulsions Stabilized by Sodium Caseinate–Xanthan Mixtures. Effect of pH and Biopolymer Concentration

Water-in-oil-in-water (w/o/w) double emulsions were stabilized by xanthan gum (XG) in presence of sodium caseinate (SC) using a two-step emulsification process. The evaluation of stability of emulsions was conducted over a period of 20 days. This monitoring was revealed by studying the physicochemical and rheological properties and by optical microscopy observations in combination with granulometry measurements. At natural pH, stability of double emulsions prepared by XG–SC mixture depends on XG concentration. The apparent viscosity of the emulsions increased with the increase of XG concentration. Adjustment of pH of emulsions made with XG–SC near the isoelectric point of the protein improved their stability. At this pH, the viscosity is affected by the XG and SC concentrations. The droplet sizes of double emulsions stabilized by the SC–XG mixture are influenced by the pH and the concentration of two biopolymers. The weight ratio between the two biopolymers in the external aqueous phase has a great influence on the stability of double emulsions formulated at natural pH and pH 5.

The influence of oil droplets on the phase separation of protein–polysaccharide mixtures

A model system consisting of sodium caseinate (SC) + xanthan ± a low volume fraction of oil-in-water emulsion droplets was studied. The phase separation behaviour of xanthan + sodium caseinate was investigated as function of these two variables, followed by experiments on the same systems where oil droplets were introduced. More than 20 mM [Ca2+] was needed to induce phase separation at pH 6.4 and 5.9, but at pH 5.4, phase separation occurred at as low as 5 mM [Ca2+] and a lower concentration of SC or xanthan was required to induce phase separation. An increase in size of sodium caseinate aggregates is proposed as the main factor promoting phase separation. When oil droplets stabilized by sodium caseinate were added to systems containing 0.05–0.1 wt.% xanthan at pH 6.4 this appeared to inhibit significantly the phase separation of the mixtures at [Ca2+] = 22 mM. Simple calculations showed that this effect cannot reasonably be due to excessive accumulation of protein at the droplet surfaces, which is then carried away by the droplets due to creaming. Consequently, a possible mechanism of the inhibition is accumulation of droplets at and strengthening of, the water–water interface of the caseinate–xanthan phase separating entities.

Effects of sodium caseinate concentration and storage conditions on the oxidative stability of oil-in-water emulsions

The oxidative stability of various oils (sunflower, camelina and fish) and 20% oil-in-water (O/W) emulsions, were examined. The mean particle size decreased from 1179 to 325nm as sodium caseinate (emulsifier) concentration was increased from 0.25% to 3% in O/W emulsions (P<0.05). Increasing the microfluidisation pressure from 21 to 138MPa, resulted in a particle size decrease from 289 to 194nm (P<0.05). Emulsified oils had lower detectable lipid hydroperoxide and p-Anisidine values than their corresponding bulk oils (P<0.05). The lipid hydroperoxide and p-Anisidine values of emulsions generally decreased as sodium caseinate concentration increased, and similarly decreased as microfluidisation pressure increased (P<0.05). Increasing storage temperature of the emulsions from 5 to 60°C, resulted in lower detectable lipid oxidation products during storage (P<0.05).

Investigations of the Effects of Xanthan and Sodium Caseinate on the Formation and Stability of an Oil-in-Water Emulsion Stabilized by a Nonionic Surfactant Using a Response Surface Method

Effects of xanthan and sodium caseinate concentrations on the rheological properties and stability of an oil-in water emulsion stabilized by a nonionic surfactant (Tween 20) were investigated. In order to evaluate the influence of component concentrations on the emulsion properties, a response surface method was applied. It was shown by polynomial simulation and modelization of responses of storage modulus and creaming index that in absence of Tween 20, the oily droplets were flocculated by bridging of sodium caseinate macromolecules, when those are insufficient to cover the entire interface. Additionally, it was noted that xanthan reinforces the polymeric network in the aqueous phase when the caseinate is not moved toward the phase. On the other hand, in presence of nonadsorbed caseinate, the polysaccharide develops segregative interactions by thermodynamic incompatibility. These nonadsorbed macromolecules can also flocculate the fatty globules by depletion.

EFFECTS OF EDIBLE SURFACE COATINGS (SODIUM CARBOXYMETHYL CELLULOSE, SODIUM CASEINATE AND GLYCEROL) ON STORAGE QUALITY OF BERANGAN BANANA (MUSA SAPIENTUM CV. BERANGAN) USING RESPONSE SURFACE METHODOLOGY

ABSTRACT Response surface methodology was used to predict the effects and to optimize the concentration of sodium carboxymethyl cellulose (0.1–1.5% w/w), sodium caseinate (0–1% w/w) and glycerol (0–2% w/w) on storage quality of coated Berangan banana (Musa sapientum cv. Berangan). The experimental data could be adequately fitted into a second-order polynomial model with multiple regression coefficients (R2) of 0.787, 0.704, 0.933, 0.786 and 0.886 for the weight loss, firmness, total color difference, total soluble solids content and titratable acidity of coated banana, respectively. The optimum concentrations of sodium carboxymethyl cellulose, sodium caseinate and glycerol for coating banana were predicted to be 1.32, 0.40 and 0.86%, respectively. In general, the sodium caseinate content appeared to be the most significant factor influencing all characteristics of coated banana studied at 26±2C and 40–50% relative humidity. No significant difference between experimental and predicted values verified the accuracy of the response surface models employed. PRACTICAL APPLICATIONS Edible coatings create a modified atmosphere within the fruits and delay their ripening process. Type and concentration of edible coating components contributed in determining the quality (changes in physicochemical characteristics) of coated Berangan banana. Protein and polysaccharide coatings have excellent barrier properties against O2 and CO2. Small amount of additive such as plastisizers like glycerol can improve the appearance of coated fruit and mechanical property of the edible coating. Due to the hydrophobic nature of banana cuticle, addition of emulsifiers such as sodium caseinate can enhance the homogeneity of the edible coating on the banana skin. Therefore, composite edible coatings can successfully be employed as a means to improve the barrier characteristics of edible coatings covering the banana and hence extend its shelf life.

Research on Preparation and Properties of Edible Composite Protein Films

Edible films based on whey protein isolate and sodium caseinate were prepared by uniform design method. Glycerol has been incorporated into the edible films as a plasticizer. For all types of films, the influences of components and forming temperature on film properties, such as mechanical properties, water solubility, optical properties, gas and water vapor permeability were investigated. The results suggested that glycerol was the most important factor influencing all the properties of edible composite protein films. However, both increases of sodium caseinate concentration and glycerol content contributed to decrease the barrier properties of gas and water vapor. Among the films studied, group D (prepared with 5% whey protein isolate, 2% sodium caseinate, 50% glycerol at the temperature of 50 °C) showed moderate mechanical properties, optical properties, water solubility and maximum barrier properties of gas and water vapor, with tensile strength=5.85MPa, elongation=101.20%, transparency=91.4%, gas permeability rate=49.92cm3m-2d-10.1MPa-1and water vapor permeability of 0.128×10-11g m-1s-1Pa-1, 0.260×10-11g m-1s-1Pa-1, 0.513×10-11g m-1s-1Pa-1, 1.252×10-11g m-1s-1Pa-1at the RH gradient of 10-40%, 10-50%, 10-60%, 10-70%, respectively.

Stability of β-Carotene in Protein-Stabilized Oil-in-Water Delivery Systems

Inclusion of liposoluble bioactive compounds in fortified foods represents a complex challenge due to the labile nature of such compounds and the instability of oil-in-water emulsion-based delivery systems. In the present study, dispersions prepared with 10% (w/w) sunflower oil (SO) or hydrogenated palm kernel oil (HPKO) containing 0.05% (w/w) β-carotene were stabilized by various concentrations of whey protein isolate (WPI) or sodium caseinate (NaCas) (0.1 to 2.0% w/w) in 30% (w/w) sucrose aqueous solutions. Physicochemical characterization of emulsions was done considering the particle size, the particle surface protein coverage, and the physical state of continuous and dispersed phases. Physical stability of the systems and their protection properties on β-carotene were compared. The lipid carrier type and interfacial structure were investigated as the two key factors which regulate the stability of labile lipophilic bioactive molecules in food model systems. Our results showed high β-carotene stability when O/W systems were stable (protein concentration ≥0.8% w/w.) A (partially) solid lipid carrier (HPKO) enhanced protection compared to the liquid carrier (SO) as the bioactive molecules were entrapped in isolated domains within the solid lattice and kept apart from reactive species in the surroundings. NaCas provided a better barrier than WPI due to the different amino acid composition and interface structure which significantly reduced β-carotene degradation rate.

Development of multiple emulsions based on the repulsive interaction between sodium caseinate and LBG

The stability of oil-in-water, water-in-water and multiple emulsions containing sodium caseinate (Na-CN) and/or locust bean gum (LBG) at pH 5.5 was investigated with different compositions using a visual analysis (creaming and/or phase separation), optical microscopy and rheological measurements. Oil-in-water emulsions (O/W) were produced by high pressure homogenization, which promoted the formation of very small droplets (∼0.4 μm) and hindered the destabilization process. In the second step of this study, a visual phase diagram was constructed in order to identify the concentrations of sodium caseinate (Na-CN) and locust bean gum (LBG) that led to phase separation at pH 5.5. A mixed solution composed of 3% (w/v) Na-CN and 0.3% (w/v) LBG was chosen to produce the water-in-water and multiple emulsions. After centrifugation, the solution was separated into an upper phase rich in polysaccharide (PS) and a bottom phase rich in protein (PR), which were mixed in different proportions (1:3, 1:1, 3:1), forming the water-in-water (W/W) emulsions. The stability, microstructure and rheological properties of the W/W emulsions depended strongly on the composition of the biopolymers. An increase in the polysaccharide concentration in the W/W emulsions led to the production of more viscous and stable systems. Multiple emulsions with different characteristics were prepared and also depended on the biopolymer composition. The system with the highest polysaccharide content was the only one that showed an O/W/W structure, while the others presented the microstructure of an O/W-W/W emulsion.

Factors Influencing Formation and Properties of Nanoemulsion Stabilized by Sodium Caseinate and Tween 80

In this study formation and properties of o/w emulsion stabilized by a mixture of sodium caseinate (2, 5 and 10 wt %) and non-ionic emulsifier Tween 80, sorbitan mono-9-octadecenoate, (0, 0.5, 1 and 1.5 wt %) were investigated at various pH values(3, 5 and 7) and calcium ion concentrations (0, 0.2, 0.4 and 0.6 wt%). Emulsion samples were prepared by using a sonicator with a nominal power output of 750 W and an operating frequency of 20 kHz. Sonication of samples was carried out in a temperature-controlled chamber at a constant temperature of 20 oC and the highest acoustic power available for 3 minutes. The results showed that increasing the concentration of sodium caseinate and Tween 80 generally reduced the size of droplets, although it was observed that Tween80 adversely affected the size of droplets at higher concentration under acidic conditions. Moreover, pH and calcium ion significantly affected the diameter and specific surface area of droplets (p<0.05). The smallest droplets formed in the absence of calcium ion, and at pH = 7, 10% sodium caseinate and 1% Tween 80. It was found that the size of droplets grew in the presence of calcium ion. However, at very low concentration of calcium ion the increase in the size of droplets was insignificant (p<0.001). Keywords: Nanoemulsion, Sodium caseinate, Tween 80, Ultrasound

Stability of emulsions formulated with high concentrations of sodium caseinate and trehalose

Abstract Stability of emulsions formulated with 10 wt.% oil (concentrated fish oil, CFO, sunflower oil, SFO, or olive oil, OO), sodium caseinate concentrations varying from 0.5 to 5 wt.%, giving oil-to-protein ratios of 20–2, and 0, 20, 30 or 40 wt.% aqueous trehalose solution was studied by Turbiscan. Particle size distribution, microstructure, and small angle X-ray scattering (SAXS) patterns were also obtained. The main mechanism of destabilization in a given formulation strongly depended on oil-to-protein ratio. As evidenced by the BS -profile changes with time, emulsions formulated with 0.5 and 1 wt.% NaCas destabilized mainly by creaming while for the 2 wt.% NaCas concentration, both creaming and flocculation mechanisms, were involved. The main destabilization mechanism for the 3, 4 or 5 wt.% NaCas emulsions was flocculation. Stability of emulsions was also affected by the content of trehalose in the aqueous phase. Trehalose diminished the volume-weighted mean diameter ( D 4,3 ) and greatly improved stability.

The effect of transglutaminase from Streptomyces sp. CBMAI 837 on the gelation of acidified sodium caseinate

The influence of the transglutaminase (TG) from a newly isolated Brazilian Streptomyces sp. CBMAI 837 and sodium caseinate concentration (4% and 8%, w/w) on acid-gel properties was studied. Standard gels with and without commercial transglutaminase samples were tested in parallel. The mechanical properties of the samples (stress and strain at rupture and elasticity modulus) were evaluated using uniaxial compression measurements. Texture parameters showed that the commercial TG gels had greater values of elasticity modulus, while addition of the Streptomyces sp. CBMAI 837 TG to the gel led to the formation of less elastic, but more deformable gels. The electrophoresis results showed that the commercial TG enzyme in this system promoted higher molecular mass protein polymers than the enzyme from Streptomyces sp. CBMAI 837. Microscopy and water-holding capacity (WHC) observations showed that all the gel characteristics could be associated with specific interactions promoted by each TG tested.

Impact of Sodium Caseinate Concentration and Location on Magnesium Release from Multiple W/O/W Emulsions

Water-in-oil-in-water (W/O/W) double emulsions were prepared and the rate of release of magnesium ions from the internal to the external aqueous phase was followed. Sodium caseinate was used not only as a hydrophilic surface-active species but also as a chelating agent able to bind magnesium ions. The release occurred without film rupturing (no coalescence). The kinetics of the release process depended on the location (in only one or in both aqueous compartments) and on the concentration of sodium caseinate. The rate of release increased with the concentration of sodium caseinate in the external phase and decreased when sodium caseinate was present in the inner droplets. The experiments were interpreted within the frame of a mean-field model based on diffusion, integrating the effect of ion binding. The data could be adequately fitted by considering a time-dependent permeation coefficient of the magnesium ions across the oil phase. Our results suggested that ion permeability was influenced by the state of the protein interfacial layers which itself depended on the extent of magnesium binding.

Rheological Behavior of High‐Concentration Sodium Caseinate Dispersions

Apparent viscosity and frequency sweep (G', G'') data for sodium caseinate dispersions with concentrations of approximately 18% to 40% w/w were obtained at 20 degrees C; colloidal glass behavior was exhibited by dispersions with concentration >or=23% w/w. The high concentrations were obtained by mixing frozen powdered buffer with sodium caseinate in boiling liquid nitrogen, and allowing the mixtures to thaw and hydrate at 4 degrees C. The low-temperature G'-G'' crossover seen in temperature scans between 60 and 5 degrees C was thought to indicate gelation. Temperature scans from 5 to 90 degrees C revealed gradual decrease in G' followed by plateau values. In contrast, G'' decreased gradually and did not reach plateau values. Increase in hydrophobicity of the sodium caseinate or a decrease in the effective volume fraction of its aggregates may have contributed to these phenomena. The gelation and end of softening temperatures of the dispersions increased with the concentration of sodium caseinate. From an Eldridge-Ferry plot, the enthalpy of softening was estimated to be 29.6 kJ mol(-1). The results of this study should be useful for creating new products with high concentrations of sodium caseinate.

Rheological Properties and Phase Separation of Xanthan-Sodium Caseinate Mixtures Analyzed by a Response Surface Method

Effects of xanthan and sodium caseinate concentrations on the rheological properties of their mixture in an aqueous medium were investigated at neutral pH. It was deduced from the use of an experimental design methodology, the existence of a critical concentration of sodium caseinate, which depends on the xanthan quantity, and beyond which repulsive segregation interactions occur, generating a weakening of the elastic modulus and an embitterment of the colloidal system structure. In addition, it was observed that when the Casson viscosity value of the aqueous solution was above 0.1 Pa.s, phase separation of the system was observed. The phase diagram of the solution was established using a polynomial fit.

Interactions between sodium caseinate and LBG in acidified systems: Rheology and phase behavior

The behavior of model systems formed by different concentration of sodium caseinate and locust bean gum (LBG) was investigated using confocal microscopy (CSLM) and rheological measurements in order to determine the interaction between these two ingredients in acidified dairy products. A visual phase diagram was constructed at different biopolymer concentrations and four different types of systems were observed for the mixtures in the isoelectric point of protein: one-phase gels (G1P), two-phase gels (G2P), one-phase liquid mixtures (L1P) and two-phase liquid mixtures (L2P). These different systems resulted from the different kinetics of phase separation and gel formation. The one-phase systems (gels and liquid mixtures) showed a micro-phase separation when visualized by CSLM, although they were homogeneous at macroscopic level. In a general way, the micro or macro phase separation led to a biopolymer concentration on separated phases, resulting in an increase of the stress at fracture for the gels or the viscosity for the liquid mixtures. However, the behavior of the whole system did not correspond to the sum of the mechanical properties of separated phases.

Influence of ageing time on sodium caseinate gelation induced by glucono-δ-lactone at different temperatures

The aim of this work was to study the influence of a wide range of incubation tem peratures (4 to 40 °C) and sodium caseinate concentrations (2 to 6% (w/w)) on acid-gel properties during and after long ageing times, formed under different acidification rates promoted by gradual hydrolysis of glucono-δ-lactone (GDL) into gluconic acid. The kinetics of acidification and gelation were followed from pH 6.7 to a final pH value around 4.6 by evaluation of the pH and mechanical properties using uniaxial compression measurements (stress and strain at rupture). As a general trend, faster acidification rates led to faster gel network formation, and lower incubation temperatures led to a higher final pH, while increasing caseinate concentration promoted a small increase in the pH value. Stress at rupture of gels induced by fast acidification rates did not exhibit a weaker gel network, showing the contribution of rearrangements of the network gel at final pH to the electrostatic balance, besides the fact that the hydrophobic interactions and hydrogen bonds were important forces involved in microstructure stabilization. Rearrangement of the gel network was mainly observed at pH values close to 4.6 and was more pronounced at longer ageing times of incubation. The stronger gels were obtained at incubation temperatures of 10 °C followed by 25, 4 and 40 °C, which was an indication of the behavior of the gel network microstructure, since at the highest temperature the pores were larger and syneresis more pronounced. The results of this study suggest that the incubation temperature, protein concentration and rearrangement at final pH have a great influence on the balance between the attractive and repulsive forces between protein and water, contributing to development of optimized texture and water-holding capacity of acid-gels of sodium caseinate.