Sodium Carboxymethyl Cellulose Concentration Research Articles

Research by choice of excipients ingredients of the gel for the therapy of radiation lesions of the skin based on rheological studies

The aim of this work is to conduct a research analysis of changes in the structural and mechanical properties of the gel from the addition of active substances and surfactants.
 Materials and methods. In the presented work, model samples of the gel with active substances were studied: freshly obtained stonecrop juice, sea buckthorn oil, rosehip oil, St. John's wort oil and quercetin. As substances for the manufacture of bases hydrocolloids of cellulose derivatives were used: sodium carboxymethylcellulose (NaCMC) and hydroxyethylcellulose (HEC) with a surfactant Lanette SX.
 A study of the rheological properties of the samples was performed using a rheoviscometer Rheolab QC (Anton Paar, Austria) using a system of coaxial cylinders C-CC27 / SS. The Rheolab QC rheometer is equipped with RheoPlus software, which allows you to set the necessary experimental conditions (shear rate gradient range, number of measuring points and measurement time of one point).
 Results. The rheological properties of model samples of NaCMC and HEC gels, depending on the used concentration, were studied. With increasing concentrations of both NaCMC and HEC thixotropy of dispersed systems decreases. The change of structural and mechanical parameters of hydrogels from the addition of active ingredients and surfactant is analyzed, and established that adding them into the hydrogels increases the structural and mechanical parameters of model samples.
 A study of gels with a constant concentration of sodium carboxymethylcellulose and hydroxyethylcellulose and different content of surfactant Lanette SX established that as the surfactant concentration increases, the area of the hysteresis loop and the resistance of the dispersed system to the applied mechanical fracture increase.
 Conclusions. According to the results of the obtained structural and mechanical parameters and rheograms of the studied model samples of gels, it is rational to use in further studies of sodium carboxymethyl-cellulose (1.5 %) and hydroxyethylcellulose (1.25 %) stabilized Lannete SX in concentrations of 4-5 % and 3-5 % respectively

Investigation of aggregation behavior and surface properties of cationic surface-active ionic liquids and sodium carboxymethylcellulose mixed systems

Abstract The impact of different concentrations of sodium carboxymethyl cellulose (NaCMC) on the micellization process in cationic, ester-functionalized, ethyl-substituted imidazolium-based surface-active ionic liquids (SAILs) ([C n Eeim]Br where, n = 12, 14, 16) were investigated using specific conductivity and surface tension measurements at 298 K. The study focused on determining the critical micelle concentration (CMC) of the three pure SAILs and their mixtures with NaCMC to evaluate various thermodynamic and interfacial parameters. The results showed that the CMC values decreased significantly with increasing hydrophobicity of the SAILs, while the CMC increased with a gradual increase in the NaCMC mole fraction in the SAIL–NaCMC mixed systems. It was observed that the excess free energy of micellization ( ∆ G e x m ${{\increment}G}_{ex}^{m}$ ) and the minimum free energy of surface at equilibrium ( ∆ G min s ${{\increment}G}_{\mathrm{min}}^{s}$ ) exhibited an opposite behaviour, indicating that the formed mixed micelles were stable while the formed surface was unstable. The results of this study are useful for evaluating the properties of SAIL–NaCMC mixed systems to improve and better understand their applications in the food, medical and cosmetic industries.

Development and In-vitro Effectiveness of Tooth-gel containing Herbal Extracts

The aim of the current research was to formulate and evaluate herbal extracts tooth gel of of Emblica officinalis, Terminalia bellirica, Terminalia chebula, Trachycpermum ammi, Embelia ribes and Syzygium aromaticum, which are used for oral hygiene, plaque control, gingivitis, anti-bacterial, astringent and prevent tooth decay. Powders were extracted separately and further evaluated for phytochemical screening which showed presence of phytoconstituents like alkaloids, tannins, flavonoids and carbohydrates. A 23 factorial design was used to optimize tooth gel using independent variables: concentration of sodium carboxymethyl cellulose (X1) (2 and 3 %); concentration of Gantrex (X2) (0 and 1%) and concentration of sodium lauryl sulphate (X3) (1.5 and 2.5 %) and dependent variables foaming capacity (Y1) and zone of inhibition (Y2). Tooth gel was evaluated for color, odor, taste and pH. Gel exhibited good viscosity, extrudability, spreadability and antimicrobial activity. Formulation F5 showed highest foamability (48.2±0.4ml) and zone of inhibition (4.4±0.2cm) with the desirability value 1 (most desirable response) at design space X1 = 2%, X2 = 0%, X3 = 2.5 % and was therefore considered optimize formulation. Formulation was found stable after 3 months of stability studies. Thus, formulated toothgel had better results when compared with marketed formulation. In conclusion, formulated toothgel was considered as helpful to take care of oral hygiene of human being.

Terahertz Absorption Characteristics of the Sodium Carboxymethyl Cellulose Colloid Based on Microfluidic Technology

Sodium carboxymethyl cellulose is a type of macromolecular chemical substance that is widely used in the industry for food thickening. In this study, terahertz and microfluidic technologies were combined, and a microfluidic chip with a channel depth of 50 μm was fabricated to carry samples. The terahertz characteristics of the sodium carboxymethyl cellulose colloid were studied at different concentrations and applied electric fields. The obtained results showed that different concentrations of sodium carboxymethyl cellulose have different time-domain spectra; with an increase in concentration, the terahertz transmittance of sodium carboxymethyl cellulose decreased. Under the applied electric field treatment, the longer the electric field acting time is, the higher the terahertz transmission intensity is. This approach is a safe and reliable new method for the determination of sodium carboxymethyl cellulose concentration, which provides technical support for the in-depth study of sodium carboxymethyl cellulose.

Fouling characterization of calcium carbonate on heat transfer surfaces with sodium carboxymethyl cellulose as an inhibitor

Fouling via the deposition of calcium carbonate (CaCO3) on heat transfer surface reduces the heat transfer efficiency and compromises the stable operation of the heat exchanger. Sodium carboxymethyl cellulose (SCMC) as a fouling inhibitor effectively prevents the growth of CaCO3. In this work, the fouling characteristics of a heat transfer surface by CaCO3 with the SCMC inhibitor were studied experimentally; the effects of the SCMC concentration, inlet temperature of the solution, mass flow, SCMC degree of substitution, and SCMC viscosity on fouling inhibition were investigated. Moreover, the asymptotic fouling thermal resistance and fouling inhibition efficiency were analyzed by varying the operation conditions and the physical properties of SCMC. The results show that the fouling thermal resistance decreases with increasing SCMC concentration, degree of substitution, and solution temperature, and increases with increasing mass flow of the solution. However, the effects of the SCMC viscosity varying from 600 mpa⋅s to 15000 mpa⋅s on fouling thermal resistance were observed to be negligible. Additionally, there was significant variation of the CaCO3 fouling morphology with a change from calcite particle to an irregular sphere after the addition of inhibitor.

Effect of Rheological Properties of Aqueous Solution of Na-CMC on Spray Angle for Conical Pressure-Swirl Atomizers

Aerosol is a multiphase system, created as a result of the dispersion of a liquid in a gaseous medium. The atomized liquids are most often water and fuel; however, they can be any other substance. Even a small addition of a substance that changes the rheological properties (i.e., the nature of the flow) can change the properties of the resulting aerosol. The most important parameters that characterize the aerosol are the outflow rate, the droplet diameter, the spray spectrum, and the spray angle. The latter is important when selecting atomizers, especially those working in groups on the sprayer boom. The spray angle is an important parameter of the atomization process, providing a great deal of information about the quality of the spray. This study presents the results of rheological tests and the atomization of aqueous solutions with varying concentrations of sodium carboxymethylcellulose (Na-CMC). We found that the spray angle decreased with increasing Na-CMC concentration in the solution, which is attributable to an increase in shear viscosity. The design of the atomizer is also important. The largest spray angles were obtained for an atomizer with a diameter of 0.02 m and with the inlet port being placed at an angle to the atomizer axis. Based on the experimental results for various liquids and atomizer designs, a correlation equation describing the spray angle is proposed.

Study of the effect of the concentration of sodium carboxymethylcellulose on hemostatic and antiadhesive activity during liver operations in an experiment

Liver surgeries are associated with the risk of bleeding and the development of adhesive disease. Sodium carboxymethylcellulose (Na-CMC) forms an elastic swelling gel and a “lattice” that holds the blood cells.The aim: determine the concentration of Na-CMC, which has the maximum hemostatic and anti-adhesive effect, during liver surgeries in the experiment.Materials and methods. The coagulating effect of Na-CMC (from 0.5% to 9%) was studied in vitro. In vivo experiment on 167 male Wistar rats weighing 185–250 g studied the bleeding time and the amount of blood loss, anti-adhesive activity in the model of liver surgery by cutting off the edge of the organ in the standard way: the depth and width of the wound is 1 cm; the height is 3 mm.Results. In vitro the minimum coagulating effect was obtained in 3% of Na-CMC. In vivo the maximum effect on reducing the bleeding time (–46% compared to the control, p < 0.01) and the amount of blood loss (–27% compared to the control, p < 0.01) had 6% Na-CMC. Then, according to the degree of decrease in the bleeding time, there were: 5% Na-CMC (–40%), 4% Na-CMC (–37%), 3% Na-CMC (–29%), 7% Na-CMC (–27%), 8% Na-CMC (–11%). For the amount of blood loss, a similar pattern of decreasing effect was observed: 5% Na-CMC (–21%), 4% Na-CMC (–14%), 7% Na-CMC (–12%), 3% Na-CMC (–11%), 8% Na-CMC (–5%). When comparing all the studied concentrations of Na-CMC gel with the control group in terms of bleeding time and blood loss, the differences are statistically significant: p < 0.01. Maximum anti-adhesive activity was observed for 6% Na-CMC on days 7 and 14 after surgery: the adhesive process was estimated at 0.497 [0.000–0.497] and 0.962 [0.000–1.301] points vs. 2.457 [2.118–2.457] and 4.071 [3.758–4.602] points in the control group (p < 0.01).Conclusion. The maximum hemostatic and anti-adhesive effect has 6% Na-CMC.

Influence of hydrophobic and electrostatic interactions on counterion-dissociation in sodium carboxymethylcellulose - polyethylene glycol (PEG) solutions

Counterion dissociation/condensation and related phenomena of sodium carboxymethylcellulose have been investigated in water with varying hydrophobicity by conductance measurements. Alteration of the hydrophobicity of the media was accomplished by adding varying amounts of polyethylene glycol with different molar masses to the solutions. Analyses of the specific conductances measured as a function of sodium carboxymethylcellulose concentration were performed taking into account the de Gennes scaling model which describes the configuration of polyion chains in semidilute solutions. Results indicate that polyions are the chief transporter of the electricity in the investigated solutions and that a major fraction of the counterions is accompanied by the polyion chains and performs concerted movement towards the positive electrode. Increasing molar mass of the polyethylene glycol samples added to aqueous sodium carboxymethylcellulose solutions containing a given amount of the additive promotes counterion-dissociation, whereas increasing amount of the additive with a given molar mass promotes counterion-condensation. Relative influences of electrostatic and hydrophobic forces have been taken into consideration in order to elucidate the observed dissociation/condensation behavior of counterions of aqueous sodium carboxymethylcellulose solutions. Analyses of the results provided important insight regarding the possible alterations of the conformation of the polyions originating from the subtle balance of hydrophobic and electrostatic interactions in these solutions.

An adhesive-aided ring spinning for improving cotton yarn quality with the aid of sodium carboxymethyl cellulose solution

An adhesive-aided ring spinning was developed to improve cotton yarn quality through the wetting and adhesion effect of an adhesive solution, namely, sodium carboxymethyl cellulose solution on fibrous strand in yarn formation zone during spinning process. The spinning mechanism of the adhesive-aided ring spinning with sodium carboxymethyl cellulose solution was analyzed, and the effects of two factors, that is, speed ratio (the ratio of the linear surface velocity to the output speed) and sodium carboxymethyl cellulose concentration, on the yarn performance are investigated. The experiment results reveal that the adhesive-aided ring spinning with sodium carboxymethyl cellulose concentration of 0.7% can significantly reduce yarn hairiness indicated by the hairiness S3 value reducing to 69% and still showing a prominent reduction (65%) after winding process. It has been found that a slightly faster linear surface velocity of the cylinder of the adhesive-aided ring spinning compared with the output speed of the yarn is more beneficial to the reduction of yarn hairiness S1+2 value. Meanwhile, the higher sodium carboxymethyl cellulose concentration also contributes to a higher breaking strength (increasing from 18.24 to 21.12 cN/tex) and lower breaking elongation (reducing from 4.98% to 4.08%). The abrasion resistance of adhesive-aided ring spun yarns also shows an obvious improvement of 12.8%. Therefore, the newly developed adhesive-aided ring spinning with the sodium carboxymethyl cellulose solution provides an effective method to enhance the quality of cotton yarns.

Effects of sodium carboxymethyl cellulose on rheological properties and gelation behaviors of sodium alginate induced by calcium ions

Different concentrations of sodium carboxymethyl cellulose (CMC) were added into 1.0 g/100 g sodium alginate to investigate the rheological properties and gelation behaviors of the composite gel. Gluconic acid-δ-lactone (GDL) was used to release Ca2+ ions to induce uniform gel formation by sodium alginate. The effects of CMC on critical gelation behavior during sodium alginate gelation were discussed. The sodium alginate/CMC composite gel is still a shear thinning fluid, and its viscosity is positively related to CMC content. When CMC content is higher than 0.4 g/100 g, the composite viscosity (η*) differs from the apparent viscosity (η), and η* remains at higher level than η. When CMC content is lower than 0.2 g/100 g, the gelation of sodium alginate accelerates, and the gelation strength increases. However, when CMC content is higher than 0.4 g/100 g, the gelation accelerates, but the gelation strength decreases with increasing CMC. The gel point of sodium alginate (ƒgel) is delayed with increasing CMC. The critical exponent differs greatly when CMC content is higher than 0.2 g/100 g, and the system loses self-similarity at the gel point. The fractal dimension of the composite gel increases initially and then decreases with increasing CMC. The system develops the densest structure at 0.4 g/100 g CMC content.

Inhibition of calcium carbonate fouling on heat transfer surface using sodium carboxymethyl cellulose

Inhibition of calcium carbonate (CaCO3) fouling using sodium carboxymethyl cellulose (SCMC) was investigated in this study, focusing on the effect of the SCMC concentration on the fouling characteristics of CaCO3 on the stainless steel surface. The fouling characteristics were investigated via pH displacement method, electrochemical impedance spectroscopy, and dynamic experiment analysis. The experimental results indicated that these three methods provided a consistent conclusion: SCMC exhibited a promising performance of fouling inhibition, and the inhibition efficiency and induction period of CaCO3 fouling increased with increasing SCMC concentration ranging from 50 to 200 mg L−1. The inhibition efficiency reached 93.2% for SCMC concentration of 200 mg L−1. Scanning electron microscopy images of CaCO3 fouling changed from irregular slender needles and clusters to small chips with the addition of SCMC. Moreover, a protective film was formed on the stainless steel surface by adsorption of the constituent of SCMC in the presence of SCMC, directly preventing the deposition of CaCO3 fouling on stainless steel surface.

Mechanical Strength Properties of Injectable Carbonate Apatite Cement with Various Concentration of Sodium Carboxymethyl Cellulose

Mechanical strength is one of the key factors for clinical application of injectable carbonate apatite (CO3Ap) cement. Incorporation of polymeric additives into the mixing liquid of injectable bone cement has been known to improve cement injectability. The aim of this study is to determine whether incorporation of sodium carboxymethyl cellulose (Na CMC) into the mixing liquid would affect the diametral tensile strength (DTS) of injectable CO3Ap cement. In the present study, Na CMC, a polymeric additive and a cellulose derivative, was used to promote the injectability of CO3Ap cement. Three groups of CO3Ap cement samples consist of CaCO3 and CaHPO4 powder in each group were mixed with 0.5 %, 1%, and 2% Na CMC solution incorporated to 0.2 mol/L Na2HPO4 solution. As a control, powder mixed with 0.2 mol/L Na2HPO4 solution was used. Samples were kept in an incubator (37°C, 100% relative humidity, 24 hours). The mechanical strength properties were evaluated by diametral tensile strength (DTS). The average DTS of samples containing 0.5%, 1%, and 2% Na CMC were 3.19 MPa, 3.57 MPa, and 3.06 MPa, respectively. While the average DTS of the control group was 3.29 MPa. The groups containing Na CMC in all concentrations showed no statistical difference (p>0.05) on DTS compared to the control group. The injectability improved as the concentration of Na CMC increased. In conclusion, revealed that Na CMC does not affect the mechanical strength of CO3Ap cement. Therefore, it may be considered as an effective material to promote cement injectability. Further study of additives that can be used to promote the injectability of CO3Ap cement and enhance the mechanical strength awaits based on this initial finding.

Superabsorbent Polymer Based on Sodium Carboxymethyl Cellulose Grafted Polyacrylic Acid by Inverse Suspension Polymerization

A superabsorbent polymer (SAP) based on graft copolymerization of sodium carboxymethyl cellulose and acrylic acid was prepared by inverse suspension polymerization using potassium persulfate as an initiator and N,N′-methylenebisacrylamide as a cross-linker. Experiments were performed at 70°C for 90 min but varying the concentrations of sodium carboxymethyl cellulose (NaCMC), acrylic acid (AA), potassium persulfate (KPS), and N,N′-methylenebisacrylamide (MBA), and also varying % neutralization of AA. The maximum swelling capacity for SAP was 544.95 g/g in distilled water and 44.0 g/g in 0.9% w/v NaCl solution. This near optimal SAP was prepared using 2.0 g/100 mL NaCMC, 1.0 mol/L AA with 70% neutralization, 0.014 mol/L KPS, and 0.01 mol/L MBA.

Surface modification of poly(D,L-lactic-co-glycolic acid) nanoparticles using sodium carboxymethyl cellulose as colloidal stabilize.

Poly(D,L-lactic-co-glycolic acid) nanoparticles (PLGA NPs) have been widely used as drug delivery systems for both small molecules and macromolecules. However, the colloidal stability problem remains unsolved. This study aims to investigate the possibility of using sodium carboxymethyl cellulose (SCMC) as a stabilizing agent of PLGA NPs. In this study, PLGA NPs were fabricated using various concentrations of SCMC (0.01, 0.1 and 0.5% w/v) by solvent displacement method. SCMC coated NPs were characterized using DLS, FTIR, DSC, colorimetric method. Particle size, polydispersity index, zeta potential values and SCMC adsorption increased with SCMC concentration. FTIR spectra, DSC thermograms and results of colorimetry suggested the interaction of SCMC and PLGA NPs. The stability of SCMC coated PLGA NPs was observed during the storage of three weeks in water. The stability of SCMC coated NPs in serum was also evaluated. Cell viability study revealed that there was no toxicity increased when SCMC was used as a stabilizing agent up to a concentration of 0.1% w/v. SCMC coated PLGA NPs bound A549 cells in a time dependent manner and with a greater extent than uncoated PLGA NPs. In conclusion, SCMC can be used to stabilize PLGA NPs by adsorbing on the surface of NPs.

Formulation optimization of gastroretentive drug delivery system for allopurinol using experimental design

Objectives: The objective of the study was to develop gastroretentive dosage form (GRDF) for allopurinol (ALP) using combined approaches of mucoadhesion and floating systems. GRDF was systematically optimized using 32-full factorial design.Methods: Concentrations of sodium carboxymethyl cellulose (X1) and concentration of polyoxyethylene oxide WSR 303 (X2) were selected as independent variables, whereas gastroretentive parameters like total floating time (TFT) (Y1), mucoadhesive force (MF) (Y2), time required for 10% drug release (Y3) and time required for 80% drug release (Y4) were selected as dependent variables in development of robust GRDF of ALP. GRDF was evaluated for gastroretentive parameters such as floating lag time (FLT) and TFT, MF using texture analyzer and ex vivo residence time using modified disintegration test apparatus. Roentgenography study of optimized formulation was conducted to evaluate in vivo gastro retentive behavior using albino rabbits.Results: Developed tablets showed immediate in situ gas generation and exhibited FLT of 1.68 s after placing into simulated gastric fluid, which lead to buoyancy as well as controlled drug release for 24 h with zero-order drug release kinetics. The optimized formulation was selected based on in vitro drug release characteristics. In vivo retention of optimized formulation was corroborated using roentgenography studies.Conclusion: The study concluded that the combination of mucoadhesive and floating approaches for GRDF aids to achieve desired gastroretentive performance and drug release properties for ALP. The formulation scientists may adopt these formulation strategies for drugs suitable for the development of GRDF.

In vitro Effect of Aqueous Extract of Fresh Leaves of Abroma augusta L on the Diffusion of Glucose

There have been a number of reports concerning the role of dietary fiber in hampering the diffusion of glucose and lowering the postprandial serum glucose. The present study investigates the effect of viscous aqueous leaf extract of Abroma augusta L (Family: Sterculiaceae, Bengali name: Ulatkambal, English name: Devil's cotton, DC) on the diffusion of glucose in vitro. Different mixtures were prepared using varying concentrations of sodium carboxymethylcellulose (Na-CMC) and aqueous extract of A. augusta with a fixed concentration of glucose. The diffusion of glucose from these systems into the outer medium through the ultra-fine membrane was measured. The results showed that both Na-CMC and aqueous extract of ulatkambal significantly (p<0.05) reduced the diffusion of glucose compared to control in a concentration-dependent manner. The result of this study suggested that dietary fiber present in the aqueous leaf extract of A. augusta may be potentially effective in the management of type 2 diabetes mellitus by reducing post-prandial glucose absorption from the gastrointestinal tract. DOI: http://dx.doi.org/10.3329/bpj.v16i1.14486 Bangladesh Pharmaceutical Journal 16(1): 21-26, 2013

Pd–sodium carboxymethyl cellulose nanocomposites display a morphology dependent response to hydrogen gas

Hydrogen reduction of H2PdCl4 in the presence of sodium carboxymethyl cellulose (SCMC) in dynamic thin films on a microfluidic spinning disc platform affords Pd–SCMC nano-structures. The morphology of Pd nanocomposites changed from well-connected nano-rosettes to disconnected agglomerates with an increase in SCMC concentration. These nanocomposites were drop cast on interdigitated electrodes (IDEs) to afford sensors for hydrogen gas, with a decrease and increase response in current for nano-rosettes and agglomerates structures, respectively.

Formulation Optimization and Characterization of Spray Dried Microparticles for Inhalation Delivery of Doxycycline Hyclate

The local delivery of antibiotics in the treatment of infectious respiratory diseases is an attractive alternative to deliver high concentration of antimicrobials directly to the lungs and minimize systemic side effects. In this study, inhalable microparticles containing doxycycline hyclate, sodium carboxymethylcellulose, leucine and lactose were prepared by spray drying of aqueous ethanol formulations. Box-Behnken design was used to study the influence of various independent variables such as polymer concentration, leucine concentration, ethanol concentration and inlet temperature of the spray dryer on microparticle characteristics. The microparticles were characterized in terms of particle morphology, drug excipient interaction, yield, entrapment efficiency, Carr's index, moisture content, thermal properties, X-ray powder diffraction, aerosolization performance and in vitro drug release. The effect of independent variables on spray dryer outlet temperature was also studied. The overall shape of the particles was found to be spherical like doughnuts in the size range of 1.16-5.2 µm. The optimized formulation (sodium carboxymethylcellulose concentration 14% w/v, leucine concentration 33% w/v, ethanol concentration 36% v/v, inlet temperature of 140°C) exhibited the following properties: yield 56.69%, moisture content 3.86%, encapsulation efficiency 61.74%, theoretical aerodynamic diameter 3.11 µm and Carr's index 23.5% at an outlet temperature 77°C. The powders generated were of a suitable mass median aerodynamic diameter (4.89 µm) with 49.3% fine particle fraction and exhibited a sustained drug release profile in vitro.

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.

Rheological properties of carboxymethyl cellulose (CMC) solutions

In this study, we investigated the way of predicting two critical concentrations of sodium carboxymethyl cellulose (CMC) solutions using simple experimental procedures with a rotational rheometer. It was found that, above a critical shear rate, all CMC solutions (0.2 to 7 wt.%) exhibit shear-thinning behavior and the flow curves could be described by the Cross model. A first critical CMC concentration c*, transition to semidilute network solution, was determined using the following methods (1) study of the flow curve shapes, (2) Cross model parameters, (3) plot of the specific viscosity vs the overlap parameter, and (4) empirical structure–properties relationships. Furthermore, both creep and frequency-sweep measurements showed that the solutions behaved as viscoelastic materials above a second critical CMC concentration c** (transition to concentrated solution). The characterization of CMC solutions was completed with a time-dependent viscosity study that showed that the CMC solutions exhibited strong thixotropic behavior, especially at the highest CMC concentrations.