Carboxymethyl Cellulose Concentration Research Articles

Combination of carboxymethylcellulose and wood hemicelluloses to enhance encapsulation efficiency and microcapsule wall thickness

Wood hemicelluloses have been used as a wall material for spray-dried microencapsulation of polyphenols. Nevertheless, their incomplete water solubility could negatively impact their encapsulation efficiency (EE) and the formation of a complete protective layer, which might be alleviated synergistically by combining them with carboxymethylcellulose (CMC). Here, we explored the effects of CMC addition (0.5–3.0 %, w/w of WM) on the capacity of galactoglucomannans (GGM) and glucuronoxylans (GX) to retain bioactive compounds of bilberry during spray drying; and its contribution to the formation of wall thickness. The results revealed that EE of GGM and GX increased by 4–8 % with the CMC addition at 0.5 %, but significantly declined at higher CMC concentrations. Adding CMC improved the microcapsules' antioxidant activities, surface smoothness, and solubility, but had no effect on their particle size, thermal properties, amorphous structure, or moisture content. The majority of the GGM and GX microcapsules had a hollow internal structure surrounded by continuous wall matrix with a thickness of about 2.3–2.6 μm, which increased to 3.1–3.5 μm with the addition of 0.5 % CMC. Therefore, using CMC at an optimized proportion as a co-encapsulant improved wood hemicelluloses' ability to protect bioactive compounds during spray drying and enhanced microcapsule wall formation.

Effects of carboxymethyl cellulose concentration on mechanical, viscoelastic properties, and thermal properties of starch/plant fiber foaming tableware materials with foam structure

In this study, a novel bio-based composite of starch/plant fiber foaming tableware material was prepared by the hot-pressing foaming method. The influence of the content of carboxymethyl cellulos (CMC) as a new type of film-forming agent filler on the properties of foam materials was systematically investigated. The results showed that the foam material with 10 wt% CMC had excellent cell morphology and uniform cell size (the average cell size reached the minimum value of 465.7 μm), relatively high porosity (57.01%), and excellent thermal insulation properties (thermal conductivity: 0.0541 W/m·K). The tensile strength of foam increased from 4.289 MPa for 0 wt% CMC to 5.714 MPa for 10 wt% CMC loading. Similarly, the flexural strength also increased from 11.609 MPa to 15.719 MPa for the foam material with 10 wt% CMC. The thermal stability and viscoelastic properties of the foam material reached the highest after adding 10 wt% CMC. In addition, the increase of CMC content is beneficial to improve the oil resistance and biodegradability of the material. The research shows that CMC is an effective filler to improve the properties of starch/plant fiber foaming tableware materials, which can greatly promote the development of bio-based polymer foam materials.

The Effect of Carboxymethyl Cellulose (CMC) Addition on The Quality of Biodegradable Plastic from Corn Cob

This study aims to determine the effect of CMC addition on thickness, tensile strength, elongation and biodegradation of biodegradable plastic from corn cob starch. In this study, the addition of Carboxymethyl Cellulose which plays a role in increasing the tensile strength of biodegradable plastics. This research was conducted in 2 stages. The first stage is varying CMC as much as 20%, 30%, 40%, 50% and 60% (w/b starch) and the second stage is mixing corn cob starch as much as 2 grams with CMC 20% - 60% w/b starch. The test results showed that the addition of CMC concentration of 20% w/w with corn cob starch mixing material had an effect on increasing the tensile strength value and decreasing the elongation value of the plastic. The addition of CMC concentration as much as 20%-60% w/b starch with corn cob starch blending material has an effect on increasing the percent weight loss of biodegradable plastics

Extraction and Characterization of Cellulose from Broccoli Stems as a New Biopolymer Source for Producing Carboxymethyl Cellulose Films.

The use of food and agricultural waste-derived carboxymethyl cellulose (CMC) has become of interest due to their biodegradability and cost-effectiveness. In the current research, cellulose was extracted from broccoli stems to produce carboxymethyl cellulose using a carboxymethylation reaction via chloroacetic acid (CAA) and sodium hydroxide (5-10 M). The effects of different synthesis conditions on the degree of substitution (DS) and viscosity of the synthesized CMC powder were investigated. The mechanical properties, water vapor permeability (WVP), and colour of CMC films were also evaluated. The results showed that CMC with the highest DS value (0.60) and the highest viscosity of 0.5 Pa·s could be synthesized from broccoli stems at a concentration of 7.5 M NaOH and a cellulose-to-chloroacetic acid ratio of 1 : 1.2. At CMC concentration of 4 g/100 mL with 0.8 g/100 mL of glycerol, the films had the highest tensile strength (31.91 MPa), whereas with 1.2 g/100 mL glycerol, more flexible films with elongation at break of 27.56% were produced. CMC films with the highest WVP (7.87 × 103 gm2·mmHg-1/day) were made with 6 g/100 mL of CMC and 1.8 g/100 mL of glycerol. This research proposes a new source of cellulose to produce biodegradable packaging materials to initiate a practical basis for food waste reuse.

The effect of different concentrations of carboxy methyl cellulose addition on chemical and organoleptic characteristics of red guava (Psidium guajava) jam sheet

The purpose of this study was to determine the effect of different carboxy methyl cellulose (CMC) concentrations on the chemical and sensory characteristics of jam sheet products (pH value, moisture content, water activity, total dissolved solids and preference test), and to determine the best CMC concentration as food additives for jam sheet products. This study used a completely randomized design (CRD) with five treatments and 4 replications. The treatment applied was the addition of different concentrations of CMC i.e., P0: CMC 0%, P1: CMC 0.25%, P2: CMC 0.5%, P3: CMC 0.75%, and P4: CMC 1.0%. The results showed that there was a significant effect of increasing the concentration of CMC on the pH value, water content, water activity, total dissolved solids and the red guava jam preference test.

Preparation and Mass Loss Study of Sodium Carboxymethyl Cellulose Carbon Aerogel Prepared from Non-Hazardous Material

Carboxymethyl cellulose (CMC) is a derivative of cellulose that shares its biodegradability, biocompatibility, and renewability while being soluble in water and some organic solvents. It is due to these characteristics that the aerogel produced from CMC will share these advantages. In this study, we produced CMC carbon aerogel from different concentrations of CMC aerogels (1%, 2%, 3%, 4%) and under different carbonisation temperatures (300 °C, 400 °C, 500 °C, 600 °C, 700 °C and 800 °C) for a period of 1 hour and 2 hours. The prepared CMC carbon aerogel samples were then analysed based on the difference in mass loss, which differed according to the varying experimental parameters. In temperatures varying from 300 °C to 600 °C, there was a decrease in mass loss as the concentration was increased due to the physical properties of the CMC aerogel. At higher temperatures of 700 °C and 800 °C, the mass loss at higher concentrations of CMC increased due to the completed decomposition and carbonisation of CMC aerogel.

The Production of Coating Film with Sweet Potato Starch and Carboxymethylcellulose from Water Hyacinth on Storage Life Extension of Mango (Mangifera indica L.)

The objective of this research was to study the production of coating films with sweet potato starch (SPS) and carboxymethyl cellulose (CMC) from water hyacinth and to study the effect of the coating on the storage life extension of mangoes. The coating film was prepared by dissolving sweet potato starch in water at a concentration of 5 % w/v and adding CMC from water hyacinth at 5 different concentrations: 0, 5, 10, 15, and 20 % based on the weight of the starch. Glycerol was added as a plasticizer at 20 % of the weight of the starch solution. The mixture was then dried at 65 °C for 18 h. The study found that the thickness of the film decreased with higher concentrations of CMC from water hyacinth. The water activity (aw) ranged from 0.35 to 0.42, and the solubility and water vapor permeability of the film decreased with increasing CMC concentration. In the degradation study, it was observed that the films could biodegrade from 42 to 100 % for 8 weeks, with degradation rates decreasing as the amount of CMC from water hyacinth increased. Coating Mango with 10 % w/w CMC helped delay weight loss, skin color changes, and extended the shelf life of mango for up to 18 days at room temperature (28 ± 2 °C, 65 ± 2 % RH), compared to the control group with a shelf life of 12 days. These results indicate that films made from SPS/CMC from water hyacinth, with glycerol as the plasticizer, can effectively be used for preserving fruits and creating biodegradable films. HIGHLIGHTS The coating film of sweet potato starch (SPS) and Carboxymethylcellulose (CMC) from Water Hyacinth was prepared The effect of adding different CMC concentrations in SPS films was investigated This coating film is cost-effective and biodegradable The coating film of SPS and CMC from water hyacinth enhances the shelf-life of perishable fruit GRAPHICAL ABSTRACT

Characterization of Thermostable Cellulase Enzyme Isolated from a Hot Spring Bacterium: Bacillus sp.

Cellulase is a complex of enzymes which consists of β-1,4-endoglucanase, cellobiohydrolase, and β-glucosidase. Cellulase contributes a significant share to the world enzyme market and is used in number of industries viz; paper and pulp, food and beverage, bioethanol, detergent and textile. The harsh industrial conditions such as high temperature, extreme pH levels and high substrate concentration etc. which is used in such industries adversely effect on structure and activity of enzymes. Therefore, huge amount of chemical catalysts which cause chemical wastes are used in industrial settings instead of enzymes. Since the chemical wastes adversely affect the ecosystem, isolation and characterization of thermostable cellulase enzyme-producing bacteria and exploring the industrial perspective of thermostable enzymes is a better approach towards green chemistry. The present study focused on characterization of cellulase enzyme produced by Bacillus sp., which shows optimum activity at 60 C under neutral conditions, isolated from Gomarankadavala hot spring in Sri Lanka. The effect of different Carbon sources: glucose and lactose, Nitrogen sources: peptone, tryptone, yeast extract and urea on enzyme production and different Carboxymethylcellulose (CMC) concentrations; 0.5%, 1.5% and 2%, on enzyme activity were measured using the DNS method. Under the optimum conditions, cellulase enzyme activity on different substrates: corn cob, rice bran and raw leaves were measured. The highest enzyme production was recorded in the culture medium which added tryptone as the nitrogen source and adding carbon sources to the culture medium showed an increase of cellulase enzyme production. The optimum CMC concentration for the enzyme activity was recorded as 1% and from all the optimized parameters, the substrate; raw leaves showed the highest enzyme activity of 11.305 U/ml. Further, a considerable amount of enzyme activity was recorded on corn cobs and rice bran as well. Thus, the thermostable cellulase enzyme produced by bacterium identified as Bacillus cereus isolated from Gomarankadavala hot spring could be successfully used in industrial settings such as kitchen/industrial waste management, bioethanol production, paper and pulp industry and textile industry which use high temperatures and cellulosic substrates as raw materials. 
 Keywords: Thermostable enzymes, Cellulase, Industrial applications, Hot springs

Application of carboxymethylcellulose in combination with essential oils nano-emulsions edible coating for the preservation of kiwifruit

The present research investigates the effectiveness of nano-emulsified coatings (C-1, C-2, and C-3) in preserving the kiwifruit at a temperature of 10 ± 2 °C with 90–95 % relative humidity (RH) for 30 days. The nano-emulsions were prepared from varied carboxymethyl cellulose (CMC) concentrations with different combinations of essential oils such as thyme, clove, and cardamom. Dynamic light scattering investigation with Zeta Sizer revealed that C-1, C-2, and C-3 nano-emulsions have nano sizes of 81.3 ± 2.3, 115.3 ± 4.2, and 63.2 ± 3.2 nm, respectively. The scanning electron microscopy images showed that the nanoemulsion of C-1 had homogenous spherical globules, C-2 had voids, and C-3 showed a non-porous structure with uniform dispersion. The X-ray diffraction analysis indicated that C-1, C-2, and C-3 nano-emulsion exhibited distinct crystallinity and peaks. The nano-emulsion C-1 had reduced crystallinity, while C-2 had lower intensity peaks, and C-3 had increased crystallinity. The results documented that compared to control kiwifruit samples, the samples coated with C-3 nano-emulsion have decreased weight loss, decay incidence, soluble solids, maturity index activity, ethylene production, total bacterial count, and increased titratable acid, and firmness attributes. The results of current research are promising and would be applicable in utilization in industrial applications.

Tribological and rheological performance of friction modifiers with different viscosities

Friction modifier (FM) in the rail/wheel applications is a special lubrication material that could be applied between the top of rail and the tread of wheel. The application of FM brings many benefits to the wheel-rail interface such as reducing noise, alleviating wheel-rail wear and mitigating corrugation. Viscosity is an important parameter to reflect fluid properties of FM materials. In this study, FM samples with different viscosities were prepared by changing the content of sodium carboxymethyl cellulose (CMC). The tribological and rheological performance of these FM samples were explored using the twin-disc testing machine and rotational rheometer. Furthermore, the relationship between the tribological and rheological results were tried to establish. The results showed that the increase in the content of CMC could increase the viscosity of FM and enhance the solid-like characteristic of FM, which could help FM reduce coefficient of adhesion (COA) level and wheel-rail damage. For the FM material developed in this study, the rational applying amount and the range of viscosity were about 15 μL/time and 200 Pa s to 400 Pa s, respectively, considering the factors of wheel-rail adhesion, wear, potential waste and pumping process in the practical application.

Acid-Induced Gelation of Carboxymethylcellulose Solutions.

The present work offers a comprehensive description of the acid-induced gelation of carboxymethylcellulose (CMC), a water-soluble derivative of cellulose broadly used in numerous applications ranging from food packaging to biomedical engineering. Linear viscoelastic properties measured at various pH and CMC contents allow us to build a sol-gel phase diagram and show that CMC gels exhibit broad power-law viscoelastic spectra that can be rescaled onto a master curve following a time-composition superposition principle. These results demonstrate the microstructural self-similarity of CMC gels and inspire a mean-field model based on hydrophobic interchain association that accounts for the sol-gel boundary over the entire range of CMC content under study. Neutron scattering experiments further confirm this picture and suggest that CMC gels comprise a fibrous network cross-linked by aggregates. Finally, low-field NMR measurements offer an original signature of acid-induced gelation from a solvent perspective. Altogether, these results open avenues for the precise manipulation and control of CMC-based hydrogels.

An Application of Polymer Nanocomposites Based On Carboxymethylcellulose along with Aluminium (Al) and Copper (Cu) Nanoparticles for Increasing Oil Production

As an agent for displacing residual and hard-to-recover oil reserves, polymer nanocomposites based on sodium salts of carboxymethylcellulose (CMC) and aluminium (Al) and copper (Cu) nanoparticles were investigated. It has been shown that polymer nanocomposites are more effective as oil displacement agents than the sodium salt of carboxymethylcellulose itself. Increasing the viscosity of an oil displacement solution can be achieved by varying the concentrations of CMC and nanoparticles. This study thoroughly examined the dynamic viscosities of carboxymethylcellulose (CMC) and polymer nanocomposites that contain CMC and metal nanoparticles (Al and Cu) across various concentrations. The results obtained are robust and reliable. It has been shown that, among polymer nanocomposites containing Al nanoparticles, there is a higher dynamic viscosity compared to its Cu nanoparticle counterpart at equivalent concentrations. This work proposes a simulation reservoir model to enhance oil recovery from hard-to-recovery reserves. Through this reservoir model simulation, the oil recovery factor was calculated using filler sand and oil extracted from a hydrocarbon field. The experimental data revealed the most effective concentration of CMC and nanoparticles for oil displacement. The results suggest that polymer nano composites composed of different metal nano powders have varying impacts on oil displacement efficiency. In this experiment, a composition consisting of Al nanoparticles with a size range of 50-70 manometers (nm) proved to be more successful as an oil displacement agent than a polymer nanocomposite made of Cu nanoparticles and CMC. At these concentrations and combinations, the highest oil recovery factors were achieved.

Examining the Mediating Effects of Attitude and Intention on the Influence of Spatial Knowledge and Regulation Consciousness on Proper Land Use Behavior

This research aims to determine the effect of adding Carboxy Methyl Cellulose (CMC) and watermelon albedo juice. on antioxidant activity, physical properties and organoleptic properties of watermelon albedo yogurt. This study uses Completely Randomized Design (CRD) with the first factor was CMC concentration (0%, 0.2%) and the second factors was Watermelon albedo juice concentration (0%; 20% and 30%). with trplicate. Parameters to be observed include antioxidant activity, pH, viscosity, syneresis and sensory test (aroma, taste and texture). Observational data were tested by ANOVA at a 5% and continued using the Honestly Significant Difference (HSD) at a significant level of 5 %. The best yogurt was the addition of 0.2% CMC and 30% watermelon albedo juice concentration which produces of antioxidant activity 29.67%, pH value 4, 21, syneresis 12.37% and viscosity 3759.33 cP. The sensory resulted in a slightly sweet taste and strong watermelon aroma preffered by the panelists.

Solution plasma mediated synthesis of antibacterial nanobiocomposites using carboxymethyl cellulose and silver as electrodes

In this study, carboxymethyl cellulose (CMC)/Silver nanoparticles (AgNPs) biocomposites were synthesized using a solution plasma process (SPP). The utilization of AgNO3 as a precursor, along with tungsten electrodes, introduces significant impurities into the biocomposites. Therefore, to ensure purity, we employed silver electrodes in the production of biocomposites. The SPP involved discharging plasma at 800 V, 30 kHz for 7 min in CMC solutions with concentrations of 0.3, 0.5, and 1.0%. The UV–Vis spectroscopy results revealed a peak near 400 nm, and the intensity of the peak increased as the CMC concentration decreased. The biocomposites had no change in the chemical structure during SPP. Porous matrix with fringed edges and spherical AgNP was observed by SEM/EDS and TEM analysis. The average particle size and the zeta potential of CMC/AgNPs determined by DLS analysis were 3.1 ± 0.1 nm and −41.8 ± 0.9 mV, respectively. The CMC/AgNP (0.3%, 7 min) exhibited growth inhibition zones ranging from 9.8 to 17.2 mm. The minimal inhibitory concentrations for Gram-positive bacteria, Gram-positive bacteria, and yeast were found to be in the ranges of 33.9–50.9, 102 and 338 μg mL−1, respectively. These results demonstrate that biocomposites of CMC/AgNPs, synthesized using silver electrodes within a CMC matrix, exhibit efficient antimicrobial properties, indicating their potential for sustainable utilization as polymer-based materials for wound healing.

An experimental investigation on the settling of disk particles in annular region: Wall effect and drag coefficient

Settling non-spherical and spherical particles in the annular region is common in many industrial applications. This work shows the intensification of the performance of settling particles in an annular channel by reducing the drag coefficient. The disk/cylinder particles settle in annular channels filled with Newtonian and non-Newtonian fluids. An aqueous solution of different concentrations of glycerin and Carboxymethylcellulose (CMC) was considered as the Newtonian and non-Newtonian fluids. The experimental results reported in the present work covered the 0.17 ≤ blockage ratio ≤0.55, 0.14 ≤ k (flow consistency index) ≤1.81 (Pa.sn), 0.64 ≤ n (flow behavior index) ≤1, and annular channel Reynolds number 0.40 ≤ Re ≤63.44 and 0.05 ≤ Re ≤43.02 in Newtonian and non-Newtonian fluids respectively. The wall factor, f, was increased with the increase in Re and the decrease in blockage ratio. At higher Reynolds numbers (Re), the particle’s wall factor was only influenced by the blockage ratio. The wall factor was reduced due to the particle’s shape change from cylinder to disk, i.e., decreasing the particle’s sphericity. The wall factor of particles is observed to be higher in non-Newtonian than in Newtonian fluids. The critical Reynolds number (Rec ) decreased with the H/d (Height/diameter of disk) ratio and sphericity of the studied particles. Both the drag coefficients, in the absence ( C D ∞ ) and presence ( C D ) of the wall effect, declined with the Reynolds number. Suitable correlations were developed for CD with low values of RMSLD (root mean square logarithmic deviation). The experimentally obtained drag coefficient data were also analyzed successfully using the laminar model available in Ansys (Fluent) −18.1. The computed velocity contours analyzed the wall effect and CD variations successfully. The use of the annular channel as a drag reduction device is encouraged due to the observed higher wall factor and decreased drag coefficient for particle settling in comparison to the non-annular channel.

Quantitative evaluation of adsorption behavior of carboxymethylcellulose on carbon nanotubes by time-domain NMR with the aim of obtaining stable dispersions

This study applied time domain NMR (TD‐NMR) to investigate the effect of carboxymethylcellulose (CMC) adsorption on the dispersion of carbon nanotubes (CNTs) in water. In many aqueous dispersions, the relaxation time measured by TD‐NMR is dominated by bound water on the particle surface. In contrast, since CMC molecules are adsorbed on the hydrophobic surface of CNTs, we proposed a model where relaxation times of hydration water of CMC adsorbed on CNTs, hydration water of free CMC, and bulk water are dynamically averaged in the TD‐NMR measurement. In this study, conversely, we presented the procedure to calculate the fraction of CMC adsorbed on CNTs from the measured relaxation time. Since the adsorbed layer of CMC can stabilize CNTs, the amount of adsorbed CMC is expected to be closely related to the dispersion state of CNTs. TD‐NMR measurements of CNT slurrys with different CMC concentrations showed that the adsorption ratio reached almost 100% (adsorption saturation) when the CMC concentration became larger than that of CNTs. At the adsorption saturation, it was confirmed that the CNT slurry exhibited the lowest apparent viscosity, and the model electrode showed the highest electro-conductivity. In addition, we demonstrated that the adsorption ratio is helpful to assess the dispersion state of CNTs and to optimize the dispersion process. The current study showed that TD‐NMR is very useful for quantitative evaluation of sterically stabilized dispersions because it can evaluate the adsorption rate of adsorbed polymers without dilution.

The Effect of Skim Milk and Carboxy Methyl Cellulose Concentrations on the Characteristics of Tamarillo Velva (Cyphomandra betacea)

This research aims to determine the effect of skim milk and Carboxy Methyl Cellulose (CMC) concentrations and determine the best formulation for making tamarillo Velva. The research used a Completely Randomized Design (CRD) with 2 factors and 2 replications. Data analysis using ANOVA was continued with the Duncan multiple range test (DMRT) at a confidence level of 5%. The 1st factor is the concentration of skim milk (5% (S1), 7.5% (S2), 10% (S3)). The 2nd factor is the CMC concentration (0.25% (C1), 0.50% (C2), and 0.75% (C3)). The parameters observed include analysis of total dissolved solids, vitamin C content, protein content, antioxidant analysis, overrun, melting time, viscosity, and organoleptic analysis, including texture, taste, aroma, and color. The results of the treatment with the concentration of skim milk and CMC had a significant effect on viscosity, overrun, melting time, vitamin C content, total dissolved solids, texture, and color. The best treatment in this study was velva with a concentration of skim milk (10%) and CMC (0.25%) with an antioxidant activity value of 28.20%, vitamin C 16.56 mg/100g, protein 1.60 g, total dietary fiber 14.05%, total dissolved solids 26.9°brix, overrun 15.78%, viscosity 2079 m.Pas, melting time 20.83 minutes, texture scoring test 3.32 (quite soft), and average preference for taste 3.64 (somewhat like), color 3 (somewhat like), aroma 3.6 (somewhat like).

Sodium carboxymethyl cellulose as a stabilizer for fabricating mineralized collagen films with improved wet mechanical properties

Collagen casings, as a type of collagen film, have weak mechanical properties when wet. Therefore, in this research, sodium carboxymethyl cellulose was used to make sodium carboxymethyl cellulose (CMC)-amorphous calcium phosphate (ACP) composite (CMC-ACP) to enhance the collagen film wet mechanical properties. Collagen films were immersed in different CMC-ACP suspensions containing different CMC ratios for 30 min. The wet mechanical properties of collagen films were tested after soaking in deionized water for 2 min. The optimal CMC concentration was determined to be 0.2%, with the Young's modulus (YM) of the collagen film increasing from 0.043 MPa to 0.054 MPa, elongation at break (EAB) increasing from 41.42% to 56.98%, tensile strength (TS) increasing from 1.51 MPa to 2.5 MPa, and toughness (TH) increasing from 316 kJ/m3 to 797.63 kJ/m3. The effects of CMC concentration on the effectiveness of CMC-ACP and the mechanism of action on collagen films were studied by using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). In conclusion, CMC-ACP can mineralize collagen films and improve their wet mechanical properties when using appropriate concentrations.

Formulations and assessments of structure, physical properties, and sensory attributes of soy yogurts: Effect of carboxymethyl cellulose content and degree of substitution

Soy yogurts present challenges, including absence of tender and slipperiness mouthfeel, and poor stability. This study aimed to investigate the impacts of carboxymethyl cellulose (CMC) with degrees of substitution of 0.7 (CMC0.7) and 1.2 (CMC1.2) at concentrations ranging from 0 % to 1.1 % on the stability, microstructure, rheology, tribology, and mouthfeel of soy yogurts. As the CMC concentration increased from 0 % to 0.3 %, soy yogurts displayed a coarser microstructure, decreased stability, and increased gel strength. As the concentration of CMC further increased from 0.5 % to 1.1 %, soy yogurts exhibited trends of a smoother microstructure, increased stability, and softer gel strength. Notably, soy yogurts with CMC0.7 demonstrated a superior water holding capacity (WHC) than soy yogurts with CMC1.2. Tribological measurements indicated that soy yogurts with CMC0.7 at a 0.7 % concentration had the lowest coefficient of friction (COF) value among most sliding speeds, showing a 23 % reduction compared to soy yogurts without CMC at a sliding speed of 10 mm/s. Moreover, sensory evaluation showed that soy yogurts with CMC0.7 at a 0.7 % concentration had the highest total score in mouthfeel evaluation. Therefore, the addition of CMC0.7 within the concentration range of 0.5 % to 1.1 % may produce stable and delicate yogurts.

Poly(vinyl alcohol)/Carboxymethyl Cellulose/Cellulose nanofibrils nanocomposite as coating for food packaging paper

ABSTRACT Cellulose nanofibrils (CNF) can be modified to be used as a coating on food paper packaging. Previous research on PVA/CNF composites showed a low viscosity, which impacted their performance on the coating paper process. To overcome this problem, a thickening agent, such as carboxymethyl cellulose (CMC), is needed. In this work, the effect of CMC on PVA/CMC/CNF nanocomposites was investigated by varying the concentrations of CMC with PVA/CMC and CNF ratio of 80:20 and 90:10. The nanocomposites were characterized by their physical and tensile properties which could affect their coating performance. Moreover, the coating process was conducted on paper and the performances of the coated paper were studied. The results showed that the increase in CMC concentration led to an increasing viscosity and good zeta potential, suggesting good dispersion. Moreover, the addition of CMC improved the tensile properties of PVA/CMC/CNF nanocomposites. However, SEM analysis of PVA/CMC-1:CNF (80:20) revealed the occurrence of agglomeration which might influence the performance of the coated paper. Interestingly, PVA/CMC-1:CNF (80:20) had an excellent water resistance, with the lowest Cobb60. Moreover, the addition of CMC 1 wt% increased WVTR, which remained lower than the blank sample. Meanwhile, PVA/CMC-2:CNF (80:20) demonstrated the best performance in the oil absorption and tearing resistance test. In summary, the addition of CMC can effectively improve the physical and tensile properties of the PVA/CMC/CNF, as well as the barrier properties and tear strength of the PVA/CMC/CNF coated paper. The results demonstrate the potency of this material as a coating for food packaging paper.