Karaya Gum Research Articles

Pickering emulsions stabilized by ternary complexes involving curcumin-modified zein and polysaccharides with different charge amounts for encapsulating β-carotene

In this research, zein was modified with curcumin to obtain covalent and non-covalent complexes. They were further covered with polysaccharides (gum arabic or gum karaya) possessing different surface charge amounts to obtain ternary nanoparticles for preparing novel antioxidant Pickering emulsions. The addition of curcumin to the zein-polysaccharide system significantly retarded the UV degradation of the encapsulated β-carotene (maximum retention ∼ 97%) and effectively inhibited the lipid oxidation of the emulsions. In vitro gastrointestinal digestion assays showed that gum karaya significantly delayed the release of free fatty acids, thereby improving the bioaccessibility of β-carotene (the highest bioavailability ∼ 38%). By comparing the performance of the complex particles, the weakly charged polysaccharides were superior to the highly charged ones, while zein-curcumin covalent binding was superior to non-covalent binding in the above experiments. This study provides innovative perspectives on the use of novel Pickering emulsions to provide ideal protection and bioavailability of lipophilic nutraceuticals.

Karaya/Gellan-Gum-Based Bilayer Films Containing 3,3'-Diindolylmethane-Loaded Nanocapsules: A Promising Alternative to Melanoma Topical Treatment.

This study aimed to incorporate nanocapsules containing 3,3'-diindolylmethane (DIM) with antitumor activity into a bilayer film of karaya and gellan gums for use in topical melanoma therapy. Nanocarriers and films were prepared by interfacial deposition of the preformed polymer and solvent casting methods, respectively. Incorporating DIM into nanocapsules increased its antitumor potential against human melanoma cells (A-375) (IC50 > 24.00 µg/mL free DIM × 2.89 µg/mL nanocapsules). The films were transparent, hydrophilic (θ < 90°), had homogeneous thickness and weight, and had a DIM content of 106 µg/cm2. Radical ABTS+ scavenger assay showed that the DIM films presented promising antioxidant action. Remarkably, the films showed selective bioadhesive potential on the karaya gum side. Considering the mechanical analyses, the nanotechnology-based films presented appropriate behavior for cutaneous application and controlled DIM release profile, which could increase the residence time on the application site. Furthermore, the nanofilms were found to increase the permeation of DIM into the epidermis, where melanoma develops. Lastly, the films were non-hemolytic (hemolysis test) and non-irritant (HET-CAM assay). In summary, the combination of karaya and gellan gum in bilayer films that contain nanoencapsulated DIM has demonstrated potential in the topical treatment of melanoma and could serve as a viable option for administering DIM for cutaneous melanoma therapy.

Cooking, sensory and in-vitro digestibility characteristics of rice as affected by rice-water ratio and karaya gum concentration

Cooked rice has high starch digestibility. Prolonged and excess consumption of polished rice has been associated with the incidence of diabetes amongst rice eating populations. Therefore, researchers are working on extensively to devise strategies that could retard digestion of cooked rice. Keeping this fact into consideration, four rice cultivars (SR-4, K-39, Mushq Budij and Zhag) grown in Kashmir were milled and cooked with varying concentrations (0, 2.5 and 5.0% w/w, rice basis) of karaya gum at different rice-water ratios (1:10 and 1:1.8). The prepared rice samples were evaluated for cooking and sensory properties, in-vitro digestibility and structural characteristics. Cooking of rice with karaya gum (2.5–5.0%) at large rice-water ratio (1:10) increased minimum cooking time (19.0–25.0 min) and water uptake ratio (3.23–4.69) of samples. Also, rice cooked in excess water had better sensory acceptability scores than those cooked in less water. At large rice-water ratio, Zhag rice prepared with karaya gum (2.5%) had acceptable hardness and flavour scores. With increase in gum concentration, the equilibrium starch hydrolysis percentage (C∞) and estimated glycemic index (eGI) scores of cooked rice decreased, irrespective of cultivars and rice-water ratio. Maximum reduction in C∞ was observed for Mushq Budij rice (85.20%) prepared with karaya gum (5.0%) at large rice-water ratio (1:10). Fourier transform infrared spectra of gum cooked rice samples revealed shifting of peak at 3250.0 cm−1 to higher intensities indicating hydrogen bonding interaction of starch and gum. From X-ray diffraction studies, the highest relative crystallinity (16.20%) was observed for rice prepared with 5.0% gum concentration. Therefore, cooking of rice with karaya gum at large rice–water ratio can be considered to slow down starch hydrolysis process of cooked rice.

Evaluation of covalent and supra-molecular interactions in phosphated galacturonic-glucuronic acid for network structure for use in wound dressings

Keeping in view the wound healing properties of sterculia gum (SG) and ceftriaxone in consideration, in the present work, antibiotic drug encapsulated SG and poly(vinylphosphonic acid) [poly(VPA)] based copolymeric hydrogel wound dressings were designed to enhance the wound healing. Copolymers were characterized by FESEM & EDS, AFM, FTIR, 13C NMR, XRD, TGA and biomedical assay of blood compatibility, mucoadhesion and antioxidant properties. AFM analysis revealed 76.5 nm average roughness and XRD analysis showed sharp peaks at 2θ = 21°. FTIR spectrum of copolymer indicated characteristic peaks at 1116 cm−1 due to stretching vibration of P = O groups of poly(VPA) and twin peaks at 985 and 920 cm−1 due to asymmetric and symmetric vibration of P-O respectively and depicted grafting of phosphated polymers onto gum. The hemolysis test (hemolysis index = 3.40 ± 0.18%) revealed biocompatible nature and the adhesion test demonstrated 84 ± 5.00 mN detachment force which was required to detach the copolymer from the mucosal membrane. Hydrogel dressings absorbed 6.0 ± 5.00 (g/g gel) simulated wound fluid to main the moist wound environment. They were found permeable to O2 and impermeable to microbes and also exhibited antioxidant character. The release profile of ceftriaxone elucidated sustained release of encapsulated ceftriaxone drug with non-Fickian diffusion mechanism and was best fitted in first order kinetic model. Covalent and supra-molecular interactions formed in phosphated galacturonic-glucuronic acid of sterculia gum (SG) were found useful for sustained drug delivery and mucoadhesive properties. These biophysical interactions demonstrated the suitability of antibiotic-encapsulated network structures for wound dressing applications.

Optimization of Colour Parameters of Different Gluten-free Pasta Samples Using Response Surface Methodology

Colour plays an important role in consumer’s perception and acceptability of the food product. Therefore, colour measurement and analysis is one of the most important quality attributes to optimize the quality and value of food. Different blends of gluten-free maize flour, finger millet (Ragi) flour and quinova flour were used as raw materials for the development of pasta. Hunter Lab Colorimeter was used for measuring the surface color of the uncooked pasta samples. High quality pasta (either fresh or dried) is normally yellow in colour and the degree of yellowness can be calculated by using b* and L* values. Quality of pasta developed by different blend ratio of maize, ragi and quinova flours with different levels of CMC, Karaya Gum and dried at different drying temperature and air flow rates were evaluated in terms of L* values (lightness), b* values (yellowness) and Yellowness Index (YI). Results of colour analysis of gluten-free pasta samples indicated a significant effect of flours on L*, b* and YI while drying air temperature have a significant effect on b* values. Pasta samples prepared following optimized formulation 50:25:25 (Maize flour: Ragi, flour: Quinova flour) blend ratio, 5g CMC per 100g of blend ratio, 2.5g Karaya Gum per 100g of blend ratio, 60 0C drying air temperature and 0.78 m/sec. air flow rate provided optimum L*, b* and YI values with overall desirability of 0.545.

Formulation Development and Characterization of Vancomycin Hydrochloride Colon-Targeted Tablets Using In-Situ Polyelectrolyte Complexation Technique

Introduction: Vancomycin hydrochloride (VH) is an amphoteric glycopeptide antibiotic used to manage enterocolitis and pseudomembranous colitis. However, VH is prone to proteolytic degradation in the stomach, thus obscuring the drug entry into the colon. Colon-targeted drug delivery can prevent gastric degradation and localise the drug in the colon. &#x0D; Methodology: The applicability of in situ polyelectrolyte complexation technique using the polymers Chitosan, Karaya gum, and Hupu gum at various concentrations along with enteric coating using Eudragit S100 was studied for the preparation of colon-targeted tablets of VH.&#x0D; Colon-targeted tablets of VH are developed by incorporating natural polymers like chitosan, karaya gum, and hupu gum at different concentrations such that in-situ polyelectrolyte complex is formed and the formulations were then coated with Eudragit S100(6%, 8%, and 10% weight gain) to release the drug in a controlled manner in the colon. &#x0D; Results: Prepared formulations were subjected to in vitro, ex vivo, and in vivo evaluation studies. Out of all the prepared formulations, the formulation H2C10 prepared with 10:2 PEC and 10% Eudragit S100 coating has shown a sufficient lag time of 2 hours in 0.1N HCl, 3 hours of lag time in pH 6.8 phosphate buffer and has shown a 100.02% drug release at 22 hours in pH 7.4 phosphate buffer. &#x0D; Conclusion: The research results suggested that a colon-targeted drug delivery system of VH can decrease drug degradation and achieve higher concentrations in the colon to provide more therapeutic benefits.

Designing biphasic gels from dietary fiber sterculia gum by green approach using high energy radiation for biomedical applications

Polysaccharides have been applied in food and biomedical applications. Bioactive dietary fiber sterculia gum (SG) has been used for treatment of diarrhea. Therefore, in present research, SG has been used for development of drug delivery (DD) system for controlled release of metronidazole to improve its pharmacotherapy for amoebic dysentery. Co-polymers were characterized by Cryo-scanning electron microscopy (Cryo-SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, 13C nuclear magnetic resonance (NMR) spectroscopy,), X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Haemolytic index values of grafted product was less than 5 percent and DPPH assay illustrated free radical scavenging of hydrogels and bigels 74.00 ± 0.003% and 47.00 ± 0.005% respectively. Mucoadhesion experiment demonstrated that both hydrogels and bigels exhibited adhesion with intestinal mucus membrane required 0.034 ± 0.004 and 0.037 ± 0.002 N detachment force during mucoadhesion test. Diffusion of metronidazole was slow in sustained manner with Fickian diffusion mechanism. Overall results revealed biocompatible, antioxidant, and mucoadhesive properties of sterculia gum based gels which may be useful for DD applications of gastrointestinal infections.

NICORANDIL MUCOADHESIVE MICROSPHERES: FORMULATION DEVELOPMENT, PHYSICO-CHEMICAL AND FUNCTIONAL CHARACTERIZATION

Objective: The study aims to prepare and evaluate Nicorandil mucoadhesive microspheres to improve the oral physicochemical properties of nicorandil and mucoadhesion to extend the residence time at the absorption site. Methods: Nicorandil mucoadhesive microsphere was prepared by emulsion cross-linking method using fenugreek gum, karaya gum as polymer, and glutaraldehyde as a cross-linking agent. Drug entrapment efficiency, particle size, % swelling index, mucoadhesion study, differential scanning calorimetry, powder x-ray diffraction, Fourier transform infrared spectroscopy, and in vitro dissolution studies were used to characterize the microspheres. Results: The characterization studies indicated the formation of mucoadhesive microspheres. The nicorandil mucoadhesive microspheres particle size is130.83±0.48, entrapment efficiency 66.91±0.54, swelling index 82.69±0.40, % mucoadhesion 95.22±0.13 and in vitro drug release was found to be 89.96±0.17 % at the end of 12 h. Conclusion: This research work successfully formed nicorandil mucoadhesive microspheres formulation using the emulsion cross-linking method. Encapsulation efficiency and other physicochemical and functional characterization of microspheres suggested the successful formation of nicorandil mucoadhesive microspheres.

Effect of Gum Karaya on release pattern of Amoxycillin trihydrate from Encapsulated Matrix-based Formulations

Hydrophilic swellable polymers can be well used for the fabrication of matrix formulations. The present investigation aimed to develop controlled release matrix formulations of Amoxicillin trihydrate with different concentration of gum karaya, without changing the other factors. The matrix granules, prepared by wet granulation process were first evaluated for different micrometrics properties like bulk density, tapped density, Hausner’s ratio, Carr’s index. The drug content and swelling behavior were also investigated in granular form. After that the matrix granules were encapsulated in empty gelatin shell. The encapsulated granules of Amoxycillin trihydrate were subjected to dissolution studies. The drug release data were analyzed to interpret the drug release kinetics. The drug release data was fitted in kinetic models of zero order, first order, Higuchi and Korsmeyer-Peppas equation. For the formulations with higher concentration of gum karaya, the cumulative percent of drug released versus time plot exhibits curvilinear nature, which suggests that drug release is not dominated by zero order kinetics. The results showed that drug release is much more acquainted with Korsmeyer–Peppas and Higuchi models. The granules with 10-15% of gum karaya reveal the dominance of the highly swollen layer which controls the drug release from the matrix granules.

Development and Evaluation of Floating Bilayer Tablet Containing Combination of Oxethazine and Cefixime Trihydrate

Aim The objective of present work was to formulate and evaluate bilayer tablets of Oxethazine and Cefixime trihydrate developed by direct compression method for effectively treating gastric ulcer and H. pylori infection.Methods The tablets were prepared having immediate release layer of Oxethazine and sustained release layer of Cefixime trihydrate. Sodium starch glycolate was used as super disintegrant for immediate release layer. The bilayer tablets were prepared by direct compression method using HPMC K100 and natural polymers like xanthan gum guar gum karaya gum which release the drug for 12 hours. Pre-compression parameters post-compression parameters and physical characteristics were evaluated for prepared formulations.Results The release of the Oxethazine from the immediate release layer was found to be 94.6plusmn0.02 in 30 minutes. The release of Cefixime trihydrate for the sustained release floating layer was found to be 99.88plusmn0.06 in 12 hours. The data obtained from in vitro release were fitted into the various kinetic models Zero Order Higuchi First Order and Kors MeyerndashPepparsquos Model.Conclusion The bilayer tablets developed offer both immediate release of Oxethazine and sustained release of Cefixime trihydrate. This suggests their potential as a viable option for treating gastric ulcers and H. pylori infections using an innovative dosage form.

Formulation and In-Vitro Evaluation of Sustained Release Pilocarpine Ocuserts Using Modified Karaya Gum Extracted from Sterculia urens

Ocular inserts of Pilocarpine nitrate (PN) were prepared using modified karaya gum (MKG) alone as release retarding polymer and in combination with the copolymer sodium alginate. Modification of the karaya gum was done by treating it with the trisodium trimetaphosphate (STMP) by cross linking method and evaluated for its physicochemical properties. Films of the MKG were prepared by employing solvent casting method using varying concentrations (600mg, 500mg and 400mg) of MKG and the sandwiching technique was used for the loading of drug. Sodium alginate (SA) and PN blend were prepared by triturating their appropriate amounts. Six ocusert formulations (F1-F6) were prepared with different concentrations of the polymer i.e MKG and SA while the amount of PN was kept constant in formulations. Formulations F1-F3 contained the MKG alone in varying concentrations (600mg, 500mg and 400mg) and F4-F6 contained SA (0.5 mg) in addition to MKG. The surface pH of prepared ocuserts from the formulations (F1-F6) was in the range of 6.63 to 6.8. Thickness range of the ocuserts was from 0.21 to 0.32 mm. Dissolution profiles of prepared ocuserts were studied and drug release was found within the range of 69.2± 1.36 % (F4, minimum) to 90.5± 3.21% (F3, maximum). Overall results of the study concluded that ocuserts fabricated with MKG and SA at optimized concentrations have the potential to sustain the release of PN and therefore reducing dosing frequency and adverse effects.

Synthesis and Characterization of Sterculia Gum Polysaccharide-Poly(bis[2-methacryloyloxy]ethyl Phosphate Copolymeric Network Hydrogels for Use in Drug Delivery

Synthesis and Characterization of Sterculia Gum Polysaccharide-Poly(bis[2-methacryloyloxy]ethyl Phosphate Copolymeric Network Hydrogels for Use in Drug Delivery

Impregnating graphene oxide into polyvinylsulphonic acid–sterculia gum hydrogels to modulate antibiotic drug vancomycin interactions for controlled drug delivery applications

Recently, graphene oxide (GO) has been well explored for biomedical applications due to its stability, biocompatibility and large surface area. Herein this research, GO incorporated sterculia gum-poly(VSA) hydrogels were designed by encapsulating vancomycin antibiotic drug for use in colon specific drug delivery.

Recent Advances in the Multifunctional Natural Gum-Based Binders for High-Performance Rechargeable Batteries

Natural gum derived from the natural surrounding (gum arabic, guar gum, xanthan gum, gellan gum, fenugreek gum, karaya gum, and acacia gum) is one of the most abundant polysaccharides currently present around the world. As natural gum dissolved solution can be very sticky in nature, its role as a binder for both anodes and cathodes in rechargeable batteries have been recently significantly researched. Although much research has been delved into using natural gum as a feasible binder for rechargeable batteries, little investigation so far has taken place to compile, summarize, analyze, and evaluate the current status-quo of the natural gum-based binder research, as well as understanding some of the obstacles and issues that may need to be addressed. This review gives a comprehensive review on the natural gum-based binder that was used for both anode and cathode in rechargeable batteries and how each kind of natural gum improved the electrochemical performance in terms of cycle retention and rate capabilities. Furthermore, more systematic analysis and future projections for the research on natural gum-based binders are presented, which will serve to further the promising research related to utilizing natural gum as an efficient binder for rechargeable battery systems.

Polymer and biopolymer organic-inorganic composites containing mixed oxides for application in energy up- and down-conversion

Organic-inorganic composites are interesting for many commercial applications— the chemical and thermal stability of inorganic oxides combined with the processability and flexibility of organic compounds and polymers provides these composites with attractive mechanical, optical, and thermal properties. In general, the desired properties cannot be found in one single constituent, but adequate association of the components affords composites with complementary properties. In this study, we have synthesized and characterized organic-inorganic composites based on the natural polymers Gellan Gum and Karaya Gum containing luminophores consisting of niobium and gadolinium mixed oxides doped with Eu3+ or Yb3+/Er3+. In this paper luminophores were prepared by a modified non-hydrolytic sol-gel route, and was obtained the organic-inorganic composites by the casting technique. The investigated how the luminophore concentration, 1.0 or 3.0% m/m of gum, affected the luminescent properties of the composites. For all the composites doped with Eu3+, the down-shifting luminescence results revealed an intense emission band at 612 nm, due to the 5D0 → 7F2 transition of Eu3+, as well as an emission band between 300 and 500 nm, attributed to polymer emission, which shifted the chromaticity coordinates toward the blue region. As for the composites doped with Yb3+/Er3+, they displayed bands at 1005 and 1535 nm, ascribed to the 2F5/2 → 2F7/2 and 4I13/2 → 4I15/2 transitions of Yb3+ and Er3+, respectively. The up-conversion luminescence results evidenced emission bands in the visible region, at 520, 550, and 655 nm, assigned to the 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 transitions of Er3+, respectively, indicating that two photons were absorbed.

Improved Mucoadhesion, Permeation and In Vitro Anticancer Potential of Synthesized Thiolated Acacia and Karaya Gum Combination: A Systematic Study.

Thiolation of polymers is one of the most appropriate approaches to impart higher mechanical strength and mucoadhesion. Thiol modification of gum karaya and gum acacia was carried out by esterification with 80% thioglycolic acid. FTIR, DSC and XRD confirmed the completion of thiolation reaction. Anticancer potential of developed thiomer was studied on cervical cancer cell lines (HeLa) and more than 60% of human cervical cell lines (HeLa) were inhibited at concentration of 5 µg/100 µL. Immobilized thiol groups were found to be 0.8511 mmol/g as determined by Ellman’s method. Cytotoxicity studies on L929 fibroblast cell lines indicated thiomers were biocompatible. Bilayered tablets were prepared using Ivabradine hydrochloride as the model drug and synthesized thiolated gums as mucoadhesive polymer. Tablets prepared using thiolated polymers in combination showed more swelling, mucoadhesion and residence time as compared to unmodified gums. Thiol modification controlled the release of the drug for 24 h and enhanced permeation of the drug up to 3 fold through porcine buccal mucosa as compared to tablets with unmodified gums. Thiolated polymer showed increased mucoadhesion and permeation, anticancer potential, controlled release and thus can be utilized as a novel excipient in formulation development.

Development of dietary fibers moringa-sterculia gum hydrogel for drug delivery applications

IntroductionKeeping in view the role of polysaccharide gums in pharmaceutical applications. Herein this research, Moringa gum (MOG) and Sterculia gum (SG) polysaccharides have been explored to design the network structure in the form of hydrogels which can act as a wound dressing for better wound healing. Both gums are hydrophilic stem exudate and their anti-fungal and antioxidant activities have been reported for wound healing which can help the increase in wound healing potential of the antibiotic drug encapsulated hydrogel dressings. ObjectivesTo design the moringa gum, sterculia gum and polyacrylic acid based hydrogel wound dressings by graft copolymerization method impregnated with antibiotic drug levofloxacin for better wound care. MethodologyThe co-polymers were prepared by grafting and crosslinking of the polyacrylic acid onto MOG and SG. The copolymers were characterized by cryo-SEM, AFM, FTIR, 13C NMR and swelling studies along with the evaluation of blood compatibility, wound fluid absorption, antioxidant activity, permeability (O2, H2O and, microbial), mucoadhesion, mechanical and in vitro release dynamics of antibiotic drug levofloxacin. Results and conclusionThe Cryo-SEM and AFM images of the hydrogels showed the porous nature and rough surface morphology of the hydrogels. The porosity in the hydrogel controlled the wound fluid absorption and drug diffusion from dressing. The release of the levofloxacin from MOG-cl-SG-co-poly(AAc) hydrogel occurred by the non-Fickian diffusion mechanism and release profile was best fitted in the Korsmeyer-Peppas kinetic model of drug release in the simulated wound fluid . The gum-based dressings were found permeable and antioxidant in nature. Overall, these hydrogels could be proposed as suitable materials for biomedical applications including drug delivery and wound dressing for better wound care.

RESPONSE OF GROWER RABBITS FED DIETS CONTAINING ROASTED KARAYA GUM TREE (Sterculia setigera) SEED MEAL

This study was carried out to determine the response of weaned rabbits to roasted Karaya gum tree seed meal in a twelve weeks experiment. Three diets were formulated with control diet (I) having 0 % Karaya gum tree seed meal (KGSM) while diets II and III had 5 % and 10 % KGSM respectively. Thirty-six heterogenous mixed sexes of weaned rabbits with average initial weight of 525 g were allocated to the three diets in completely randomized design with twelve rabbits per treatment. At the end of the twelve weeks, digestibility trial was conducted. Feed intake and weight gains were determined. Feed intake and weight gains were significantly (P&lt; 0.05) higher in diet containing 5 % KGSM. Feed conversion ratio was lower (P&lt; 0.05) in treatment containing 5 % KGSM than control and 10 % KGSM diets. Nutrient digestibility was significantly (P&lt; 0.05) higher in diet containing 0 % roasted KGSM (control) than treatments with 5 % and 10 % KGSM. However, the values for nutrient digestibility of diet containing 0 % roasted KGSM (control) and treatment with 5 % KGSM were numerically within close range indicating 5 % level of inclusion is comparable to 0 % inclusion. Nutrient digestibility decreased with increase (10 %) in roasted KGSM in the diet. This experiment had revealed that up to 5 % level of inclusion of roasted Karaya gum tree seed meal can be incorporated in the diet of rabbit without negative effects on growth performance and nutrient digestibility.

Impact of weakly charged insoluble karaya gum on zein nanoparticle and mechanism for stabilizing Pickering emulsions

The effect of weakly charged insoluble karaya gum (KG) on zein colloidal nanoparticles (ZKGPs) for stabilizing Pickering emulsions was investigated. Due to weak surface charge, KG could cover the surface of zein particles by hydrogen bonds and weak electrostatic interactions. With the increase in coverage, the zeta potential of ZKGPs changed from positive to negative values close to zero and the average particle size tended to become larger. The closest neutral wettability (89.85°) was achieved when the zein/KG mass ratio was 1:1. The samples prepared with high oil volume fraction (φ = 0.5–0.75) and high particle concentration (1.0–1.3 %, w/v) formed emulsion gels easily and showed higher storage stability. CLSM images also confirmed that ZKGPs could be distributed in the continuous phase to enhance the emulsion network structure. Consequently, weakly charged ZKGPs reduced the emulsification energy barrier and increased the coverage and steric hindrance of particles at the oil/water interface. These findings provide new ideas for the development of stable Pickering emulsions for application in food textural modification as well as encapsulation and delivery of bioactive substances.

Study on equilibrium moisture sorption characteristics and modeling of Karaya (Sterculia urens Roxb.) gum

BackgroundKaraya gum is heavily acetylated polysaccharide and used for medicinal purposes as a bulk-forming laxative. It is also used in the paper and textile industries as well as food stabilizer. So its moisture sorption behavior study is important. The moisture sorption isotherms of karaya gum were investigated at four experimental temperatures (30, 40, 50 and 60 °C) under the water activities range from 0.10 to 0.95 using static gravimetric method.ResultsMaximum value of equilibrium moisture content (EMC) of karaya gum (39.7%, db) was noted with the set of highest water activity (0.92) at lowest temperature (30 °C) and minimum value of EMC (2.5%, db) with lowest water activity (0.11) at highest temperature (60 °C). The sorption data were fitted with GAB, Iglesias and Chirife, Caurie, Halsey and BET models. The adequacy of the sorption isotherm models were observed statistically using goodness of fit parameters. The well-known GAB model best interpreted the equilibrium data in a satisfactory manner in the test gum. The monolayer moisture content, estimated using GAB model, was found to be 12.66 g/100 g and 7.4 g/100 g gum at 30 °C and 60 °C, respectively. The isosteric heat of sorption was found to be maximum (36.24 kJ/mol) at 5% moisture content (db) of karaya gum.ConclusionMoisture sorption behavior of karaya gum was found to be temperature dependent. EMC decreases with the increase in temperature at particular water activity. The sorption behavior of the test gum expressed the typical type-II sigmoid-shaped curve. Isosteric heat of sorption of karaya gum was decreased with the increase in moisture content.