Showing papers on "Guar gum published in 1999"

Studies of guar gum compression-coated 5-aminosalicylic acid tablets for colon-specific drug delivery.

Abstract: The aim of this study was to develop colon-specific delivery systems for 5-aminosalicylic acid (5-ASA) using guar gum as a carrier. Core tablets containing 5-ASA were prepared by wet granulation with starch paste and were compression coated with coating formulations containing different quantities of guar gum (300, 200, 150, and 125 mg). In vitro drug release studies were carried out in simulated gastric and intestinal fluids and in pH 6.8 buffer containing rat cecal contents. The application of 175 mg of coating formulation containing 150 mg of guar gum over 5-ASA core tablets resulted in the release of less than 2% drug in simulated gastric and intestinal fluids and about 93% of 5-ASA in pH 6.8 buffer containing rat cecal contents. Differential scanning calorimetric (DSC) studies showed the absence of any interaction between 5-ASA and the excipients on storage at 45°C for 12 weeks. The study confirmed that selective delivery of 5-ASA to the colon can be achieved using guar gum as a carrier in the form o...

Rheology and Microstructural Changes during Enzymatic Degradation of a Guar−Borax Hydrogel

Abstract: Hydrogels composed of borax cross-linked guar galactomannans are enzymatically degraded using endo-β-mannanase, an enzyme which cleaves the polymer chain backbone. Dynamic rheological measurements show the elastic (G‘) and viscous (G‘ ‘) moduli to be sensitive to gel structure and to reduce significantly during the enzymatic hydrolysis process. The reduction in rheological properties shows three distinct regimes: an initial large decrease, a slower reduction rate at intermediate times, and an accelerated reduction at longer degradation times. In contrast, the polymer chain molecular weight, obtained from gel permeation chromatography, reduces rapidly at short times and at a slower rate subsequently. We therefore find the kinetics of moduli reduction to be dictated by the relationship between gel structure and rheological properties, rather than purely the rates of chain scission. At short times, the large decrease in moduli is analogous to changes in molecular weight and can directly be attributed to cha...

Screening of hydrocolloids for reduction in oil uptake of a model deep fat fried product

Abstract: Reduction of oil content in deep fat fried foods would be welcome by both the food manufacturers and the consumers. Among the many approaches that have been evaluated for this purpose, use of hydrocolloid additives is believed to be most promising. Work in this area is restricted mostly to cellulose derivatives. The mechanism of action of these derivatives is attributed to formation of an oil resistant barrier film, an alteration in surface hydrophobicity of the product being fried, and the thermal gelation. However, most hydrocolloids would alter the surface hydrophobicity, and many of them have the ability to form films. Furthermore, the presence of other food constituents can alter all these properties. Hence, hydrocolloids at 0.25— 2.00 % (on the basis of chickpea flour) were screened for their ability to reduce oil uptake in sev, a model deep fat fried product prepared from chickpea flour. Results obtained indicate that the ability to reduce oil uptake in this product decreases in the following order: gum arabic > carrageenan > gum karaya > guar gum > carboxymethylcellulose > hydroxypropylmethyl cellulose. Hydrocolloids such as xanthan, gum ghatti, gum tragacanth, and locust bean gum were found to be ineffective (<10 % reduction in the oil content) for this purpose. Screening von Hydrokolloiden zur Reduktion der Olaufnahme eines modellhaft frittierten Produkts.Die Reduktion des Olgehalts in frittierten Nahrungsmitteln wurde sowohl von den Nahrungsmittelherstellern als auch den Konsumenten begrust werden. Unter den vielen Ansatzen, die zu diesem Zweck bereits ausgewertet wurden, gilt der Einsatz von hydrokolloiden Zusatzen als am vielversprechendsten. Die Arbeit in diesem Gebiet ist vor allem auf Zellulosederivate beschrankt. Die Aktionsmechanismen dieser Derivate werden der Bildung eines olresistenten Films, der Anderung der Oberflachenhydrophobizitat des frittierten Produkts und der thermischen Gelatinisierung zugeschrieben. Allerdings wurden die meisten Hydrokolloide die Oberflachenhydrophobizitat verandern, und viele von ihnen haben die Fahigkeit, einen Film auszubilden. Daruber hinaus kann das Vorhandensein anderer Nahrungsmittelbestandteile diese Eigenschaften andern. Daher wurden Hydrokolloide in einer Konzentration von 0,25— 2,00 % (auf der Basis von Kichererbsenmehl) im Hinblick auf ihre Fahigkeit, die Olaufnahme in Sev, einem modellhaft frittierten Produkt, zu reduzieren, gescreent. Die gewonnenen Ergebnisse zeigen, das die Fahigkeit, die Olaufnahme bei diesem Produkt zu reduzieren, in der folgenden Reihenfolge abnimmt: Gummi arabicum > Carrageenan > Gummi karya > Guar Gummi > Carboxymethylzellulose > Hydroxypropylmethylzellulose. Hydrokolloide, wie Xanthan, Gummi ghatti, Gummi tragacanth und Johannisbrot-Gummi, stellten sich fur diesen Zweck als nutzlos heraus (<10 % Reduktion des Olgehalts).

Dietary Effect of Guar Gum and its Partially Hydrolyzed Product on the Lipid Metabolism and Immune Function of Sprague-Dawley Rats

Abstract: The dietary effect of the water-soluble dietary fibers (WSDF), guar gum, partially hydrolyzed guar gum (PHGG), glucomannan, highly methoxylated (HM) pectin, on the serum lipid level and immunoglobulin (Ig) production of Sprague-Dawley rats was compared with that of water-insoluble cellulose. Although serum total cholesterol and triglyceride levels were significantly lower in the rats fed with WSDF than in those fed with cellulose, a decrease in the level of phospholipids was only observed in the rats that had been fed on guar gum or glucomannan. In addition, all WSDF feeding enhanced IgA productivity in the spleen and mesenteric lymph node lymphocytes, although the increase in serum IgA level was only observed in the rats fed on WSDF, and not on PHGG. When mesenteric lymph node lymphocytes were cultured in the presence of various concentrations of guar gum or glucomannan, no significant increase in Ig production was apparent. These data suggest that WSDF indirectly enhanced the Ig production of lymphocytes, and that serum lipid reduction and IgA production-enhancing activities of WSDF were dependent on their molecular sizes.

Urea–formaldehyde crosslinked starch and guar gum matrices for encapsulation of natural liquid pesticide [Azadirachta Indica A. Juss. (neem) seed oil]: swelling and release kinetics

Abstract: Polymeric granules were prepared by matrix encapsulation containing 20, 35 and 50% (w/w) of natural liquid pesticide viz, Azadirachta Indica A Juss (neem) seed oil (NSO) per dry weight of urea formaldehyde crosslinked starch (UF-St), guar gum (UF-GG) and UF-(St + GG) matrices Results of swelling and cumulative release kinetics are presented at 35°C for these matrices The static dissolution experiments have been carried out at 35°C for seven days The percentage cumulative release kinetic data have been analyzed using an empirical equation to study the release pattern of NSO through the polymeric membranes employed Transport follows the Super Case II mechanism as tested by an empirical equation It is found that the release of the active ingredient depends upon the type of the matrix and its swelling ability The percentage loading of NSO with different matrices and their density exerted an influence on the release data The FTIR results indicated the absence of chemical interactions between the matrices and the NSO In the majority of cases, entrapment efficiency was generally more than 95% indicating the efficient encapsulation Furthermore, the experimental results are discussed in terms of the nature and the combined effect of the individual matrices as well as the percentage loading of NSO © 1999 John Wiley & Sons, Inc J Appl Polym Sci 73: 2437–2446, 1999

Clumping cellulosic animal litter

Abstract: Clumping cellulosic animal litter comprising a cellulosic substrate coated with a first layer of xanthan gum and a second layer of guar gum and a unique method of making such particles by applying water coatings between application of the two gum layers.

Studies on preparation and emulsifying properties of guar galactomannan ester of palmitic acid

Abstract: Various degrees of palmitoylated guar galactomannan (PGGM) are prepared by a heterogeneous method. Both differential thermal analysis and X-ray diffraction spectra show substituted palmitoyl chains played a role in the new crystallization and the molecular aggregated structure of GGM was changed. Furthermore, the emulsifying properties of both water-soluble and oil-soluble PGGM were investigated in detail. It is demonstrated that PGGM has good emulsifying activity, even in high salt concentration or in acidic pH. In addition, the emulsifying properties of water-soluble PGGM–protein mixture was also studied systematically. It is proven that water-soluble PGGM is a kind of good oil in water (o/w) emulsion stabilizer. With water-soluble PGGM–casein mixture (0.1 wt %) as emulsifier, clove oil–water (v : v, 1 : 9) emulsion had good stability within 4 weeks at room temperature, and the breakage of emulsion was not brought about. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 639–645, 1999

On the one‐phase state of aqueous protein‐uncharged polymer systems: Casein‐guar gum system

Abstract: Although the majority of biopolymers are incompatible in water, systems containing casein molecules and a neutral polysaccharide (guar gum galactomannan) showed phase separation only at an ionic strength above 0.09–0.2. Static light scattering, circular dichroism spectroscopy, velocity sedimentation, viscosimetry, phase analysis in different solvents, and Rosenberg's method were used to estimate the effect of polymer–solvent and polymer–polymer interactions on the phase state of casein-guar aqueous systems. Different solvent conditions were used to try to clarify the nature (electrostatic or nonelectrostatic) of the interaction between the two macromolecular species. Data obtained show that the dominant mechanism controlling the single-phase state at low ionic strength (below 0.01) involves the formation of water-soluble weak interpolymer complexes, which may be destroyed by increasing ionic strength. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 471–482, 1999

Starch Cooking with Limited Water as Affected by Zein and Guar Gum

Abstract: DSC (Differential Scanning Calorimetry) peak temperature of starch was decreased by adding zein, but was increased by adding guar gum. Adding zein increased the initial rate of starch cooking, but adding guar gum decreased it. Kinetic studies were carried out at 115, 125, and 135 degrees C. At 25 degrees C, zein absorbed less water than waxy corn starch, especially at water activities >0.6 where guar gum absorbed more water than starch. The strong binding of water by guar gum increased DSC-peak-temperature and decreased the initial rate of starch cooking. The relatively weak binding of water by zein decreased DSC peak temperature and increased the initial rate of starch cooking. Although water sorption data at cooking temperatures are difficult to measure, the kinetic data at these temperatures and DSC data could be used to supplement the sorption data.

Intestinal contents supernatant viscosity of rats fed oat-based muffins and cereal products

Abstract: The intestinal contents viscosities of oat-based breakfast cereals and muffins were examined. Male Sprague-Dawley rats were adapted for four days to a semipurified diet (AIN-76A). Following an overnight fast, the animals were meal-fed 5 g of either the AIN-76A diet (containing 5% cellulose), the AIN-76A diet containing 2% guar gum, whole-grain oat flour, one of five cereals (corn flakes, cooked oatmeal, uncooked oatmeal, cooked oat bran, or Cheerios), or one of two types of muffins (containing whole-grain oat flour or oatmeal). Two hours after presentation of the meal, the animals were killed, the small intestines removed, and the contents collected. The contents were centrifuged, and the viscosity values of the undiluted supernatants were determined. The supernatant viscosity from rats fed the AIN-76A diet was negligible (<5 mPa·sec), whereas that from rats fed guar gum was high (396 ± 117 mPa·sec). Of the cereals fed, corn flakes resulted in the lowest viscosity (<5 mPa·sec). However, all oat-b...

Keratin treating cosmetic compositions containing amphoteric polysaccharide derivatives

Abstract: A composition for treating keratin substances comprising selected amphoteric polysaccharide derivatives, preferably guar gum which contain a cationic group comprising an amino, ammonium, imino, sulfonium or phosphonium group and an anionic group comprising a carboxyl, sulfonate, sulfate, phosphate or phosphonate group.

Degradation of guar gum by intestinal bacteria

Abstract: Guar gum is widely used in the food industry as a thickening agent. Guar and other galactomannans are ingested as a normal part of the human diet. Guar is completely degraded in the large intestine. Often large amounts of gas are produced. The objective of the study was to determine which species are responsible for the degradation of guar in the GI tract. It was observed that only a limited number of species is able to degrade and ferment guar. Guar degrading strains could be isolated from faecal samples of all volunteers and in 90% of the saliva of volunteers. The main species isolated from humans were Bifidobacterium dentium and Clostridium butyricum. From several samples of animal faeces Streptococcus bovis could be isolated. In addition some strains of Bacteroides ovatus were able to degrade guar to a limited extent. Fermentation resulted in the production of short-chain fatty acids and, when Cl. butyricum was present, in a large gas production. Competition experiments showed that Cl. butyricum degrades guar faster than both other species under simulated physiological conditions. It was concluded that Cl. butyricum is the main guar degrading species and the causative agent of the gas formation after guar intake.

Influence of selected adjuvants on disease severity by Phoma herbarum on dandelion (Taraxacum officinale)

Abstract: Phoma herbarum was evaluated as a potential biological control agent for dandelion (Taraxacum officinale) in turf. A preliminary controlled environment study identified selected adjuvants that enhanced disease severity by P. herbarum. Subsequently, these adjuvants were evaluated for disease enhancement under field conditions. Adjuvants evaluated included gluten flour, liposome, guar gum from ground guar (Cyamopsis tetragonoloba), durum (Triticum durum), and pectin. Regression analysis revealed a significant (P = 0.05) increase in disease severity by P. herbarum when formulated with gluten flour, guar gum, or durum semolina compared to treatment with 20% mycelium in potato (Solanum tuberosum) dextrose broth (PDB) alone. No phytotoxicity to dandelion was observed among the adjuvant controls.

Guar Gum as a Hydrophilic Matrix for Preparation of Theophylline Controlled-Release Dosage Form.

Abstract: Compressed tablets were prepared from theophylline and guar gum. Effect of the viscosity grade of the polymer and polymer content in the tablets on release pattern of theophylline was examined in vitro. Release rate was retarded with increase in polymer content as well as the viscosity grade of polymer. Dissolution profile was independent of pH, while the compression pressure had only marginal effect on release pattern. In vivo crossover study with twelve human volunteers following oral 'administration, shown that guar gum formulation of theophylline is bioequivalent with the marketed product Theodur.

Keratin treating cosmetic compositions containing high ds cationic guar gum derivatives

Abstract: A compatible cosmetic composition for treating keratin substances comprising a cationic guar gum which contains a cationic group selected from the group consisting of amino, ammonium imino, sulfonium or phosphonium groups and wherein the cationic content is represented by a DS of from about 0.25 to 1.0 and an effective surfactant amount of at least one non-ionic or anionic surfactant.

A non-cellulase producing strain of Bacillus subtilis and its potential use in pulp biobleaching

Abstract: A newly isolated strain of Bacillus subtilis produced β-mannanase when cultivated in a medium containing either locust bean gum, konjac mannan or guar gum as a sole carbon source. In contrast, xylanase was produced only when oat spelt xylan or wheat bran was used as a carbon source. The culture supernatant, which contained both β-mannanase and xylanase, was used to biobleach crude paper pulp to 50% gain in brightness.

Viscoelastic Properties of Commercial Plain Yoghurts and Trial Foods for Swallowing Disorders

Abstract: This paper repotrs strain and frequency dependencies of dynamic viscoelasticity of commercial plain yoghurts and trial foods for swallowing disorders. We prepared four test samples adjusting hardness to a level similar to that of commercial plain yoghurts. Guar gum and modified starch were used as ingredients for preparation of two samples, respectively. Commercial plain yoghurts and modified starch samples exhibited viscoelastic behaviors strongly dependent on shear, while they behaved as nearly elastic material in the linear viscoelastic region. These properties are shown to be consistent to the swallowing mechanism to which well organized cooperative motions of several organs are related. Viscoelastic properties of guar gum samples were found to be quite different from those of commercial plain yoghurts, which suggests that modified starch is a better ingredient than guar gum for preparation of test samples and for detailed research on swallowing disorders.