Showing papers on "Guar gum published in 1997"

Fenugreek galactomannans as food emulsifiers

Abstract: Fenugreek gum was extracted from fenugreek seeds and evaluated for its surface activity. This unique galactomannan has a mannose backbone grafted with galactose units at an average ratio of one. The purified fenugreek gum was found to reduce surface tension to values lower than guar gum (42 and 55 mN/m, respectively). The interfacial activity was surprisingly better than other galactomannans (interfacial tension was reduced to 2 mN/m in vegetable oils) which led to the formation of oil-in-water emulsions with small droplet size (2–3 μm) and long-term stability. The fenugreek gum was found to adsorb (or ‘precipitate’) on the oil interface forming a relatively thick interfacial film. The emulsions are more stable than any equivalent emulsions stabilized by other galactomannan gums. No flocculation was observed in emulsions stabilized with fenugreek concentrations sufficient for a good coverage of the oil interface as expressed by the coverage index (Rc) correlated to the gum/oil weight ratio (Rc>12).

Effect of Hydrocolloids on Gelatinization and Structure Formation in Concentrated Waxy Maize and Wheat Starch Gels

Abstract: Starch-hydrocolloid interactions were studied in concentrated (40% w/w starch) aqueous dispersions by differential scanning calorimetry and dynamic rheometry. At the levels commonly employed in food product formulations (1–2% w/w hydrocolloid on a starch basis), polysaccharides of varying molecular structures (xanthan, β-glucan, arabinoxylan, guar gum) did not affect the gelatinization temperature of waxy maize and wheat starches. However, the hydrocolloids increased the phase transition temperature range (Tm-Ti) and the melting enthalpy of starch crystallites, implying a stabilization of the granular structures during heating. There was also an enhancement in the crystallization rate of amylopection on aging gels at 5°C, the effect being more marked with the waxy maize starch gels. The most pronounced effect, however, has been the retardation of gelation kinetics of waxy maize starch by the hydrocolloids. The decrease in storage modulus (G′) development of amylopectin-hydrocolloid gels was attributed to the interference of intermolecular associations among amylopectin molecules by the polysaccharide, which seems to be a prerequisite for establishment of a continuous network structure. In contrast, wheat starch gel rheology did not seem to be affected by the hydrocolloids.

Adsorption of Dextrin and Guar Gum onto Talc. A Comparative Study

Abstract: The interaction of guar gum and dextrin with talc has been investigated through adsorption, flotation, and electrokinetic measurements. The adsorption densities are independent of pH and the isothe...

Dietary Guar Gum Improves Insulin Sensitivity in Streptozotocin-Induced Diabetic Rats

Abstract: Although dietary recommendations for diabetics stress the need for increased carbohydrate and dietary fiber, the effectiveness of dietary fiber in improving insulin sensitivity remains controversial. The aim of this study was to compare the effects of a soluble fiber (guar gum) and an insoluble fiber (wheat bran) on insulin sensitivity in streptozotocin-induced (STZ) diabetic rats. Consequently, the rats were divided into two groups and one half were rendered diabetic with streptozotocin. The STZ diabetic and nondiabetic rats were further randomized and fed a diet containing dietary fiber (7 g/100 g diet) from either guar gum or wheat bran. The hyperinsulinemic clamp technique, combined with infusion of the glucose analog, 2-deoxyglucose (2DG), was utilized to examine insulin sensitivity. Bran-fed STZ diabetic rats were significantly (P < 0.001) hyperglycemic, which was ameliorated by guar gum. Insulin-mediated glucose disposal was increased by the guar diet compared with the bran diet in both the STZ diabetic rats [17.7 +/- 2.2 vs. 11.8 +/- 2.4 mL/(kg x min), P < 0.05] and the nondiabetic rats [20.5 +/- 2.8 vs. 15.5 +/- 1.5 mL/(kg x min), P < 0.05]. The accumulation of 2DG in peripheral muscles reflected the changes in insulin sensitivity with a trend for increased 2DG uptake in the majority of analyzed tissues in rats fed the guar diet, both nondiabetic and STZ diabetic, compared with the bran-fed rats. Accompanying these alterations in insulin sensitivity, guar gum suppressed food intake in the hyperphagic diabetic rats by 20% (P < 0.001). The present results demonstrate the effectiveness of guar gum in improving insulin sensitivity in STZ diabetic rats and suggest that reduced food intake may be an important mechanism of action of guar in hyperphagic diabetic rats.

Influence of polymers for use in saliva substitutes on de- and remineralization of enamel in vitro.

Abstract: A number of polymers which have previously been tested for their applicability as thickening agents in saliva substitutes were studied in vitro for their caries-protective properties. These were: polyacrylic acid, carboxymethylcellulose, xanthan gum, guar gum, hydroxyethylcellulose and porcine gastric mucin. The polymers were tested for their effects on: (1) growth of hydroxyapatite crystals in a supersaturated calcium phosphate solution, (2) dissolution of hydroxyapatite crystals in 50 mM acetic acid, pH 5.2 and (3) demineralization and remineralization of bovine enamel in a pH-cycling model. Growth of hydroxyapatite crystals was strongly inhibited by polyacrylic acid and carboxymethylcellulose at very low concentrations (0.005% w/v). Other polymers displayed lower inhibition of hydroxyapatite crystal growth. Hydroxyapatite dissolution was inhibited by all polymers except by hydroxymethylcellulose and xanthan gum. This occurred both in the presence of the polymers as well as after a 30-min preincubation. In the pH-cycling experiment, bovine enamel specimens with preformed lesions were alternately exposed to a demineralization buffer and a remineralization buffer containing the polymers hydroxyethylcellulose, carboxymethylcellulose, xanthan gum, polyacrylic acid, or porcine gastric mucin. A remineralization buffer containing 1 ppm NaF was used as a positive control. Under the experimental conditions, the control experiment without additives resulted in a net mineral loss (30.6 mumol Ca/cm2 after 14 days of pH cycling). In the presence of 1 ppm NaF, a small mineral gain was observed (8.6 mumol/cm2). All polymers largely inhibited further demineralization (1.2-12.3 mumol/cm2) except polyacrylic acid which, inhibited of its high calcium-binding capacity, caused demineralization, especially in the remineralization buffer (17.1 mumol/cm2). In conclusion, polymers tested in this study, except the polyacrylic acid, reduced the demineralization of enamel in vitro. The precise mechanism of the protective effect is not clear but it is speculated that formation of an absorbed polymer layer on the hydroxyapatite or enamel surface may provide protection against acidic attacks.

Effect of Viscous Fiber (Guar) on Postprandial Motor Activity in Human Small Bowel

Abstract: Both caloric value and chemical composition ofa meal have been shown to regulate postprandial smallbowel motility in dog. In the same species, duration ofand contractile activity within the postprandial period also depends on mean viscosity. It isunknown, however, whether meal viscosity and fibercontent also regulate small bowel motor activity in man.In human volunteers, we therefore studied the effect of guar gum on small bowel motor response toliquid and solid meals. Twenty-six prolonged ambulatorysmall bowel manometry studies were performed in 12volunteers. A total of 620 hr of recording were analyzed visually for phase III of the MMC and avalidated computer program calculated the incidence andamplitude of contractions after ingestion of water (300ml), a pure glucose drink (300 ml/330 kcal) or a solid meal (530 kcal) with and without 5 g of guargum. Addition of 5 g of guar gum did not significantlydelay reappearance of phase III after ingestion of water(59 ± 11 vs 106 ± 21 min; P = 0.09).However, guar gum significantly prolonged duration ofpostprandial motility pattern both after the glucosedrink (123 ± 19 vs 199 ± 24 min; P <0.05) and after the solid meal (310 ± 92 vs 419± 22 min; P = 0.005). Contractile activity during these periods was not affected by guargum. This was true for mean incidence of contractionsafter water (1.9 ± 0.3 vs 1.8 ± 0.5min-1), after the glucose drink (1.6 ±0.4 vs 1.7 ± 0.3 min-1) and after the solid meal (2.4 ± 0.4 vs 2.6 ±0.4 min-1). Likewise, mean amplitude ofcontractions was not affected by guar gum after water(22.8 ± 1.4 vs 20.9 ± 1.9 mm Hg), afterthe glucose drink (20.5 ± 1.4 vs 21.3 ±1.2), and after the solid meal (20.3 ± 1.5 vs 21.5± 1.6 mm Hg). Thus a guar gum-induced increase inchyme viscosity markedly prolonged duration ofpostprandial motor activity in the human small bowel.Contractile activity within the postprandial period, however, wasnot affected. We suggest that the postprandial motilitypattern persisted longer after the more viscous meals,because gastric emptying and intestinal transit were delayed by guar gum. We conclude that itis essential to define meal viscosity and fiber contentwhen studying postprandial small bowelmotility.

Viscosity of gums in vitro and their ability to reduce postprandial hyperglycemia in normal subjects

Abstract: Experiments were carried out in vitro with three viscous polysaccharides (guar gum, pectin, and carboxymethylcellulose (CMC) of similar initial viscosity submitted to conditions that mimic events occurring in the stomach and duodenum, and their viscosity in these situations was compared to their actions on postprandial hyperglycemia in normal human subjects. Guar gum showed greater viscosity than the other gums during acidification and/or alkalinization and also showed larger effects on plasma glucose levels (35% reduction in maximum rise in plasma glucose) and on the total area under the curve of plasma glucose (control: 20,314 +/- 1007 mg dl-1 180 min-1 vs guar gum: 18,277 +/- 699 mg dl-1 180 min-1, P < 0.01). Pectin, which showed a marked reduction in viscosity at 37 degrees C and after events mimicking those that occur in the stomach and duodenum, did not have a significant effect on postprandial hyperglycemia. The performance of viscosity and the glycemia response to CMC were at an intermediate level between guar gum and pectin. In conclusion, these data suggest that temperature, the process of acidification, alkalinization and exposure to intestinal ions induce different viscosity changes in gums having similar initial viscosity, establishing a direct relationship between a minor decrease of gum viscosity in vitro and a reduction of postprandial hyperglycemia.

The cholesterol‐lowering effect of guar gum is not the result of a simple diversion of bile acids toward fecal excretion

Abstract: The effects of partially hydrolyzed, nonviscous, guar gum (PHGG) on cholesterol metabolism and digestive balance have been compared with those of native guar gum (GUAR) in rats adapted to 0.4% cholesterol diets. Both types of guar gum elicited acidic fermentations in the large intestine, but only GUAR effectively lowered plasma cholesterol (P < 0.001), chiefly in the triglyceride-rich lipoprotein fraction. The biliary bile acid excretion was significantly enhanced in rats fed GUAR (P < 0.05), as well as the intestinal and cecal bile acid pool (P < 0.001). In rats fed GUAR and to a lesser extent in those fed PHGG, the fecal excretion of bile acids and neutral sterol was higher than in controls (P < 0.01). The digestive balance (cholesterol intake-steroid excretion) was positive in control rats (+47 mumol/d), whereas it was negative in rats fed GUAR (-20 mumol/d), which could involve a higher rate of endogenous cholesterol synthesis. In rats fed PHGG, the steroid balance remained slightly positive. Liver 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity was very low (22 pmol/min/mg protein), owing to cholesterol supplementation, in control rats or in rats fed PHGG, whereas it was markedly higher (+463%) in rats fed GUAR. In conclusion, even if PHGG does alter some parameters of the enterohepatic cycle of cholesterol and bile acids, its effects are not sufficient to elicit a significant cholesterol-lowering effect. The intestinal (ileal or cecal) reabsorption of bile acids was not reduced, but rather increased, by GUAR; nevertheless the intestinal capacities of reabsorption were overwhelmed by the enlargement of the digestive pool of bile acids. In the present model, induction of HMG-CoA reductase probably takes place in the presence of elevated portal bile acid concentrations.

Temporary wet strength paper

Abstract: The present invention relates to paper products having temporary wet strength. The paper products contain cellulosic fibers that are treated with a polyaldehyde polymer having free aldehyde groups and a water soluble polyhydroxy polymer. The initial wet strength obtained with the combined use of these materials is significantly greater than that obtained by use of either the polyaldehyde or polyhydroxy polymer alone. At the same time, the wet strength decays at a rate that is rapid enough to enable the paper product to be flushed under conditions of normal use. Preferred polyaldehydes include cationic, aldehyde functionalized starches and cationic, aldehyde functionalized polyacrylamides. Preferred polyhydroxy polymers are polysaccharides having cis-hydroxyl groups in at least a portion of the main polymeric chain (i.e., polymer backbone). Preferred polysaccharides include those derived from one or more sugars selected from mannose, galactose, allose, altrose, gulose, talose, ribose, and lyxose. Economically preferred polysaccharides are guar gum, locust bean gum and ionic derivatives thereof. The polysaccharide is preferably a neutral polysaccharide or a charge balanced mixture of polysaccharides.

Recrystallization in Sugar/Stabilizer Solutions as Affected by Molecular Structure

Abstract: The influence that a range of polysaccharides (galactomannans) had on ice recrystallization was determined. The concentration dependence of the recrystallization inhibition occurring with locust bean and guar gums was determined. The degree of galactose substitution in a range of enzyme modified guars was dominant in the effect of a galactomannan to inhibit recrystallization. The fine structure of the substituents were less important. Where the galactose content of comparable polysaccharides was similar the fine structure became dominant. The influence of sugar size on recrystallization was also investigated. Increasing molecular weight resulted in reduced recrystallization rates. The observed rates appeared to follow Williams-Landell-Ferry kinetics.

Temporary wet strength additives

Abstract: Compounds comprising the oxidation product of a polysaccharide in which the hydroxyl groups in at least a portion of the repeating units of the polysaccharide are cis-hydroxyl groups, the oxidation product comprising aldehyde groups, are disclosed. The compounds are useful for imparting temporary wet strength to paper products. Preferred polysaccharides for use in the invention include guar gum and locust bean gum.

Solid polysaccharide materials for use as wound dressings

Abstract: Solid, bioabsorbable materials for use as wound dressings comprise at least 50% by weight of a mixture of xanthan and at least one galactomannan, such as guar gum or locust bean gum. The weight ratio of xanthan: total galactomannans is in the range 1:99 to 99:1, preferably 10:99 to 99:10. The material is preferably made in the form of a sponge by freeze drying a mixed aqueous gel of the xanthan and galactomannans.

Derivatized guar gum composition including nonionic and cationic groups which demonstrate excellent solution clarity properties for detergent applications

Abstract: Nonionic and cationic derivatized guar gum which demonstrates greater than 75 % light transmission at a wavelength of from about 500-600 nanometers when dispersed in water in the amount of 0.5 parts per 100 parts water and the process for producing such guar gum is disclosed. The compositions are particularly useful for producing products having utility in personal care and industrial cleaning products.

Cosmetic composition based on guar gum and silicones

Abstract: A non-washing cosmetic composition comprising, in a cosmetically acceptable medium, at least one guar gum and at least one oxyalkylenated silicone in a guar gum/silicone weight ratio of less than or equal to 5:1, and a process for the treatment of the skin or keratinous fibres comprising the step of applying a non-washing cosmetic composition as defined above to the skin or to the keratinous fibres and optionally rinsing the skin or keratinous fibres with water.

Effect of Dietary Fiber on Bowel Mucosal Integrity and Bacterial Translocation in Burned Rats.

Abstract: The response of the bowel mucosa to enteral formula supplemented with dietary fiber was examined in rats with 30% full-thickness burns. The rats were fed a standard enteral formula without fiber or with one of two types of fiber (insoluble soy fiber or soluble guar gum fiber). Seventy-two hours after burn injury, the mesenteric lymph nodes were excised aseptically for bacterial culturing. Samples of the jejunum, ileum and cecum were also collected for histological examination. There were significantly fewer bacterial colonies in the lymph node cultures from rats given soy fiber compared to those from rats fed no fiber. In rats given soy fiber, the integrity of the bowel mucosa was maintained in the jejunum, ileum and cecum. In rats given guar gum fiber, however, the repair of mucosal erosions was observed in the jejunum and ileum as well as flattening of the cecal mucosa. These findings indicate that soy fiber is superior to guar gum fiber for maintaining bowel mucosal integrity and preventing bacterial translocation in burned rats receiving enteral feeding.

High viscosity crosslinked gelled alcohol

Abstract: A fracturing fluid composition for use in fracturing underground formations, such as oil or gas wells is described. It includes at least one anhydrous aliphatic alcohol, a modified guar gum polymer, and as a complexor, a sodium borate salt. A gel breaker which acts over a time period to degrade the guar gum cross linked polymer and thereby reduce the viscosity of the gel is provided as well to aid in the removal thereof from an oil or gas well that has been fractured by application of the fluid under pressure.

Purification, properties, and N-terminal amino acid sequences of guar gum-degrading enzyme from Bacillus circulans K-1.

Abstract: A guar gum-degrading enzyme of the newly isolated Bacillus circulans K-1 was purified to an electro-phoretically homogeneous state. The molecular weight of the purified enzyme was 62,000 by SDS-PAGE. The purified enzyme was separated into at least six isozymes by isoelectric focusing and the pI of these isozymes were 5.4, 5.5, 5.6, 5.8, 6.0, and 6.2, respectively. The N-terminal amino acid sequences of the typical three of these proteins were all the same, Ala-Ser-Gly-Phe-Tyr-Val-Ser-Gly-Thr-Lys-Leu-Leu-Asp-Ala-Thr-Gly-Gln-Pro-Phe-Val-Met-Arg. The enzyme was most active at pH 6.9 and at 64°C. The enzyme was activated slightly by Al3+ and inhibited strongly by Sn2+ and Zn2+, N-bromosuccinimide, 2-mercaptoethanol, and ethylenediamine-tetraacetic acid.

Wheat flour product

Abstract: PROBLEM TO BE SOLVED: To obtain a wheat flour product having a moist, soft and crispy texture having preferable elasticity by including thickening polysaccharides in a raw material dough for the wheat flour product. SOLUTION: Glucomannan and at least one kind of thickening polysaccharide selected from gelatin, agar, carrageenan, xanthane gum, guar gum, Tara gum, locust bean gum, gellant gum, carboxymethylcellulose, pectin, pullulan, and alginic acid, preferably carrageenan, xanthane gum, guar gum and gellant gum, are contained in a total amount of 0. 1-5. 0% based on all grain flours used in the wheat flour product.