Molecular weight and intrinsic viscosity of konjac gluco-mannan.

Kishida, Noriko; Okimasu, Satoshi; Kamata, Toshihide

doi:10.1271/bbb1961.42.1645

Cited by 32 publications

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“…Amorphophallus konjac, otherwise known as glucomannan, is a dietary fiber consisting of repeating units of B-1,4 D-glucose, and D-mannose and is reported to be the most water-soluble fiber (97%), expanding up to 200 times its original volume when combined with water. 48 It is believed that dietary fibers, including glucomannan, may provoke body weight loss by acting as bulking agents, thereby increasing satiety and reducing caloric intake, ingestion rate, and nutrient absorption. [29][30][31][32][33] Glucomannan is a highly viscous fiber, more so than pectin and 5-fold more than guar gum.…”

Section: Discussionmentioning

confidence: 99%

Effects of a Stimulant-Free Dietary Supplement on Body Weight and Fat Loss in Obese Adults: A Six-Week Exploratory Study

Woodgate¹,

Conquer²

2003

Current Therapeutic Research

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Background: Obesity is a well-established risk factor for cardiovascular disease, diabetes, hyperlipidemia, hypertension, osteoarthritis, and stroke. Stimulants, such as ephedrine and caffeine and their herbal counterparts, have proved effective in facilitating body weight loss, but their use is controversial due to their undesired effects. Other nutraceuticals have shown moderate success in reducing body weight, whereas several other compounds have demonstrated little or no effect. Therefore, a tolerable and effective nutraceutical that can increase energy expenditure and/or decrease caloric intake is desirable for body weight reduction.Objective: The primary purpose of this study was to assess the tolerability and effectiveness of a novel, stimulant-free, dietary supplement containing glucomannan, chitosan, fenugreek, Gymnema sylvestre, and vitamin C on body weight and fat loss and change in body composition in obese adults.Methods: In this single-center, prospective, randomized, double-blind, placebocontrolled study conducted at the University of Guelph (Guelph, Ontario, Canada), obese adults (aged 20-50 years; body mass index [BMI], ≥30 kg/m 2 ) were randomized to the treatment or placebo group. The treatment group received 6 capsules of a dietary supplement containing a proprietary blend of glucomannan, chitosan, fenugreek, G sylvestre, and vitamin C daily for 6 weeks, and the placebo group received 6 capsules of rice flour daily for 6 weeks. Body weight; percentage of body fat; absolute fat mass; lean body mass; BMI; upper abdominal, waist, and hip circumference; and anthropometric measurements were recorded at baseline and at study end. Patients completed daily dietary intake records on days 1 to 3 and days 40 to 42. They also completed weekly activity logs throughout the study.Results D.E. Woodgate and J.A. Conquerto the treatment group (8 women, 4 men) or the placebo group (9 women, 3 men). Two subjects (8.3%; 1 patient [8.3%] from each group) dropped out for personal reasons unrelated to the study. No significant changes in the consumption of total calories; the percentage of calories ingested as carbohydrates, fat, or protein; or activity levels were found in either group throughout the study. Compared with the placebo group, the treatment group lost significantly more body weight (Ϫ2.3 kg vs 0.0 kg; P Ͻ 0.01), percentage of body fat (Ϫ1.1% vs 0.2%; P Ͻ 0.05), and absolute fat mass (Ϫ2.0 kg vs 0.2 kg; P Ͻ 0.001).The treatment group also experienced a significantly greater reduction in upper abdominal circumference (Ϫ4.5 cm vs Ϫ0.7 cm), waist circumference (Ϫ4.1 cm vs 0.1 cm), and hip circumference (Ϫ2.9 cm vs 0.6 cm) compared with the placebo group (P Ͻ 0.05 for all). No significant changes in heart rate or blood pressure were found in either group. Both the treatment and the placebo were well tolerated. Conclusion:Within the context of this study, the novel combination of glucomannan, chitosan, fenugreek, G sylvestre, and vitamin C results in significant body weight and fat loss in obese adu...

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Section: Discussionmentioning

confidence: 99%

Effects of a Stimulant-Free Dietary Supplement on Body Weight and Fat Loss in Obese Adults: A Six-Week Exploratory Study

Woodgate¹,

Conquer²

2003

Current Therapeutic Research

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“…The ratio of mannosyl and glucosyl units was determined to be 1.6 by Kato and Matsuda . The molecular weight is reported to be in the range of 1 × 10 4 to 1.9 × 10 6 . Branching at either position 3 or 6 of both sugar constituents has been reported by some authors, but others did not find any hint on branching at all.…”

Section: Introductionmentioning

confidence: 96%

Influence of Stereochemistry on Relative Reactivities of Glucosyl and Mannosyl Residues in Konjac Glucomannan (KGM)

Zhang

Mischnick

2017

Macromol. Chem. Phys.

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Methylation in water with NaOH/MeI is applied to study the influence of the stereochemistry on relative reactivities of d‐mannosyl (M) compared to d‐glucosyl (G) units in konjac glucomannan (KGM). The pH is kept constant at 13.6 over the course of the reaction and aliquots are removed after various time intervals. Methyl distribution in G and M residues is determined after perethylation, hydrolysis, and conversion to O‐ethyl‐O‐methyl‐alditol acetates. The order of relative rate constants determined for the O‐methyl Konjac glucomannans (M‐KGMs) in degree of substitution (DS) range 0.3–0.8 is G‐k6 > M‐k6 > G‐k2 ≈ M‐k2 > M‐k3 > G‐k3. Oligosaccharides obtained by partial hydrolysis after full protection of M‐KGM with MeI‐d3 are labeled with m‐amino‐benzoic acid and measured by liquid chromatography–electrospray ionization–mass spectrometry. DS/DP profiles are in full agreement with random distribution of methyl groups. Thermal properties of M‐KGMs are analyzed by differential scanning calorimetry and thermogravimetric analysis. Decomposition temperature increases with DS, while the temperature of an endothermic change decreases.

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“…From the concentration of 0.25 g/100 mL, the decrease of the π/c value is less dramatic than for lower concentrations [88]. A negative second virial coefficient would suggest a low affinity of the solvent to the polymer chains, which is due to the low temperature of the osmotic pressure measurement.…”

Section: Osmotic Properties Of Nonstarch Polysaccharides' Solutionsmentioning

confidence: 89%

Osmotic Properties of Polysaccharides Solutions

Kruk¹,

Pancerz²,

Ptaszek³

2017

Solubility of Polysaccharides

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Osmotic properties of polysaccharides' solutions and associated biopolymer-solvent and biopolymer-biopolymer type interaction are very important from a technological point of view. The knowledge of osmotic properties of these systems provides the basis to appropriate use of polysaccharides having comply with the relevant technology functions, impart the appropriate texture and forming the sensory properties of the final product. Furthermore, an important issue is the effect of time on the osmotic properties of polysaccharides', because with time, the aforementioned effects may change. Membrane osmometry is one of the methods used in the studies of synthetic polymers to determine their average molecular mass and the degree of interaction between a polymer and a solvent. This method is successfully applied in the case of biopolymers that include polysaccharides. The existence of the osmotic pressure, formed by diffusion of solvent molecules through a semi-permeable membrane, is the basis of this method. Analysis and interpretation of osmometric research results is based on the van't Hoff equation dependency of the concentration. The second virial coefficient obtained based on this relation allows characterisation of biopolymer-solvent interactions, and thus biopolymer tendency to solvation. The third virial coefficient provides information on mutual interactions between the biopolymer molecules, as well as its tendency to aggregate.

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Molecular weight and intrinsic viscosity of konjac gluco-mannan.

Cited by 32 publications

References 0 publications

Effects of a Stimulant-Free Dietary Supplement on Body Weight and Fat Loss in Obese Adults: A Six-Week Exploratory Study

Effects of a Stimulant-Free Dietary Supplement on Body Weight and Fat Loss in Obese Adults: A Six-Week Exploratory Study

Influence of Stereochemistry on Relative Reactivities of Glucosyl and Mannosyl Residues in Konjac Glucomannan (KGM)

Osmotic Properties of Polysaccharides Solutions

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