Rheological properties of a polysaccharide isolated from Adansonia digitata leaves

Nwokocha, Louis M.; Williams, Peter

doi:10.1016/j.foodhyd.2016.02.013

Cited by 40 publications

(17 citation statements)

References 22 publications

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“…The other molar mass distribution obtained from the FSG measured in g/mol were as follows; Mn (7.80 × 10 5 ), Mw (1.32 × 10 6 ), Mz (1.88 × 10 6 ), Mη (1.24 × 10 6 ), and the polydispersity values of Mw/Mn and Mn/Mz were 1.6 and 2.4, respectively. The polydispersity value of Mw/Mn (1.6) indicates a narrow range of mass distribution of polysaccharides (Nwokocha & Williams, ). Likewise, Elboutachfaiti et al () inspected Mw, Mn, and polydispersity values of flaxseed mucilage as 1.23 × 10 6 , 8.21 × 10 5 g/mol, and 1.49, respectively that were found relatively closer to the current results.…”

Section: Resultsmentioning

confidence: 99%

Flaxseed gum: Extraction, bioactive composition, structural characterization, and its potential antioxidant activity

et al. 2019

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Flaxseed gum (FSG) is a heteropolysaccharide consist of neutral and acidic components that makes up approximately 8% of seed mass. FSG was extracted from mixture of brown and golden varieties of flaxseeds by hot water extraction method. The molecular weight distribution, monosaccharide analysis, chemical composition, and surface morphology of FSG were scrutinized in the current study to get a better insight regarding this important polysaccharide. The average molecular weight was recorded as 1,322 kDa with a polydispersity ratio of 1.6 for Mw/Mn and 2.4 for Mn/Mz. High‐performance liquid chromatography (HPLC) screening revealed that extracted FSG was comprised of rhamnose, arabinose, mannose, glucose, fucose, xylose, galactose, glucosamine, glucuronic acid, and galacturonic acid, of which mannose and glucosamine have not been reported previously. The antioxidant activities of FSG measured as DPPH, ABTS, reducing power, and total antioxidant activity clearly demonstrated the antioxidant potency of FSG. Fourier‐transform infrared spectroscopy (FTIR) and the Nuclear magnetic resonance (NMR) (1H, 13C) s pectra ratified the presence of functional groups typical for polysaccharide. Practical applications Flaxseed gum is a natural carbohydrate polymar. This study provides useful information regarding antioxidant potential, chemical, and structural characterization of FSG. The availability of a gum is fully characterized with bioactive composition, structural features, and antioxidant potential provides a toolset for the practical application in the food or drug industry.

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Section: Resultsmentioning

confidence: 99%

Flaxseed gum: Extraction, bioactive composition, structural characterization, and its potential antioxidant activity

et al. 2019

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“…The result showed that increasing the inclusion level of GO increased the viscosity of KGM/GO sol. According to literature, the degree of polymer chain entanglements has been an important decisive factor for viscosity. Viscosity increases with increase in the KGM molecular chain entanglements.…”

Section: Resultsmentioning

confidence: 99%

“…The shear‐thinning behavior occurred due to the orientation of the polymer molecular chain in the flow field and fewer interactions among adjacent polymer chains. The increase in shear rate increases the degree of polymer molecular chain orientation, which in turn decreases the viscosity …”

Section: Resultsmentioning

confidence: 99%

The effects of graphene oxide on the properties and drug delivery of konjac glucomannan hydrogel

Yuan

Yan

et al. 2017

J of Applied Polymer Sci

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Konjac glucomannan (KGM) hydrogel has good potential application in food and medical science, although to achieve this, the physical and mechanical properties need further improvement. In this study, graphene oxide (GO) was used to improve the functionality of KGM hydrogel. KGM/GO hydrogels were prepared by freezing the alkaline KGM/GO sols. Rotational rheometer was used to study the rheological properties of different alkaline KGM/GO sols. Fourier transform infrared, Raman, differential scanning calorimetry, thermogravimetric analyses, and scanning electron microscopy were used to evaluate the structure and properties of the hydrogels. In addition, different pH solutions and an in vitro assay were used to study the swelling property and the release behavior of KGM/GO hydrogels, respectively. The result revealed strong hydrogen-bond interaction between KGM and GO. The incorporation of GO highly improved the gel properties of KGM/GO sol, higher thermal stability, and more compact structure of KGM/GO hydrogels. KGM/GO hydrogels showed better swelling properties in deionized-distilled water and pH 7.2 PBS. The release of 5-aminosalicylic acid (5-ASA) from KGM/GO (KG4) hydrogel was different in various pH media, but the initial burst release effect was very severe. Therefore, incorporation of GO have a good potential in enhancing the properties of KGM hydrogel, but KGM/GO hydrogel is not an ideal carrier for 5-ASA release.

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“…The thermal stability of natural polymers is attributed to intramolecular attraction forces such as hydrogen bonds and Van der Waals force, while methyl and hydroxyl groups, as well as hemiacetal atoms, contribute to chain stability (Tako, 2015). The increase in temperature weakens the intra-and intermolecular attraction forces and results in the disorientation of polymeric chains, which leads to lower dispersion viscosity (Eren et al, 2015;Nwokocha and Williams, 2016). Particularly for polysaccharides, that effect also depends on the solution concentration, i.e., the higher the dispersion concentration, the lower the dependence on temperature with the molecular mobility of the polymer (Li and Nie, 2016), which can be seen in the slopes of the lines in Fig.…”

Section: Influence Of Temperature and Concentration On Bg Rheologymentioning

confidence: 99%

“…E a represents the energy barrier to be overcome for flow to occur (Gong et al, 2012;Rao, 2013) and the higher its value, the greater the influence of temperature on product viscosity (Silva et al, 2005). The reduction in E a value as the BG dispersion concentration increases can be explained by the fact that the higher the concentration, the greater the inter-and intramolecular interactions of the polymer, thus inhibiting hydration with the consequent reduction of polymer breakdown, which contributes for viscosity to be less sensitive to temperature (Gong et al, 2012;Nwokocha and Williams, 2016).…”

Section: Influence Of Temperature and Concentration On Bg Rheologymentioning

confidence: 99%

Colloidal and rheological behavior of aqueous dispersions of buriti tree (mauritia flexuosa) gum

2017

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The temperature, concentration and pH variables influence the aqueous dispersion of the gum properties. In this context, the aims of this research were to characterize the gum obtained from the buriti tree (Mauritia Flexuosa) trunk exudate, as well as to evaluate the colloidal and rheological behavior of the aqueous dispersions of this gum. Thus, the centesimal composition, absolute zeta (ζ) potential as a function of pH (1.2 to 4.0), particle size distribution, as well as the rheological properties of the gum at different temperatures (15, 20, 25, 30, and 40 °C) and concentrations (4, 5, 8, and 10% (m/v)) were studied. In addition, the Newton, Power Law, and Herschel-Bulkley models were fitted to the rheological data. Buriti tree gum (BG) was found to have 10.43% moisture, 5.05% ashes, 0.68% lipids, 3.09% proteins, and 80.76% carbohydrate. The aqueous dispersion of the gum (1%) had a ζ value of -17.1 mV with a tendency for greater stability at pH < 4 and polydisperse particle size distribution (45 nm to 648.1 nm diameter) with PDI (polydispersity index) of 1. The aqueous dispersion with 4 and 5% gum had typical Newtonian fluid behavior and became pseudoplastic at concentrations of 8 and 10%. The Herschel-Bulkley model had the best fit to the rheological data (r2 > 0.99). Gum dispersion viscosity decreased with higher temperature and lower concentration. The activation energy (Ea) value for gum dispersion ranged from 9.07 to 17.35 kJ/mol.

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Rheological properties of a polysaccharide isolated from Adansonia digitata leaves

Cited by 40 publications

References 22 publications

Flaxseed gum: Extraction, bioactive composition, structural characterization, and its potential antioxidant activity

Flaxseed gum: Extraction, bioactive composition, structural characterization, and its potential antioxidant activity

The effects of graphene oxide on the properties and drug delivery of konjac glucomannan hydrogel

Colloidal and rheological behavior of aqueous dispersions of buriti tree (mauritia flexuosa) gum

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