Biophysical investigation of plant exudate of Acacia senegal (L) Willd. from Sudan-savannah ecological zone of Nigeria (original) (raw)
Related papers
Characterisation and molecular association of Nigerian and Sudanese Acacia gum exudates
Food Hydrocolloids, 2015
The chemical and physicochemical characteristics of gum exudate samples harvested from mature trees of Acacia senegal at two new specific ecolocations in Nigeria, have been investigated together with gum samples harvested from Acacia senegal and Acacia seyal originating from Sudan. The monosaccharide sugar compositions for the Acacia senegal gum samples were found to be similar, but the protein contents for the Nigerian samples were significantly higher than recorded for the Sudanese sample. Gel Permeation Chromatography coupled to light scattering, refractive index and U.V. detectors, has shown the presence of arabinogalactan, arabinogalactanprotein and glycoprotein fractions within the Acacia senegal gums and has also shown the presence of an additional small proportion of very low molar mass proteinaceous material all the samples which has previously been ignored. The plot of radius of gyration, Rg, as a function of elution volume showed a discontinuity for one of the Nigerian samples and for the Acacia seyal gum sample at elution volumes corresponding to the AGP component suggesting a different molecular structure. Plots of Mw-v-Rg confirmed that the molecules had a compact structure. The hydrodynamic size of the molecules was followed using dynamic light scattering as a function of time and it was found that molecular association occurred in solution. The extent of association increased as the protein content in the sample increased and was inhibited in the presence of electrolyte, it was concluded that association was due to electrostatic interaction between the protein moieties and glucuronic acid groups on individual macromolecules.
Food Chemistry, 2008
Gum exudates from Acacia drepanolobium and A. kirkii ssp. kirkii var. kirkii from Tanzania have been analyzed and the intra-species variation of their properties evaluated. The results show that inter-species variation of the properties of the gum exudates from the two species exist, whereas only some parameters show intra-species variation. The specific optical rotations of the gum exudates varied from +72.0°to +94.6°for A. drepanolobium and +29.2°to +38.0°, for A. kirkii ssp. kirkii var. kirkii. Likewise, the acid equivalent weights (AEWs) varied from 832 to 1659 for A. drepanolobium and 663 to 1199 for A. kirkii ssp. kirkii var. kirkii. Intra-species variation for the tannin content was also observed for the species studied, whereas no intra-species variation was observed for the nitrogen and methoxyl contents. The results in this study show that the variation of the properties among the batches of commercial Acacia gum may be due to admixture of gums from different Acacia species, as well as intra-species variation.
Assessing the suitability of locally produced gum exudates in the food industry
The over-reliance of the food industry in Ghana on imported gums ultimately increases the final cost of processed food. Gums produced by some trees in Ghana have not been exploited commercially, probably due to lack of data on the properties which influence their application in the food industry. This study was therefore undertaken to assess the suitability of gums obtained from Cashew, Albizia, and Khaya trees in Ghana in food applications, using Acacia gum as a control. The properties studied include organoleptic, pH, solubility, viscosity, swelling power, and water binding capacity. The physicochemical properties were determined through experimentation and observation. The pH, viscosity, swelling power and water binding capacity of the gums were 3.80-5.00, 93.0-11195.0 mPas (at 3% concentration), 1.64-20.56% and 4.0-428.8%, respectively. Cashew gum showed similar properties as Acacia gum, and can be used as a substitute for Acacia gum. Albizia gum was found to have the highest viscosity and water binding capacity, followed by Khaya gum, and thus has the potential to be used as a thickener in jams, sauces, etc., and also prevent stalling in baked goods and crystallization in confectioneries. The acid stabilities of Cashew and Albizia gums were comparable with that of Acacia gum.
Studies on Acacia exudate gums: Part VI. Interfacial rheology of Acacia senegal and Acacia seyal
Food Hydrocolloids, 2008
The effect of concentration, ageing and enzyme degradation on the interfacial rheology at the liquid/air (L/A) and liquid/liquid (L/L) interface of aqueous solutions of the gum exudates from Acacia senegal and Acacia seyal have been studied. Both gums had film forming capabilities which increased as a function of time and concentration. The interfacial elasticity of the A. senegal gum samples was greater than that of the A. seyal gums and increased with increasing arabinogalactan protein (AGP) content of the A. senegal gums and their overall protein content. When the AGP was degraded by proteolytic enzyme the interfacial viscoelasticity was lost for both A. senegal and A. seyal gums. The different interfacial elasticity and viscosity of these two gums at the oil-water interface may reflect their well known differing abilities to maintain long term emulsion stability. r
Fractionation and Physicochemical Studies of Some Acacia Gums
2009
The chemical and physicochemical characteristics of five authenticated A. senegal gum samples from trees of varying age have been investigated. A. senegal was fractionated by a successive non-solvent fractionation technique using ethanol and acetone as a fractionation agent separately. The fractions were found to be different from the whole gum in terms of molecular characteristics. The molecular mass distribution was determined by gel permeation chromatography (GPC-MALLS) with on-line monitoring using light scattering, refractive index and UV absorbance detectors. The result shows that three main component designated arabinogalactane protein (AGP), arabinogalactane (AG) and glycoprotein (GP) known to be present in A. senegal could be present in their fractions. The weight average molecular weight of A. senegal ranged from 0.808-1.334 X 10 6 g/molwith M w /M n ranged from (2.89-4.42). The SG4 15-20 sample that from the 10-15 years old tree shows high molecular weight, high viscosity and produce emulsion which were stable under accelerate stress condition. All ethanol fractions and (SG-F1A and SG-F3A) gave the best emulsification performance and stability than the starting material (SG-control) dependent on the protein distribution and its association with the high molecular weight fraction (AGP). All emulsion of ethanol and acetone fractions of A. senegal show low degrees of polydispersity and droplet size compared to the starting material indicating uniformity, clean fractionation and increased adsorption of protein on the oil droplet surface.
Characterization and functional properties of some natural Acacia gums
Journal of the Saudi Society of Agricultural Sciences, 2018
Authentic representative gum exudate samples from Acacia species namely Acacia senegal var. senegal (ASG), Acacia mellifera (AMF), Acacia seyal var. seyal (ASY), and Acacia tortilis var. raddiana (ATR), were physicochemically analyzed. The moisture, ash, nitrogen and protein content, pH, specific optical rotation, and number average molecular weight were found to be ranging from 9.76% to 8.35%, 3.40% to 2.05%, 0.243% to 1.549%, 1.610% to 10.378%, 4.45 to 4.94, À48.25 to +86.75 and 0.24 Â 10 6 to 2.95 Â 10 6 respectively. The 13 C and 1 H NMR spectra of gum samples showed similarity in individual sugar components, but characteristic patterns of each gum, were observed. FTIR spectra of the studied gums show the presence of the same functional groups in the four gums. DSC and TGA thermograms were characteristic for each gum. Evaluation of the functional properties of the four gums indicated that ATR gum bears the best emulsification characteristics in terms of emulsion's stability and emulsification power.
Food Hydrocolloids, 2005
Previous research on the binding and gelation of calcium/alginate in aqueous solution were mostly conducted in the (semi-)concentrated regime, and it did not provide details of the binding process and the formation of egg-box junctions. In the present investigation, the binding of calcium to alginate, of low and high molecular weight and different guluronate/mannuronate ratios, was investigated in dilute solutions using isothermal titration calorimetry (ITC), Ca 2+ -selective potentiometry, and viscometry techniques. The results reveal three distinct and successive steps in the binding of calcium to alginate with increased concentration of Ca ions. They were assigned to (i) interaction of Ca 2+ with a single guluronate unit forming monocomplexes; (ii) propagation and formation of egg-box dimers via pairing of these monocomplexes; and (iii) lateral association of the egg-box dimers, generating multimers. The third step has different association modes depending on the molecular weight of alginate. The boundaries between these steps are reasonably critical, and they closely correlate with the Ca/guluronate stoichiometry expected for egg-box dimers and multimers with 2/1 helical chains. The formation of egg-box dimers and their subsequent association are thermodynamically equivalent processes and can be fitted by a model of independent binding sites. The binding of Ca to alginates of different guluronate contents is controlled by a balance between enthalpy and entropy.
2017
A study was conducted to investigate the effect of growing location in the physico-chemical properties of gum arabic obtained from Acacia senegal. Authentic representative gum exudates samples were collected from Abederafi, Yabello, Awash, and Filtu areas of Ethiopia. The experiment was conducted to determine Moisture content (MC), Ash content (Ash), pH, Relative Viscosity (RV), Nitrogen (N), Crude Protein (CP), and Mineral contents. Laboratory analyses were employed to determine the physico-chemical characteristics. The results were analyzed by using SAS Statistical Software. The analysis indicated that very high significant differences (p < 0.001) were seen on Ash, pH, RV, iron, calcium, and sodium contents of the gum-arabic samples between the study sites. Furthermore, significant differences (p < 0.05) were indicated for N, CP, Cu, and K contents. The results also showed MC, Mn, and Mg contents have no significant difference among growing locations. According to our result...
Owusu et at 2016 Assessing the suitability of locally produced gum exudates in the food industry.pdf
The over-reliance of the food industry in Ghana on imported gums ultimately increases the final cost of processed food. Gums produced by some trees in Ghana have not been exploited commercially, probably due to lack of data on the properties which influence their application in the food industry. This study was therefore undertaken to assess the suitability of gums obtained from Cashew, Albizia, and Khaya trees in Ghana in food applications, using Acacia gum as a control. The properties studied include organoleptic, pH, solubility, viscosity, swelling power, and water binding capacity. The physicochemical properties were determined through experimentation and observation. The pH, viscosity, swelling power and water binding capacity of the gums were 3.80-5.00, 93.0-11195.0 mPas (at 3% concentration), 1.64-20.56% and 4.0-428.8%, respectively. Cashew gum showed similar properties as Acacia gum, and can be used as a substitute for Acacia gum. Albizia gum was found to have the highest viscosity and water binding capacity, followed by Khaya gum, and thus has the potential to be used as a thickener in jams, sauces, etc., and also prevent stalling in baked goods and crystallization in confectioneries. The acid stabilities of Cashew and Albizia gums were comparable with that of Acacia gum
International Journal of Applied Agricultural Sciences, 2019
The physicochemical properties of the natural Gum are very important in determining their commercial value and their use. Herein, the present study aims to identify differences in physicochemical properties of Kakamut Gum (Acacia polyacntha) and Hashab Gum (Acacia Senegal). Samples of Gums were collected as follows: Kakamut Gum from Um fakarin forest and Hashab Gum from Eldemokeya forest, North Kordofan State 2008-2009. The two samples were subjected to laboratory analyzed in Warm Seas Agro Business, Elobeid Agricultural Research Station, and Sudanese Standards and Metrology Organization. The study revealed that there were significant differences (p < 0.01) in moisture (dry matter) and optical rotation. Also, significant differences (p < 0.05) were found in the percentage of ash content and viscosity. However, there were no significant differences found in the percentage of the crude fiber, nitrogen (protein), pH, and purity between the two samples. The results obtained demonstrate clearly the physical and chemical characteristics of the two Gums samples and also, throw lights on their nutritional purposes. As well as the study of the physicochemical properties of Kakamut Gum and compare it with Hashab Gum, proved the potential contribution of the Kakamut tree (Acacia Polyacantha) in the Gum production and not depend solely on the Gum produced from the Hashab tree (Acacia Senegal).