Acacia Senegal Gum Research Articles

Facile synthesis and optimization of Acacia senegal gum hydrogel for kinetically treated adsorptive removal of targeted industrial effluents

This context summarizes a detail on the fabrication of Acacia senegal Gum Hydrogel (ASGh) within well-engineered microemulsion, and thereafter chemical modification for environmental remediation. In brief, Divinylsulfone was used to crosslink polymeric chains and produce ASGh in ˂50 μm size within the reverse-microemulsion of Natrium-bis-(2-ethylhexyl) sulfosuccinate in gasoline. ASGh were subjected to chemical modification via versatile diethylenetriamine to produce m-[ASGh] for adsorptive removal of methyl orange (MO), eosin Y (EY) and congo red (CR) from waste-water. ASGh and m-[ASGh] were characterized through Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and zeta potential measurements. For instance, FT-IR spectra depicted new bands upon Diethylenetriamine modification. The zeta potential measurements confirm a positively charged surface of m-[ASGh] upon Diethylenetriamine addition. Interestingly, 0.05 g m-[ASGh] demonstrated 91.0, 84.1, and 73.0 % removal efficiency towards MO, EY and CR, respectively in 2 h equilibrium time. Langmuir, Freundlich and modified-Freundlich isotherms were applied to further delineate adsorption data. Modified-Freundlich model depicted comparatively more agreeable fit, and delivered R2 value nearer to unity. Further, 143 mg·g−1, 130 mg·g−1 and, 116 mg·g−1 maximum adsorption capacity (QM) was represented by m-[ASGh] towards MO, EY and CR, respectively in 2 h. Interestingly, real water sample were tested whereby, the QM against MO, EY and CR was 146 mg·g−1, 132 mg·g−1 and, 111 mg·g−1, respectively in 2 h equilibrium time. To conclude, m-[ASGh] could be treated as decolorizing agent in real waste-water polluted through negatively charged organic pollutants, particularly MO.

In Situ ATR Spectroscopy Study of the Interaction of Acacia senegal Gum with Gold Nanoparticles Films at the Solid-Liquid Interface.

The adsorption process of Acacia gum (A. senegal), a complex heteropolysaccharide, was followed by using a spectroscopic method to unravel the relative contribution of the protein moieties and the carbohydrate blocks on the adsorption process. In situ ATR-FTIR was used to investigate the kinetics and conformational changes associated with the adsorption of A. senegal gum on gold nanoparticle films (Au-NPs) at different pHs. The results of this thorough study highlighted the adsorption of A. senegal gum through its protein moieties, in particular, AGPs of low molecular weight and high protein content, close to the Au-NPs surface. Isotherm experiments, by gradually increasing the concentration, showed that the gum adsorption was heterogeneous and followed the Freundlich model for the amide part, while the polysaccharide part followed the Langmuir model. In addition, the hydration and structural organization of the gum layer depended on the gum concentration. A. senegal gum adsorbed irreversibly on Au-NPs whatever the pHs, but the adsorbed layer presented a different behavior depending on pH. A more aggregated and less hydrated structure was observed at acidic pH, while a very hydrated and continuous layer was detected at higher pH. The secondary structure analysis through amide III band revealed a change in the gum secondary structure at high pH with the increase in β-turn while random coil decreased.

Surface modified Acacia Senegal Gum based spherical hydrogel; fabrication, characterization, and kinetically optimized waste water treatment with remarkable adsorption efficiency

Acacia Senegal Gum hydrogel (HASG) with swollen dimension less than 50 μm were fabricated, and chemically modified with versatile diethylenetriamine (d-amine) to tailor the surface properties for environmental remediation.Negatively charged metal ions, for example, chromate (Cr(III)), dichromate (Cr(VI)), and arsenate (As(V)) were removed from aqueous media by using modified hydrogels (m-HASG). The FT-IR spectra revealed some new peaks due to d-amine treatment. The zeta potential measurements confirm a positively charged surface of HASG upon d-amine modification at ambient conditions. The absorption studies revealed that 0.05 g feed of m-(HASG) possesses 69.8, 99.3, and 40.00% cleaning potential against As(V), Cr(VI), and Cr(III), respectively with 2 h contact time in deionized water. Almost comparable adsorption efficiency was achieved by the prepared hydrogels towards the targeted analytes dissolved in real water samples. Adsorption isotherms, for example, Langmuir, Freundlich and modified Freundlich isotherms were applied to the collected data. Briefly, Modified Freundlich isotherm manifested comparatively agreeable line for the all adsorbents pollutants with highest R2 figure.In addition, maximum adsorption capacity (Qm) with 217, 256, and 271 mg g−1 numerical values were obtained against As(V), Cr(VI), and Cr(III), respectively. In real water samples, 217, 256, and 271 mg g−1 adsorption capacity was represented by m-(HASG).In brief, m-(HASG) is a brilliant material for environmental application as cleaner candidate towards toxic metal ions.

Temperature Effects on the Corrosion Inhibition of Mild Steel in Sulfuric Acid Solution by Acacia senegal Gum with Halide Ions

The effects of temperature on the inhibitive effect of naturally occurring Acacia senegal gum exudate on the corrosion of mild steel in sulfuric acid was studied between 35 and 70 °C using electrochemical impedance spectroscopy and potentiodynamic polarization methods. Findings showed that Acacia senegal gum exudate decreases the corrosion rate of mild steel. The inhibition efficiency declined with raising temperature above 35 °C. The increase in the corrosion rate with increasing temperature was observed for both uninhibited and inhibited systems. Addition of halide ions to the Acacia senegal gum exudate solution enhanced the corrosion inhibition efficiency because of synergistic effects, achieving higher performance with iodide ions as compared to bromide ions. However, the synergistic effects declined above 35 °C up to 70 °C due to temperature effects. It has been observed that increasing temperature adversely affected inhibition efficiencies of both Acacia senegal gum exudate and the synergy between Acacia senegal gum exudate and halide ions. Corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudate and the synergistic effects of halide ions from polarization and impedance measurements were consistent.
 Keywords: temperature, corrosion, mild steel, synergistic effects, Acacia senegal, gum exudate.

Acacia senegal gum attenuates systemic toxicity in CCl4-intoxicated rats via regulation of the ROS/NF-\u03baB signaling pathway

Acacia senegal (AS) gum (Gum Arabic) is a natural emulsifier exudate from the branches and trunk of Acacia trees and it is recognized by the Food and Drug Administration (FDA) agency as a secure dietary fiber. The present research evaluated the systemic oxidative and necroinflammatory stress induced by CCl4 administration and the alleviating effect of AS gum aqueous extract (ASE, 7.5 g/Kg b.w.). The results demonstrated the presence of certain phenolic compounds in ASE, as well as its in vitro potent scavenging ability against ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), NO, and lipid peroxide radicals. Also, the outcomes revealed an improvement in the CCl4-induced liver, lung, brain, and spleen toxicity by reducing the levels of ROS, lipid peroxidation, NO, and the gene expression of NF-κB and its relevant ROS-mediated inflammatory genes. In contrast, the total antioxidant capacity (TAC), as well as the enzymatic and non-enzymatic antioxidants, were significantly upregulated in these organs after the treatment with ASE. These results were confirmed by improving the morphological features of each organ. Therefore, ASE can ameliorate the systemic toxicity caused by CCl4 via regulation of the ROS/NF-κB signaling pathway in the rat organs, which is owed to its phytochemical composition.

Adsorption Behavior of Arabinogalactan-Proteins (AGPs) from Acacia senegal Gum at a Solid-Liquid Interface.

Adsorption of five different hyperbranched arabinogalactan-protein (AGP) fractions from Acacia senegal gum was thoroughly studied at the solid-liquid interface using a quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance (SPR), and atomic force microscopy (AFM). The impact of the protein/sugar ratio, molecular weight, and aggregation state on the adsorption capacity was investigated by studying AGP fractions with different structural and biochemical features. Adsorption on a solid surface would be primarily driven by the protein moiety of the AGPs through hydrophobic forces and electrostatic interactions. Increasing ionic strength allows the decrease in electrostatic repulsions and, therefore, the formation of high-coverage films with aggregates on the surface. However, the maximum adsorption capacity was not reached by fractions with a higher protein content but by a fraction that contains an average protein quantity and presents a high content of high-molecular-weight AGPs. The results of this thorough study highlighted that the AGP surface adsorption process would depend not only on the protein moiety and high-molecular-weight AGP content but also on other parameters such as the structural accessibility of proteins, the molecular weight distribution, and the AGP flexibility, allowing structural rearrangements on the surface and spreading to form a viscoelastic film.

Physicochemical and rheological properties of Acacia Catechu exudate gum

Over 900 species of Acacia trees are found on earth; most of them produce gums. But gums obtained from Acacia senegal and Acacia seyal were explored scientifically and used commercially compared to other species. Acacia Catechu is one of the gums-producing species of the Acacia family found in the India and Indian subcontinent and has not been studied extensively compared to commercial Acacia gum. The present work is aimed to study the physicochemical, rheological properties of Acacia catechu gum (ACG) and compare them with commercial Acacia senegal gum (CAG). ACG is a 1.17 × 105Da molecular weight polysaccharide and is mainly composed of galactose (29.8%), arabinose (19.5%), and rhamnose (18.2%). Further functional property studies showed that ACG has alike film-forming property as CAG. The rheological study indicates that ACG also gives less viscosity at a higher concentration as CAG. Where the effect of NaCl, sucrose, glucose, and fructose addition in gum solution of flow behavior also showed a similar effect on the flow behavior of ACG as showed on CAG. The obtained results help in understanding the behavior of Acacia catechu gum and its possible uses.

Synergistic effects of halide ions and Acacia senegal gum on the corrosion inhibition of mild steel in sulfuric acid solution

The synergistic effects of halide ions, Br– and I– and Acacia senegal gum exudates on the corrosion inhibition of mild steel in 0.5 M sulfuric acid solution has been investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy techniques. Results showed that Acacia senegal gum exudate moderately reduces the corrosion rate of mild steel. The inhibition efficiencies on mild steel electrodes increased with increase in gum exudate concentrations up to 300 ppm, corresponding to the inhibition efficiency of about 43% and its inhibition efficiency increased up to 81.6% with addition of halide ions due to synergistic effects. The enhancement effect of the halide ions was higher with iodide than with bromide ions. The synergism parameter, S1, evaluated was greater than unity, consistent with synergistic effect. The adsorption of Acacia senegal gum on the mild steel surface obeyed Langmuir’s adsorption isotherm. The results obtained, i.e., corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudates and the synergistic effects of Acacia senegal gum exudates and halides from polarization and impedance measurements were in good agreement.
 Keywords: corrosion, inhibition, mild steel, synergistic effect, Acacia senegal, gum exudate

The Ameliorative Role of Acacia senegal Gum against the Oxidative Stress and Genotoxicity Induced by the Radiographic Contrast Medium (Ioxitalamate) in Albino Rats.

Arabic gum (Acacia senegal, AG) is proven effective antioxidant and cytoprotective agent. The present study was designed to test this notion by investigating the possible role of AG against the radiographic contrast medium (Ioxitalamate, Telebrix-35®, TBX)-induced oxidative stress and genotoxicity. Albino rats were divided into four groups and supplied with either; distilled water, daily 10% (w/v) AG, an intravenous dose of TBX (1600 mg I/kg b.wt) and co-administration of TBX and AG. Rats were sacrificed and blood samples were collected to assess the genotoxicity employing the peripheral blood leucocytes fluorescent double staining; namely the acridine orange/ethidium bromide (AO/EB) staining and alkaline comet assay. Further, chromosomal analyses were done in bone marrow cells. Serum urea and creatinine levels, in addition to malondialdehyde (MDA), nitric oxide (NO), catalase (CAT) and glutathione (GSH) levels in kidney tissues were measured. Liquid chromatography-mass spectrophotometry (LC-MS-MS) was performed to identify the chemical composition of AG extract. Kidney functions, single/double-stranded DNA damage, chromosomal aberrations, mitotic index, MDA and NO levels were significantly (p < 0.001) increased in TBX-treated group compared to the control and AG-treated one. Meanwhile, CAT and GSH activities were significantly diminished and the AG supplementation significantly (p < 0.001) ameliorated these effects compared with the control and AG-treated groups. Five compounds have been identified using GNPS networking including 7,3′,4′-Trihydroxyisoflavone, Noscapine, Tetrahydropapaveroline, Costunolide, Hesperidin. In conclusion, results of the present study suggest that AG exerted a protective role against TBX-induced oxidative stress and genotoxicity which may be attributed to the active metabolites in the gum.

Emulsifying properties of Acacia senegal gum: Impact of high molar mass protein-rich AGPs

The impact of high molar mass protein-rich arabinogalactan-proteins (AGPs) on emulsifying properties of Acacia senegal gums were studied using reconstituted gums obtained with two distinct fractions: one containing these specific high molar mass AGPs and the other protein-poor low molar mass AGPs. To produce and stabilize limonene emulsions, the experimental design emphasized not only the role of high molar mass protein-rich AGPs, but also the importance of high total concentration. At low protein contents, reconstituted gums required a slightly higher content in high molar mass protein-rich AGPs than original A. senegal gum, that confirmed the role of low molar mass protein-rich AGPs in the adsorption at interfaces. The comparison of the creaming index between original and reconstituted gums as well as the monitoring of instability phenomena by turbiscan up to 30 days clearly demonstrated the prevalent impact of the bulk apparent viscosity in the long-term stability of emulsions.

Nutritional and Structural Evaluation of Sweitenia Mycrophylla Exudate Gum: A Potential Excipient and Food Additive

Nutritional and structural analysis of S. mycrophylla were investigated using standard methods. Elemental analysis of the purified S. mycrophylla gum sample revealed the content of potassium, sodium, calcium, manganese, magnesium, iron and zinc to be 600.0 ± 1.52 mg/g, 300.23 ± 0.2 mg/g, 0.31 ± 0.00 mg/g, 410.33 ±1.0 mg/g, 149.6 ± 4.60, 8.7±0.00 mg/g and 61.1±0.22 mg/g respectively. Gum had high content of potassium, sodium, magnesium and zinc and lower concentration of calcium, manganese and iron. Proximate analysis shows moisture content to be 5.70 ± 0.15%, Ash content 2.80±0.05%, Protein content 1.43 ± 0.01%, crude fiber 4.30 ± 0.01%, and crude fat 1.50. ± 0.03%, and carbohydrate 85.98±1.10%. These results compared favorably with acacia senegal gum (gum arabic) and makes this exudate gum highly recommendable for use in food and pharmaceutical industries. NMR spectroscopy revealed that the gum is a galactomannan type polysaccharide with mannose/ galactose ratio of 2.60. Due to its good physicochemical properties and mannose/ galactose ratio, Sweitenia mycrophylla galactomannan could be a useful polysaccharide for food and pharmaceutical industry.

The colloidal stabilization of young red wine by Acacia senegal gum: The involvement of the protein backbone from the protein-rich arabinogalactan-proteins

The arabinogalactan-proteins (AGPs) from Acacia senegal gum are used as protective colloid in young red wines to prevent the precipitation of the coloring matter. Usually, Acacia senegal gum is chosen based on its efficiency to stabilize iron hexacyanoferrate salts in hydro-alcoholic solution. In this study, the protective activity of Acacia senegal gum and its macromolecular fractions (HIC–F1, HIC–F2 and HIC–F3), separated according to their hydrophobicity, towards the precipitation of iron hexacyanoferrate salts and polyphenols in hydro-alcoholic solutions are reported. AGPs prevent the colloidal instability of both iron hexacyanoferrate salts and polyphenols in “model” hydro-alcoholic solutions and young red wine with a good correlation between results obtained on both systems. This result strengthens the use of iron hexacyanoferrate salts (hydro-alcoholic – mineral test) for the evaluation of the protective activity of A. senegal gum in young red wine. The precipitation of iron hexacyanoferrate salts is avoided by the electrostatic binding of Ca2+, the driver of the instability, with the negatively charged carried by amino-acids from the protein backbone or both by amino acids and uronic acid monosaccharides localized close to the protein backbone of AGPs. The protective activity closely depends on the protein content of AGPs in both iron hexacyanoferrate salts and polyphenols hydro-alcoholic solutions: the more they are rich in proteins, the more their colloidal stabilizing efficiency is (HIC–F3>HIC–F2>HIC–F1). The differences observed in the protective activity between AGPs from the three HIC fractions are relied not only to their protein content but also to their related rate of glycosylation that modulates the protein accessibility to its environment, then their physicochemical properties as their hydrophobic behavior.

Recovery, structure and physicochemical properties of an aggregate-rich fraction from Acacia senegal gum

Acacia senegal gum (Asen) is a natural exudate of Acacia trees species largely used in food as well as other industries. This natural product appears as a continuum of molecular species which shows diverse sugar and protein composition, molar masses and charge density. The presence of larger macromolecules, or aggregates, has been demonstrated to have a great influence on the Acacia gum characteristics. The present work is designed to recover and characterize one protein-rich fraction presenting a high aggregate content. With this fraction we will open the door to future works with the aim to acquire a deeper knowledge about the origin and the role of the aggregates from Asen gum. Our methodology is based on the well-known ion exchange chromatography, using DEAE Sephacel gel as stationary phase. We have separated Asen into two different fractions (fraction IEC-F1 and fraction IEC-F2), being both of them confirmed as arabinogalactan-proteins (AGP) by Yariv detection. Fraction IEC-F1 has been thoroughly characterized (sugar and amino acid composition, molar mass distribution, weight-average molar mass, number-average molar mass, polydispersity index, intrinsic viscosity, radius of gyration, Mark-Houwink-Sakurada analysis, hydrodynamic radius, partial specific volume and partial specific adiabatic compressibility). From amino acid data, we have estimated that fraction IEC-F1 theoretically corresponds to about 70% of HICF3 and 30% of HICF2, respectively the second and the third fractions separated by hydrophobic interaction chromatography (HIC) and largely described in literature. The obtained information indicates that fraction IEC-F1 appears as a fraction highly rich in aggregates.

The Protective Effect of Acacia senegal gum against Gentamicin-Induced Nephrotoxicity In Albino Rats

Introduction: Acacia senegal gum is commonly known as Arabic gum or gum Arabic(GA) which obtained from the branches and stems of the trees as a dried gummy exudates. It is widely used in food and pharmaceutical industries as emulsifier and suspending agent. It has many pharmacologic effects including gastrointestinal effects such as increasing the short chain fatty acids and enhance water and electrolytes intestinal absorption but variable effects on lipid metabolism. In chronic renal failure patients, gum arabic reduces serum urea nitrogen. It is a potent superoxide scavenger so that it have a good protective activity against acetaminophen-induced hepatotoxicity and doxorubicin-induced cardiotoxicity in rats. The Aim of study: In the present study, we investigated the protective effect of Acacia senegal gum against gentamicin (GM)-induced nephrotoxicity in male albino rats. Materials and Method: The animals were divided into three groups A (Control), B (GM-only treated rats, 80mg/Kg, IM for 7days) and C (GA 10g/100ml water, orally for 4weeks prior to GM treatment). The nephrotoxicity was evaluated biochemically by determination level of serum Creatinine (Crea), Urea (Urea) and Uric acid (UA) level and histologically by microscopic examination the degree of proximal tubular damage. Results: The results showed significant increase in the level of Crea, Urea and UA in animals treated with GM only. In group (C), the level of Crea was high significant compared with the control but the level of Urea was significantly decreased compared with the control and the level of UA was significantly decreased compared with group B but higher than the control. Conclusion: These results suggest that Acacia senegal gum has some nephroprotective in rats, may be due to its antioxidant activities of GA.

Molecular characteristics, association and interfacial properties of gum Arabic harvested from both Acacia senegal and Acacia seyal

The molecular composition of Acacia senegal and Acacia seyal gum exudate samples were studied using transmission electron microscopy. The molecules observed in both samples were found to have diameters of either ∼20 μm, ∼60 μm or ∼10 μm. These most likely represent the arabinogalactan (AG), arabinogalactan-protein (AGP) and glycoprotein (GP) molecules present in Acacia gum exudates. Micrographs obtained for gum solutions that had been left to stand for up to 5 days, indicated that molecular aggregation had occurred, this was particularly evident for the Acacia senegal sample. This aggregation process was attributed to intermolecular electrostatic interactions. The adsorbed layer thickness of the gums adsorbed onto polystyrene latex particles was determined using dynamic light scattering. For the Acacia senegal gum sample, it was found that the adsorbed layer thickness increased over time and after 14 days had a value of 61 nm. These findings are indicative of multilayer adsorption, through intermolecular electrostatic interaction. For the Acacia seyal gum sample the adsorbed layer thickness was only ∼3 nm and did not increase over time. Transmission electron microscopy revealed the presence of a distinct, thick adsorbed layer for the Acacia senegal gum and the presence of a much thinner, more diffuse layer for the Acacia seyal gum sample. Emulsification studies showed that the Acacia senegal gum was more effective at stabilising limonene oil-in-water emulsions than the Acacia seyal sample and that this was because markedly more Acacia senegal gum adsorbed at the oil-water interface compared to the Acacia seyal gum exudate.

Functional Characteristics of Gum from &amp;lt;i&amp;gt;Acacia Nubica&amp;lt;/i&amp;gt;

The physicochemical of gum exudates from Acacia Nubica were analyzed and compared to those for Acacia Senegal gum. The molecular weight of Acacia Nubica and Acacia Senegal were determined using gel permeation chromatography (GPC) with on-line monitoring using light scattering, refractive index and UV absorbance detector, the result show that the three main component designated arabinogalactane protein (AGP), arabinogalactan (AG) and glycoprotein (GP) known to be present in Acacia Senegal could also be present in Acacia Nubica. However, in Acacia Nubica, the high molecular (AGP) component is less significant and present in less proportion than Acacia Senegal. The protein distribution in Acacia Nubica is different, and whereas the protein in Acacia Senegal is mainly associated with the high molecular weight component (AGP~106). It is distributed differently and mainly associated with a lower molecular weight component (AG) in Acacia Nubica. Emulsification studies of Acacia Nubica samples showed a poor emulsification performance and less stability than Acacia Senegal sample although it possessed large droplet size.

Fractionation and Physicochemical Studies of AcaciaSenegal Gums

Fractionation and Physicochemical Studies of AcaciaSenegal Gums

Physicochemical, shear flow behaviour and emulsifying properties of Acaciacochliacantha and Acaciafarnesiana gums

The physicochemical, shear flow behaviour and emulsifying properties of gum exudates from Acaciacochliacantha and Acaciafarnesiana were analysed and compared to those for Acaciasenegal gum. Evaluation of physicochemical properties showed that A. farnesiana and A. senegal gums displayed levorotatory activity, relatively high carbohydrate/protein ratio and high content of dietary fibre. Similarly, A. farnesiana and A. senegal gums formed stable oil-in-water emulsions with smaller droplet sizes and coalescence rates in the order of 10−8, meaning for very stable disperse systems. Otherwise, A. cochliacantha gum was the only with dextrorotatory activity, high content of protein and arabinogalactan-proteins (AGPs), but low carbohydrate fraction; nevertheless, despite the possible advantages of high protein content associated with emulsifying properties, this polysaccharide showed lesser stability on emulsions. These results indicate that there is correlation between emulsion stability and an adequate carbohydrate/protein balance in the gums; additionally of the AGPs presence. Thus, A. farnesiana gum may be considered for oil-in-water emulsion stabilization and sources of soluble dietary fibre due to their relatively high polysaccharide fraction.

Effect of grass density and date of tapping on Acacia senegal gum yield in north kordofan state, Sudan

We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels (100% and 50% grass cover in addition to bare and burnt). The second factor, date of tapping was tested in three levels namely (1st Oct, 15th Oct and 1st Nov). The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences (p < 0.01) of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings (1st–4th out of seven) in addition to total yield (kg/ha). With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly (p < 0.05) increased in only two pickings (third and fourth) in El Demokeya Forest Reserve and two pickings (1st and 2nd) at El Himaira Natural Forest. The density of grass cover significantly (p < 0.05) affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly (p < 0.05) increased at the early date of tapping.

Analytical Studies on the Gum Exudates from Anogeissus leiocarpus

Anogeissus leiocarpus gum samples were collected randomly as natural exudates from 3 different locations in Sudan, namely Abojebiha (season 1994-1995), Elfula and Rosaries (season 1996-1997). Physicochemical properties of gum samples (moisture, ash, nitrogen, protein, specific rotation, relative viscosity, refractive index, equivalent weight, pH, uranic acid, reducing sugar and tannin content). Results showed significant differences within each location in most parameters studied except in the refractive index values which was found to be constant in all samples (1.334). The effect of location on the properties of gum samples was also studied and the analysis of variance showed insignificant differences (p<0.05) in al l properties studied except in ash content and this may be due to the differences in the type of clay soil which found in the three different locations. The general characteristics of Anogeissus leiocarpus gum might be described as the mean value of all properties studied of all gum samples of the three different location as follows: 9.2% moisture, 3.4% ash, 0.72% nitrogen, 4.74% protein%, -35.5° specific rotation, 1.68 relative viscosity, 4.2 pH, 1.334 refractive index, 14.3% uranic acid, 0.44% reducing sugar 1336.0% equivalent weight and 0.68% tannin content. UV absorption spectra of gum samples were determined and the maximum absorption points were found the same ranging between wave length 243 and 285. Cationic composition of gum samples was also determined and the results showed that magnesium (Mg) has the highest value in all samples followed by iron (Fe), sodium (Na), potassium (K), calcium (Ca), zinc (Zn) and trace amount of manganese (Mn), copper (Cu), nickel (Ni), cadmium (Cd) and lead (Pb). Functionality (water holding capacity and emulsifying stability of Anogeissus leiocarpus gum were studied. The water holding capacity value was found to be 65.5% and emulsifying stability value was found to be 1.008 insignificant differences were observed between Anogeissus leiocarpus gum and Acacia senegal gum for the 2 parameters studied.