Hydrothermal synthesis of silver nanoparticles in Arabic gum aqueous solutions

Finely divided silver nanoparticles were synthesized via the hydrothermal method. Arabic gum （AG） was used as both the reductant and steric stabilizer without any other surfactant. By adjusting the reaction temperature, mass ratio of AG to AgNO3, and reaction time, silver nanoparticles with different morphological characteristics could be obtained. The products were characterized by UV-Vis, FTIR, TEM, SEM, and XRD measurements. It was found that temperature and AG played an important role in the synthesis of mono-disperse silver nanoparticles. Well dispersed and quasispherical silver nanoparticles were obtained under the optimal synthesis conditions of 10 mmol/L AgNO3, m（AG）/m（AgN03）= l：1, 160 ℃ and 3 h.

Microencapsulation of Lipase and Savinase Enzymes by Spray Drying Using Arabic Gum as Wall Material

Enzymes have been used in detergents over the years. They can improve the detergent’s efficiency due to their activities against hard stains. Nevertheless, enzymes cannot maintain their properties indefinitely, since they are exposed to stress factors, like temperature, pH, mechanical processes and others. Consequently, enzymes lose their structure and they are not functional. For this reason, microencapsulating these proteins is a feasible solution to improve their use in industrial processes and commercial products. Spray drying technology has been selected because a lot of scientific literature proved its useful application in a variety of industries. In particular, savinase and lipase are the two encapsulated enzymes in this work. Savinase attacks proteins and lipase removes fats, so they are suitable enzymes for detergent industry. Arabic gum has been used as wall material. Morphology, size and activity of the obtained microcapsules have been analyzed in order to find the best conditions to produce them. In conclusion, useful microcapsules of lipase and savinase can be obtained with the mentioned technology.

Enhancement of the Antigenotoxic and Antioxidant Actions of Eugenol from Spice Clove and the Stabilizer Gum Arabic on Colorectal Carcinogenesis

Spices are defined as any aromatic condiment of plant origin used to alter the flavor and aroma of foods. Besides flavor and aroma, many spices have antioxidant activity, mainly related to the presence in cloves of phenolic compounds, such as flavonoids, terpenoids and eugenol. In turn, the most common uses of gum arabic are in the form of powder for addition to soft drink syrups, cuisine and baked goods, specifically to stabilize the texture of products, increase the viscosity of liquids and promote the leavening of baked products (e.g., cakes). Both eugenol, extracted from cloves, and gum arabic, extracted from the hardened sap of two species of the Acacia tree, are dietary constituents routinely consumed virtually throughout the world. Both of them are also widely used medicinally to inhibit oxidative stress and genotoxicity. The prevention arm of the study included groups: Ia, IIa, IIIa, Iva, V, VI, VII, VIII. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the same period and for an additional 9 weeks, the animals received either water, 10% GA, EUG, or 10% GA + EUG by gavage. The treatment arm of the study included groups Ib, IIb, IIIb e IVb, IX, X, XI, XII). Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the subsequent 9 weeks, the animals received either water, 10% GA, EUG or 10% GA + EUG by gavage. The novelty of this study is the investigation of their use alone and together for the prevention and treatment of experimental colorectal carcinogenesis induced by dimethylhydrazine. Our results show that the combined use of 10% gum arabic and eugenol was effective, with antioxidant action in the colon, as well as reducing oxidative stress in all colon segments and preventing and treating genotoxicity in all colon segments. Furthermore, their joint administration reduced the number of aberrant crypts and the number of aberrant crypt foci (ACF) in the distal segment and entire colon, as well as the number of ACF with at least 5 crypts in the entire colon. Thus, our results also demonstrate the synergistic effects of 10% gum arabic together with eugenol (from cloves), with antioxidant, antigenotoxic and anticarcinogenic actions (prevention and treatment) at the doses and durations studied, in the colon of rats submitted to colorectal carcinogenesis induced by dimethylhydrazine.

Effect of Gum Arabic from Acacia senegal var. kerensis as an Improver on the Rheological Properties of Wheat Flour Dough

Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.

Physico-Chemical, and Sensory Properties of Mayonnaise Substitute Prepared from Chia Mucilage (Salvia hispanica L.) and Gum Arabic from Acacia senegal var. kerensis

Gum Arabic (GA) from Acacia senegal var. kerensis has been approved as an emulsifier, stabilizer, thickener, and encapsulator in food processing industry. Chia mucilage, on the other hand, has been approved to be used as a fat and egg yolk mimic. However, both chia mucilage and gum Arabic are underutilized locally in Kenya;thus, marginal reports have been published despite their potential to alter functional properties in food products. In this study, the potential use of chia mucilage and gum Arabic was evaluated in the development of an eggless fat-reduced mayonnaise (FRM). The mayonnaise substitute was prepared by replacing eggs and partially substituting sunflower oil with chia mucilage at 15%, 30%, 45%, and 60% levels and gum Arabic at 3% while reducing the oil levels to 15%, 30%, 45%, and 60%. The effect of different concentrations of oil and chia mucilage on the physicochemical properties, for example, pH, emulsion stability, moisture content, protein, carbohydrate, fats, calories, ash, and titratable acidity using AOAC methods and sensory properties for both consumer acceptability and quantitative descriptive analysis of mayonnaise were evaluated and compared to the control with eggs and 75% sunflower oil. The results indicated that all fat-reduced mayonnaises had significantly lower energy to 493 kcal/100g and 20% fat content but higher water content of 0.74 than the control with 784 Kcal/100g calories, 77% fat and 0.39 moisture. These differences increased with increasing substitution levels of chia mucilage, as impacted on pH, carbohydrate, and protein. There was no significant difference between ash content for both fat-reduced mayonnaise and control. Sensory evaluation demonstrated that mayonnaises substituted with chia seeds mucilage and gum Arabic were accepted. All the parameters are positively correlated to overall acceptability, with flavor having the strongest correlation of r = 0.78. Loadings from principal component analysis (PCA) of 16 sensory attributes of mayonnaise showed that approximately over 66% of the variations in sensory attributes were explained by the first six principal components. This study shows good potential for chia mucilage and gum Arabic to be used as fat and egg mimetics and stabilizers, respectively, in mayonnaise with functional properties.

Determination of optimum tapping date for gum arabic production in South Kordofan State, Sudan

Acacia senegal, the gum arabic producing tree, is the most important tree species for the livelihood of the people in South Kordofan State, Sudan. The objective of this study was to determine the optimum tapping date for gum arabic production in the study area. A randomized complete block design experiment with three replications was conducted at （Mead） area for two continuous growing seasons 2008/2009 - 2009/2010. The treatments comprised six tapping dates （1 Oct, 15 Oct, 1 Nov, 15 Nov, 1 Dec, and 15 Dec）. Results ishowed highly significant differences （p 〈 0.001） in gum arabic yield （g／tree） in all pickings and in the total gum yield between the tapping dates. The results also showed that tapping of trees on 15 October and 1 November gave a higher yield compared to the other dates. The highest gum yield of 1086.6 and 661.2 g/tree was recorded on 15 October and 15 November, while the lowest gum yield of 297.9 g/tree was recorded when the trees were tapped on 1 October. The two highest-yield dates of tapping （15 Oct and 1 Nov） are recommended as the best time for tapping for gum arabic production in South Kordofan State. These results can be used to increase gum arabic production and farmer income in South Kordofan State.

Growth performance and gum arabic production of Acacia senegal in northwest lowlands of Ethiopia

Despite the wide distribution of natural stands of Acacia senegal in Ethiopia, commercial exploitation of gum arabic is con- strained by lack of tapping and development techniques. We evaluated the gum arabic yield from natural stands of A. senegal and the growth of 6 provenances in different parts of the country. For the gum yield evalua- tion from natural stands, four tapping positions and three tapping seasons were tested in a factorial RCB design. The second experiment in Metema evaluated survival and growth of six provenances. A. senegal trees in natural stands respond well to tapping if tapped during the appropriate season and at the correct position on the tree. The mean gum yield did not vary significantly by tapping season （p=0.63）. Higher mean yield was, however, collected from trees tapped in October （96 g.tree^-1 per two harvests）. The mean yield differed significantly （p=0.009） between the tapping positions. Mean separation （ct=0.05） shows that trees tapped at mid stem gave higher yield （160 g.tree^-1 per two harvests）. The interac- tion effect of tapping season and position was not significant. Higher mean yield （（70 ± 112） g.tree^-1） was recorded in mid October-mid stem in two harvests. The second experiment indicated statistically significant difference in mean survival （p=0.0298）, height （p=0.000） and root col- lar diameter （RCD）, （p=0.012） between the six provenances. Highest survival, height and root collar diameter growth was observed from Ab- derail provenance （100%, （148±11） era, （38±11） mm, respectively）. We recommend October and mid-stem and branches as appropriate tapping season and position. We recommend planting of the Abderafi provenance for the study area due to its superior growth and survival. Our study contributes to the proper selection of provenances for plantation devel- opment and improved tapping technology for better production of gum arabic in the country.

Preparation and Quality Evaluation of Extended Beef Rounds Containing Gum Arabic from Acacia senegal var. kerensis

It was of interest to determine the water holding effect of the gum from the Acacia senegal var. kerensis in extended beef rounds. Beef rounds injected at two injection levels (30% and 35% over green weight) with curing brines containing gum arabic at 1%, 1.5%, 2.0%, 2.5% and 3.0% of the final product were investigated. A non-injected sample and a product injected with soy protein concentrate (SPC) at 3.5% of the final product weight were prepared for comparison. Mean results indicated that the level of gum arabic from Acacia senegal var. kerensis used in curing brines significantly increased the cook yield and reduced the extractable moisture in cooked extended beef rounds. The injection of beef with curing brine also significantly increased the cook yield and the extractable moisture of the extended beef rounds as compared to the non-injected beef samples. Both injection and gum levels had a significant effect on the proximate composition and sensory properties of the resulting beef rounds. Sensory analysis revealed that samples containing gum arabic at 2.5% were juicier and comparable to those containing SPC at 3.5% injection level. Furthermore, these samples had the highest overall preference comparable to samples injected with curing brines containing SPC. This is the first report on the physicochemical properties of extended beef rounds containing gum arabic from Acacia senegal var. kerensis.

Physicochemical Properties of Gum Arabic

Gum Arabic is harvested commercially from wild trees throughout the Sahel from Senegal and Sudan to Somalia and in the northern part of Nigeria.Clumps of gum Arabic were collected and dirt particles were removed,the samples were dried and grounded to fine powder.The Physicochemical properties of gum Arabic was determined using standard methods and the values obtained showed;Moisture content 6.9%±5,Soluble content 90.6%,Viscosity 5.45±3Ns/m2,Ash content 3.2±4%,Zinc 3mg/kg,Iron 41mg/kg±5,Manganese 48.2mg/kg±5 and Copper 33.3mg/kg±2.The gum also contains carbohydrate 0.3ppm±2,protein 0.75ppm±2,starch 0.0076±10 and nitrogen 0.12ppm±5.It was observed that the gum does not contain cadmium and nickel.

Effect of Gum Arabic as Partial Replacement of Cement on the Durability Properties of Compressed Laterite Blocks

Compressed stabilized earth blocks are the innovation of building materials replacing the earth blocks commonly called adobe. Common stabilizers (cement and lime) have been found to be expensive and harmful to the environment. Finding a natural, available, environmentally friendly stabilizer is vital. The objective of this study was therefore to assess the effects of gum Arabic (GA) as binder on the durability properties of laterite blocks. Compressed laterite blocks were stabilized with 2% and 6% respectively as total percentage of binders in the blocks (cement and/or GA). The results showed that GA improved the abrasion and drop resistances of compressed blocks. It has been found that the abrasion resistance of compressed blocks increased with the increase of GA content and the decrease of cement content. For instance, the mass abraded away of blocks stabilized with cement only was reduced up to 95.18% when GA was used to partially replace cement. As for drop test, the higher the content of GA the higher the resistance of blocks to drop.

Curcumin gum Arabic nanoparticles demonstrate potent antioxidant and cytotoxic properties in human cancer cells

The main purpose of the study was to enhance the stability and therapeutic effects of Curcumin(Cur)through nanoformulation with gum Arabic(GA)as a coating agent through an efficient synthetic approach.The antioxidant properties of the developed nanoparticles(Cur/GANPs)were assessed through several in vitro assays,such asβ-carotene bleaching activity,DPPH,and nitric oxide scavenging activities in addition to evaluating its inhibitory activity on angiotensinconverting enzyme(ACE).The cytotoxicity of Cur/GANPs was evaluated in vitro using different types of human cancer cells including breast cancer(MCF7,MDA-MB231),liver cancer(HepG2),and colon cancer(HT29)cells.The prepared particles displayed an elliptical shape with a size ranging between 20–260 nm and a potential difference of–15 mV.The Cur/GANPs exhibited significant antioxidant activity compared to free curcumin when using concentrations between 31.5 and 500μg/mL.The Cur/GANPs also had inhibited the growth of all cancer cell lines in a proportional trend with concentrations used.Hence,the encapsulation with gum Arabic has augmented the antioxidant and anti-neoplastic effects of Curcumin.Therefore,Cur/GANPs may have effective therapeutic properties in diseases attributed to oxidative stress like cancer and hypertension.

Influence of Gum Arabic from <i>Acacia Senegal</i>var. <i>kerensis</i>on the Modifications of Pasting and Textural Properties of Cassava and Corn Starches

The use of hydrocolloids to modify the properties of native starches has been on the rise in the recent times due to the market demand for natural, safe and economical food ingredients. The objective of this study was to investigate the effect of gum Arabic from Acacia senegal var. kerensis to modify pasting and textural properties of corn and cassava starches, as an alternative to chemical and enzymatic modification. Blends were prepared by substituting the starches with gum at different levels (0%, 0.5%, 2.0%, 4.0%, 6.0% and 8.0%), whereas native corn and cassava starches were used as control. The pasting properties of the starch-gum mixed systems were determined using the Brabender viscograph while the textural properties (firmness, consistency, cohesiveness and work of cohesion) were determined using Texture Analyzer. Results showed that the gum Arabic significantly decreased all the viscosity parameters (peak viscosity, final viscosity, break down and setback values) of both starches at all levels of substitution. However, there was no significant effect of gum Arabic on the pasting temperature (72.05°C - 71.85°C) for corn starch and (68.90°C - 68.65°C) for cassava starch. The degree of gel firmness and consistency was higher in corn starch than in cassava starch and the effect of gum addition differed with each starch. The findings from this study indicate that gum Arabic significantly modified the pasting and textural properties of corn and cassava starches due to strong interaction between the gum and the starches. Hence, this property of gum Arabic could be useful in controlling starch retrogradation and determining starch end use functionality.

Benefits of Gum Arabic, for a Solitary Kidney Under Adverse Conditions:A Case Study

Gum Arabic(GA,called E-414 in the EU food industry),a natural biopolymer resin is a dried exudation obtained from the stems and branches of natural strains of Acacia Senegal(L)Willdenow.It consists mainly of high molecular weight polysaccharides and their calcium,potassium,and magnesium,which on hydrolysis yield arabinose,galactose,rhamnose,and glucuronic acid.Fermentable natural fiber of gum Arabic act as probiotics improves the absorption of minerals,especially calcium and helps to maintain a healthy balance of bacteria in the gastrointestinal(GI)tract.Extraction,transformation,or reprocessing of nitrogenous wastes(ammonia,urea,and uric acid)by the GI tract is a potentially low-cost means of switching for missing renal function.Binding of nitrogen compounds to be inert orally by administration of gum Arabic is the safe solution either in normal renal function or renal failures.In this study,clinically,we observed a case of solitary kidney under adverse condition long‑term treating with gum Arabic the vast potential of bioactive phytochemicals as a nontoxic,efficient with uric acid and bilirubin lowering agent and anti‑inflammatory effects,considering the gum Arabic as a potential therapeutic supplement,beneficial in chronic renal failure,cardiovascular disease,pain management,and dental health.Despite the nonexistent background concerning the benefits of gum Arabic,for a solitary kidney under adverse conditions,our study has confirmed that long‑term consumption of gum Arabic not only has no side effect but also protects multi-organs damage from drug adverse reactions and consequences of baseline disease,including renal,vascular,dental and inflammatory diseases.

Determination of Gum Arabic (<i>Acacia nilotica</i>) Constituents Using Laser Induced Breakdown Spectroscopy

In this work, Laser Induced Breakdown Spectroscopy (LIBS) was used to determine the constituent of Gum Arabic (Acacia nilotica) collected from five different locations in Sudan. Gum samples were irradiated with 80 mJ pulse energy of Nd-YAG laser (1064 nm) and Atomic spectra Database was used for the spectral analysis of the plasma emitted from these samples. It was found that the samples contain the elements C, O, H, S, N, P, Na, Mg, Ca, Fe, Cr, Mn, Co with different amounts. Some elements like (Ti, Br, Ar, Th, Kr, Sc and Pr) are recorded here for the first time.

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.

Preparation of ultrafine silver powders with controllable size and morphology

The ultrafine silver powders were prepared by liquid reduction method using Arabic gum as dispersant.The effects of different dispersants,pH values,and temperature on the morphology and particle size of silver powders were investigated.It is found that Arabic gum can better adsorb on silver particles via chemical adsorption,and it shows the best dispersive effect among all the selected dispersants.The particle size of silver powders can be finely tuned from 0.34 to 4.09μm by adjusting pH values,while the morphology of silver powders can be tuned by changing the temperature.The silver powders with high tap density higher than 4.0 g/cm3 were successfully prepared in a wide temperature range of 21.8-70°C.Especially,the tap density is higher than 5.0 g/cm3 when the temperature is optimized to be 50°C.The facile process and high silver concentration of this method make it a promising way to prepare high quality silver powders for electronic paste.

Computational and experimental study on corrosion inhibition potential of the synergistic 1:1 combination of Arabic and cashew gums on mild steel

The synergistic study of Acacia Senegal (arabic gum) and Anacardium occidentale (cashew gum) combination in corrosion inhibition of mild steel was carried out to determine the inhibition efficiency of their combination. The gums were purified using standard methods and the blend prepared using the method as described by Femi – Oyewo et al. The blend was then used for corrosion study at two temperatures (303 K and 333 K) and the corrosion rates calculated. The adsorption process was found to satisfy the Langmuir isotherm and hence the sorption study reveals that the interaction is a physical one since the free energy of adsorption (ΔG^(o) ads kJ/mol) is given as (−16.47 and −15.61) kJ/mol at temperature T = 303 K and 333K accordingly. The GCMS technique was used to characterize the blend, five chemical compounds and their area percentage [6-O-(1-L-maloyl)-alpha-,beta-D-Glcp (veracylglucan A) (22.11%), 6-Octadecanoic acid (55.76%), Methylhexadecanoate (3.97%), 1-Pentadecane carboxylic acid (10.78%) and 9, 12-Octadecadienoic acid (7.38%)] were identified and subjected to computation corrosion study, the binding energy for the constituents of the blend on Fe surface were computed using Accelrys Material Studio and the mean values were found to be −327.097 kJ/mol, −446.943 kJ/mol, −602.826 kJ/mol, −608.625 kJ/mol and −693.749 kJ/mol respectively.

Comparative study of the characterisation and extraction techniques of polyphenolic compounds from Acacia seyal gum

Background Acacia seyal gum(ASG)is an abundant source of natural polyphenolic compounds(NPPCs)and antioxidant activity with numerous benefits and is often used in cancer treatment.The type of extraction technique can significantly impact the yield and isolation of NPPCs from ASG.The traditional use of maceration extraction reportedly yields fewer NPPCs.Objectives This study investigated five extraction techniques for NPPCs and ASG antioxidant activity,namely:homogenisation,shaking,ultrasonication,magneticstirring,andmaceration.Materials and methods The evaluation of the antioxidant activity(AoA)of the extracted NPPCs from ASG used five assays,namely:total flavonoids content,Folin-Ciocalteu index,2,2-diphenyl-1-picrylhydrazyl radical scavenging activity,ferric reducing antioxidant power,and cupric reducingantioxidantcapacity.Results To minimise the data set dimensionality requires principal component analysis.The ultrasonic and maceration techniques were the best techniques to extract NPPCs and examine the AoA of ASG,with a high correlation between the NPPCs and AoA.However,the maceration process was slow(12 h)compared to ultrasonication(1 h).Slow extraction can result in a decline of the NPPCs due to polyphenol oxidase-enzyme and impact productivity.Conclusions These findings provide an essential guide for the choice of extraction techniques for the effective extraction of NPPCs from ASG and other plant materials.

Protective effects of two food hydrocolloids on dental erosion:Nanomechanical properties and microtribological behavior study

In this study,the protective effects of two food hydrocolloids,Xanthan gum and Arabic gum,on dental erosion are investigated from the perspective of the nanomechanical properties and microtribological behavior of acid-eroded enamel.Enamel specimens prepared from extracted human teeth were immersed in citric acid solution(CAS),CAS with 0.03%w/v Xanthan gum and CAS with 0.03%w/v Arabic gum,respectively,for 10 min to obtain three groups of eroded specimens.The nanomechanical properties and microtribological behavior of enamel were examined using nano-indentation/scratch techniques.The results show that compared with Arabic gum,Xanthan gum inhibits enamel surface demineralization and acid permeation more effectively because of a more uniform and denser adsorption on the surface of the enamel.The impairment of the nanomechanical and microtribological properties of the enamel surface by acid erosion is mitigated more significantly by adding trace amounts of Xanthan gum than Arabic gum.In summary,adding trace food hydrocolloids reduces enamel surface demineralization and inhibits acid permeation to mitigate the influence of erosion on the mechanical and tribological properties of enamel.The adsorption state of food hydrocolloids is the determining factor in the permeability of acid agents into the enamel and plays a significant role in preventing dental erosion.