Gum Arabic Samples Research Articles

Characterization of Marigold Flower (Tagetes erecta) Extracts and Microcapsules: Ultrasound-Assisted Extraction and Subsequent Microencapsulation by Spray Drying.

Ultrasound-assisted extraction using response surface methodology was employed to extract marigold flower, resulting in a marigold flower extract (MFE) with elevated levels of total phenolic compounds (TPCs), total flavonoid content (TFC), total carotenoid content (TCC), and antioxidant activity, as assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays, under conditions of 40 °C temperature, 15 min extraction time, and 68% ethanol concentration. The MFE was subsequently encapsulated using spray drying with 45% maltodextrin (MD) (MFE-MD; 1:1, 1:2) and 20% gum arabic (GA) (MFE-GA; 1:2, 1:3). The MD (1:2 ratio) sample showed the highest encapsulation yield, while the 45% MD (1:1 ratio) sample exhibited the highest encapsulation efficiency (p ≤ 0.05). Samples containing 45% MD (1:1 ratio) and 20% GA (1:2 ratio) had the highest moisture content, with the 45% MD (1:1 ratio) sample showing the lowest water activity (p > 0.05). These samples also displayed higher L* and a* values compared to the 20% GA samples, which had increased b* values (p ≤ 0.05). Micrographs of the 20% GA (1:3 ratio) and 45% MD (1:2 ratio) samples revealed spherical shapes with smooth surfaces. The 20% GA (1:2 ratio) microcapsules exhibited the highest total phenolic content (TPC) among the samples (p ≤ 0.05). Thus, ultrasound-enhanced extraction combined with response surface methodology proved effective in producing functional food ingredients from plants.

Rheological, Thermal, Structural, and Chemical Changes during Oxidation of Gum Arabic by Ozone

ABSTRACT Gum Arabic (GA) samples with 6% (w/v) concentration in water were ozonated for 5, 30, and 60 min, corresponding to 0.0030, 0.0125, and 0.0140 g consumed ozone/L, respectively. Ozonation steadily reduced the viscosity, flow, and consistency index of GA suspensions significantly (P < 0.05). Although no apparent changes were observed in the general chemical structure of GA samples, an increase in the absorbance of -OH bends was detected by FTIR analysis. DSC peak temperatures (292.0 ± 0.1 to 281.0 ± 0.9 °C) and pH values of samples (4.84 ± 0.13 to 2.90 ± 0.09) were decreased upon ozonation. Small but statistically significant differences (P < 0.05) were obtained for water solubility and water absorption index of samples after ozonation. Phenolic compounds and radical scavenging activities in GA were increased significantly (P < 0.05) by ozonation. Ozonation, which is an environmental-friendly unit operation, would offer valuable contributions to relevant industries with improved properties of GA.

The Effect of Gum Arabic in Treatment of Kidney Dysfunction in Chickens

Gum arabic is a polysaccharides obtained from the stems and branches of Acacia senegaltree. In folk medicine Gum arabic has been reported to have anti-oxidant and nephroprotectant effects. This study aimed to evaluate the Gum arabic effect on kidney dysfunction in chickens which induced by cadmium nitrate. Healthy chickens were divided into three groups, 5 chickens in each group; group 1: Normal group fed on basal diet, group 2: Control group feed on basal diet mixed with (100 ml/kg b. w.) cadmium nitrate, Group 3: Treated group, chickens feed on basal diet mixed with cadmium nitrate (100 ml/kg b. w.) then treated with Gum Arabic extract (500 g/kg body weight). . Blood samples were collected at the beginning of the experiment (group 1: normal), after 5 days blood samples collected from (group 2: control) and after 10 days of Gum Arabic treatment blood samples collected from (group 3: treated), creatinine and uric acid were estimated as a kidney function parameters. The results demonstrated that oral administration of cadmium nitrate (control group) recorded a significant increase at (p Furthermore, the results obtained from this study suggested that oral administration of Gum Arabic extract may be helpful in the prevention of kidney dysfunction and may represent an effective therapy that normalizes serum creatinine and serum uric acid levels in chickens.

Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures

Freeze-drying is an energy intensive unit operation used for the production of dehydrated foods, such as instant coffee and dried fruits, and results in high sensorial, nutritional and reconstitution properties of the final products. Understanding the relationships between operating conditions and product quality is essential to design processes that are energy efficient, whilst producing high quality dried foods.In this work, the properties (microstructure and reconstitution) of freeze-dried gum arabic samples (with initial concentrations ranging between 20 and 60% solids by weight) were evaluated. The materials were dried at three different primary drying shelf temperatures, Ts (−20, −30 and −40 °C).Sample temperatures recorded throughout freeze-drying were close to the pre-set Ts, with the exception of the 60% initial concentration system, where the sample was hotter than the shelf by 10–15 °C, in particular on increasing Ts. This was attributed to a combination of local temperature and pressure conditions that may have resulted in partial melting of the material. For the 20–50% systems, the properties of the freeze-dried materials were mainly affected by the initial concentration of the system, with increasing initial concentration generally resulting in lower porosities (ranging between 20 and 40%) and higher reconstitution times (ranging between 0.5 and 10min for 95% reconstitution). Pores were generally needle-shaped and <200 μm. Large (200–1800 μm), circular pores were observed in high initial concentration systems, and they were dominant in the microstructure of the freeze-dried 60% sample. The presence of these large bubbles was linked to the partial melting of the material, which enabled its expansion and puffing. For the 60% system, primary drying temperature had a profound effect on the properties of the freeze-dried solid, with samples dried at higher temperature showing higher porosity (e.g. 60–70% for Ts=−20°C) and faster reconstitution rates (e.g. 3min for 95% reconstitution at Ts=−20°C).Overall, this study demonstrates the significance of formulation and shelf temperature on the porous structure of freeze-dried samples, which directly influences product performance.

Reaction of gum arabic samples with monoclonal antibodies directed to plant cell wall polymers in dot immunobinding

Certain plant cell wall constituents have been found in gum samples derived from Acacia trees, thus analytical techniques for the determination of these plant cell wall components in any media can be applied in the analysis of the physico-chemical properties of these gums. In this experiment, gum samples harvested from various Acacia trees grown in different African countries were subjected to a dot immunobinding reaction using a panel of anti-plant cell wall directed monoclonal antibodies since the gum samples have been found to contain certain plant cell wall constituents. Five antiplant cell wall monoclonal antibodies, JIM 5, JIM 7, JIM 13, LM 6 and MAC 207 were reacted with fifteen gum Arabic samples 1 – 15 and water as control. The results showed that apart from reacting with the monoclonal antibodies, gum samples showed varying degrees of reactivity with the monoclonal antibodies. JIM 5 indicated no reaction with any of the gum samples, whereas JIM 7, JIM 13, LM 6 and MAC 207 exhibited reactions with the samples. The results suggest that, anti-plant cell wall directed monoclonal antibodies can be used as a tool to distinguish between gum Arabic samples from different tree species, as well as from different African countries. Thus, a testing kit which is easy to use and cheaper to acquire can be developed using anti-plant cell wall monoclonal antibodies, to improve quality control in the current gum trade.

Effect of arabinogalactan protein complex content on emulsification performance of gum arabic

The emulsification properties of the standard (STD), matured (EM2 and EM10) and fractionated gum arabic samples via phase separation induced molecular fractionation were investigated to find out how the content of arabinogalactan protein (AGP) complex affects the resulting emulsion properties. Phase separation and the accompanying molecular fractionation were induced by mixing with different hydrocolloids including hyaluronan (HA), carboxymethyl cellulose (CMC), and maltodextrin (MD). Increase of AGP content from 11 to 28% resulted in the formation of emulsions with relatively smaller droplet sizes and better stability. Further increase in the AGP content to 41% resulted in the formation of emulsions with larger droplets. In spite of the larger droplets sizes, these emulsions were extremely stable. In addition, the emulsions prepared with GA higher AGP content better stability in the presence of ethanol. The results indicate that AGP content plays a vital role in emulsion stability and droplet size.

Complex coacervates formation between gelatin and gum Arabic with different arabinogalactan protein fraction content and their characterization

This work aimed to investigate the possible impact of the chemical composition of gum arabic (GA) on the interactions and complexation mechanism with gelatin (G). For this purpose, two gum arabic samples were selected differing in the content of their arabinogalactan protein fraction (AGP), i.e. low (7%, GA7) and high (14%, GA14). The complex coacervates formation process was studied as a function of pH (from 7 to 2.4) and G:GA mixing ratio (1:2, 1:1, 2:1, 4:1, 6:1 w/w) by following changes in turbidity, ζ-potential and absorption of methylene blue – biopolymers mixtures. The complexation between the biopolymers (G-GA7 and G-GA14) was found to be stronger at a ratio of 1:1 and pH 3.7, where the highest yield (∼71%) was observed. The formed coacervates were examined using laser diffraction technique and optical microscopy along with Scanning Electron Microscopy, Fourier Transform Infrared analysis and Differential Scanning Calorimetry. Although both G:GA systems exhibited a similar behavior, some differences were observed. More specifically, results revealed that GA14 affected the surface charge characteristics of the G-GA complexes to a greater extent than GA7, while the corresponding liquid coacervates were more spherical, with a smoother surface and not aggregated. Additionally, G-GA14 complex coacervates were characterized by a more uniform morphology and size distribution along with a higher thermal stability implying thus a greater effectiveness of this system for the encapsulation of heat-sensitive materials.

Botanical and commercial characterisation of gum arabic and its detection in wine using non-targeted high resolution mass spectrometry

Gum arabic (GA) is the oldest and best known of all natural gums. Thanks to the particular characteristics resulting from its complex mixture of polysaccharides and glycoproteins, its field of application is extensive. In the oenological sector, it is used to prevent colour depigmentation and protein precipitation and although there is no declared limit, the International Code of Oenological Practices suggests not exceeding a dosage of 300 mg L−1.In this study, the botanical origin (Acacia senegal vs A. seyal) and commercial description (Kordofan region vs other Sub-Saharan areas, based on the traditional geographic provenance) were defined studying 44 GA samples with a non-targeted screening approach using high resolution mass spectrometry. From an initial group of 88 identified masses, 15 were selected to create a bi-factor PLS-DA statistical model able to correctly reclassify samples with 94.4% accuracy. Moreover, the study addressed the question of identifying gum addition in wines, analysing 98 untreated wines and comparing them with 40 wines to which gum arabic had been added (200 mg L−1). Considering the database of 88 masses, 4 of them were established to be markers of gum arabic addition (m/z 152.1067, 166.1225, 585.1428 and 643.1403). Principal component analysis performed with the signal (area) of the 4 masses highlighted three groupings differentiating untreated wines, wines treated with A. senegal gum and wines treated with A. seyal gum. m/z 152.1067 was tentatively identified as N-methyltyramine, while m/z 166.1225 as N,O-dimethyltyramine.

Use of guar gum, gum arabic, pectin, beta-glucan and inulin for microencapsulation of anthocyanins from chokeberry.

The aim of this study was to use micro-encapsulation technology to create microcapsules containing anthocyanins from chokeberry with guar gum, gum arabic, pectin, β-glucan and inulin as wall material. Aqueous extracts from chokeberry fruit were enclosed and spray dried using maltodextrin as a coating material with the addition of guar gum, gum arabic, pectin, beta-glucan, and inulin respectively. Physical properties of microcapsules were tested. The preparations also determined the total content of anthocyanins and vitamin C on the day of preparation and after 7 days of storage. In the executed research, the highest moisture content for gum arabic capsules was observed. The most different parameters of color were observed for capsules with beta-glucan. The biggest particles were observed for gum arabic and the smallest for guar gum. The differences were also noticed in chemical assays. The highest content of anthocyanins on the day of drying and after 7 days of storage was noticed for beta-glucan samples whereas the lowest content was observed for gum arabic samples. In case of vitamin C content, the sample, which stood out particularly, was pectin sample. The main conclusion is that the micro-encapsulation is an effective method to maintain the stability of sensitive compounds such as anthocyanins, but also ascorbic acid.

Effects of temperature and solvent condition on phase separation induced molecular fractionation of gum arabic/hyaluronan aqueous mixtures

Effects of temperature and solvent condition on phase separation-induced molecular fractionation of gum arabic/hyaluronan (GA/HA) mixed solutions were investigated. Two gum arabic samples (EM10 and STD) with different molecular weights and polydispersity indices were used. Phase diagrams, including cloud and binodal curves, were established by visual observation and GPC-RI methods. The molecular parameters of control and fractionated GA, from upper and bottom phases, were measured by GPC-MALLS. Fractionation of GA increased the content of arabinogalactan-protein complex (AGP) from ca. 11% to 18% in STD/HA system and 28% to 55% in EM10/HA system. The phase separation-induced molecular fractionation was further studied as a function of temperature and solvent condition (varying ionic strength and ethanol content). Increasing salt concentration (from 0.5 to 5 mol/L) greatly reduced the extent of phase separation-induced fractionation. This effect may be ascribed to changes in the degree of ionization and shielding of the acid groups. Increasing temperature (from 4 °C to 80 °C) also exerted a significant influence on phase separation-induced fractionation. The best temperature for GA/HA mixture system was 40 °C while higher temperature negatively affected the fractionation due to denaturation and possibly degradation in mixed solutions. Increasing the ethanol content up to 30% showed almost no effect on the phase separation induced fractionation.

Effect of polymer coating composition on the aggregation rates of Ag nanoparticles in NaCl solutions and seawaters

The aggregation behaviour of polymer-coated silver nanoparticles (AgNPs) was characterized in NaCl solutions, and in two seawaters of different salinities and dissolved organic matter (DOM) contents. Representative organic coatings i.e. tannic acid (TA), alginic acid (ALG), two gum Arabic samples (GAL and GAH), branched polyethylenimine (BPEI), and non-ionic surfactants (reference material NM-300K) were selected to cover a wide range of zeta-potentials. The stability in NaCl solutions, as determined from the rate of variation in hydrodynamic size within a timeframe of one hour, followed the order BPEI≫NM-300K≈GAL≫ALG≈TA≫GAH. In the seawater samples the order was NM-300K≈GAL≫ALG>GAH>TA≈BPEI, and only TA, GAL and NM-300K batches behaved as expected from the NaCl experiments. Remarkably, the BPEI sample showed the largest aggregation rate in the seawater sample with the highest DOM concentration (277μM C). The GAH sample displayed a non-monotonic variation in aggregation rate with NaCl concentration, apparently due to concomitant precipitation of AgCl. The results indicate that non-electrostatic stabilization mechanisms and DOM-coating interactions are important for the prediction of stability and persistence of polymer-coated AgNPs in seawater.

Determination of antioxidant activity of gum arabic: An exudation from two different locations

Gum Arabic (GA) is the main product of acacia trees. As a raw and commercial samples, GA was extracted with methanol and analysed to measure the antioxidant activity using five methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu indexes (FCI), which indicate total phenolic compounds (TPC), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC). This study used antioxidant assays to detect TPC and selected appropriate and inexpensive methods to determine the antioxidant capacity of GA samples. The results reveal that the FCI, ORAC, and CUPRAC are correlated highly with FRAP. Person’s correlation coefficient (r) values are 0.98, 0.93, and 0.99, respectively, based on the sample size of(n=8). This means that the TPC of GA is highly correlated with their antioxidant activities that are measured by these three methods. Hence the FCI, ORAC, and the CUPRAC methods are more effective and simpler. They had similar predictive power to the FRAP of GA antioxidant activity. Consequently, GA is generally recognized as being slightly acidic which may have been obtained from appropriate methods of the antioxidant capacity detection. This acidity is due to the electronic transfer mechanism based on the selection of the working pH.

Matrix Assisted Laser Desorption Ionization Mass Fingerprinting for Identification of Acacia Gum in Microsamples from Works of Art.

This paper reports an improved method for the identification of Acacia gum in cultural heritage samples using matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) after enzymatic digestion of the polysaccharide component. The analytical strategy was optimized using a reference Acacia gum (gum arabic, sp. A. senegal) and provided an unambiguous MS profile of the gum, characterized by specific and recognized oligosaccharides, from as little as 0.1 μg of material. The enhanced experimental approach with reduced detection limit was successfully applied to the analysis of naturally aged (∼80 year) gum arabic samples, pure and mixed with lead white pigment, and allowed the detection of gum arabic in samples from a late painting (1949/1954) by Georges Braque in the collection of the Art Institute of Chicago. This first application of the technique to characterize microsamples from a painting, in conjunction with analyses by gas chromatography/mass spectrometry (GC/MS), provided important insights into Braque's unusual mixed paint media that are also helpful to inform appropriate conservation treatments for his works. The robustness of the analytical strategy due to the reproducibility of the gum MS profile, even in the presence of other organic and inorganic components, together with the minimal sample size required, demonstrate the value of this new MALDI-TOF MS method as an analytical tool for the identification of gum arabic in microsamples from museum artifacts.

Comparative evaluation of gum arabic coating and vacuum packaging on chilled storage characteristics of Indian mackerel (Rastrelliger kanagurta)

The effect of edible coating using gum arabic on biochemical, microbiological, textural and sensory characteristics of fresh gutted mackerel stored at 4°C was investigated. The results were further compared against the samples packed under vacuum (VP) and conventional polyethylene pouches (CP). Coating with gum arabic (GC) markedly retarded lipid oxidation process in gutted mackerel compared to VP and CP samples. Moreover, VP and CP samples showed higher degree of textural deterioration compared to GC samples. Microbiologically, the shelf life of chilled gutted Indian mackerel was estimated to be 7-8, 17 and 19-20days for CP, GC and VP samples, respectively. The sensory analysis scores confirmed the efficacy of gum coating in retarding the spoilage process during chilled storage. The current study identifies the potential of edible coating with gum arabic to improve the overall quality of Indian mackerel and extend its storage life during chilled storage.

Gum Arabic-stabilized conjugated linoleic acid emulsions: Emulsion properties in relation to interfacial adsorption behaviors

Conjugated linoleic acid (CLA) is a dietary supplement due to its multiple health benefits. However, significant loss of biologically active CLA could occur due to oxidation. Oil-in-water emulsion is supposed to be an effective protection system. In a previous study (Yao et al., 2013), physical and chemical stabilities of CLA emulsion stabilized with gum Arabic were investigated, and the optimal gum concentration was identified as 5 wt%. The present study dealt with the interfacial adsorption of three gum Arabic samples (one conventional gum, GA; two matured gums, EM2 and EM10) at the CLA-water interface, in relation to their emulsifying properties. With increasing gum Arabic concentration, particle size (D[3,2]) of CLA emulsion decreased and slowly leveled off, which was accompanied with a gradual saturation of gum Arabic adsorbed at the emulsion interface. Nevertheless, surface load of gum Arabic at the emulsion interface (Γ, mg/m2) reached maximum at a gum concentration of 5 wt%. This could reasonably explain the optimal emulsion stability observed at this gum concentration, as revealed by particle size distribution of fresh emulsions and by acceleration test at 60 °C. Among the three gums, EM10 exhibited the highest emulsifying activity and conferred the best emulsion stability, despite of its lowest surface load. This is presumably due to a larger tendency of the AGP fraction in EM10 toward aggregation at the CLA-water interface.

Evaluation of hemicellulose as a coating material with gum arabic for food microencapsulation

In this study, hemicellulose-based coatings were assessed for use in microencapsulated fish oil. The fish oil emulsions were prepared using the solutions of gum arabic (GA), gum arabic-hemicellulose (GA-HC) and hemicellulose (HC) as the coating materials, amended with maltodextrin as a cheap filler material. The fish oil was then encapsulated with these emulsions using the spray drying method. The effects of the hemicelluloses on the emulsions and the formed microcapsules were evaluated by physical and chemical tests. Although the GA-HC and HC emulsions showed higher creaming index and apparent viscosity values than that of the GA samples, all emulsions showed shear-thinning behavior. The oil particle size of the emulsions was found to be affected by the apparent viscosity. The HC emulsions contained oil particles with the largest size among all samples (p<0.05). On the other hand, oil particle sizes of the reconstituted microcapsules were not significantly different (p>0.05). Scanning electron microscope (SEM) was also used to visualize the morphological characteristics of all microcapsules. The hemicellulose microcapsules (GA-HC and HC) had fewer dents than the GA microcapsules. The microencapsulating efficiency (MEE) of the GA microcapsules was found higher than that of the GA-HC and HC microcapsules. The HC microcapsules had the lowest water activity (0.049aw). The wetting time of GA and GA-HC microcapsules were not significantly different (p>0.05). As a result, this study showed that hemicelluloses can be used as the coating material with gum arabic for food microencapsulation.

Synthesis, characterization and emulsification properties of dodecenyl succinic anhydride derivatives of gum Arabic

Gum Arabic, GA, has been chemically modified using dodecenyl succinic anhydride (DDSA) in aqueous solution and the products have been characterized and their solution and emulsification properties evaluated. FTIR was used to confirm that derivatisation had occurred and the hydrophobe incorporation and reaction efficiency was determined by a simple titration method. The derivatives, DGA5 and DGA10 were found to contain 5 and 10 %w/w DDSA respectively. Surface tension and dye solubilisation measurements demonstrated that the modified GA samples aggregated in solution at a specific concentration, referred to as the critical aggregation concentration, CAC. The value of the CAC was found to be a function of the degree of substitution and values of 0.1% and 0.04% were obtained for DGA5 and DGA10 respectively. The emulsification properties of the polymers were assessed by determination of the droplet size as a function of polymer concentration and time using laser diffraction. The droplet size decreased for all samples as the polymer concentration increased but the minimum droplet size obtained increased in the order DGA10 < DGA5 < GA indicating enhanced emulsification efficiency with increasing hydrophobe content. The effect of ageing on emulsion stability was assessed and the droplet size of emulsions prepared with GA and DGA5 increased with time but remained constant for samples prepared with DGA10. Emulsion creaming was followed using the Turbiscan and it was noted that DGA5 and DGA10 were much more effective than GA at reducing creaming. The results have demonstrated that the modified gum Arabic samples have potential application for microencapsulation.

English

A study was done to determine the influence of&nbsp;Acacia senegal&nbsp;variety&nbsp;senegal&nbsp;and var.kerensis&nbsp;on quality of gum arabic in Solit, Kapkun, Kimorok and Maoi,&nbsp;Marigat division, Baringo District.&nbsp;Soil and gum arabic samples were collected, dried and analysed to establish their chemical characteristics. Gum nitrogen from&nbsp;A. senegal&nbsp;variety&nbsp;senegal&nbsp;in Kapkun and Solit was negatively correlated to soil nitrogen (r = -0.28), while gum nitrogen from variety&nbsp;kerensis&nbsp;at Kimorok and Maoi was positively correlated to soil nitrogen (r = 0.16), respectively. High nitrogen content in soils was significantly correlated to high content of nitrogen (0.30%) in gum arabic obtained from the&nbsp;A. senegal&nbsp;varieties. Gum copper was highly correlated to soil copper (r = 0.09; P &lt; 0.01), soil iron was highly correlated to gum iron (r = 0.09; P &lt; 0.05) and soil manganese and gum manganese was negatively correlated (r = -0.08; P &lt; 0.05). Gum zinc from&nbsp;A. senegal&nbsp;variety&nbsp;kerensis&nbsp;in Kimorok and Maoi was positively correlated to soil zinc (r = 0.53; P &lt; 0.05), while gum nitrogen from&nbsp;A. senegal&nbsp;variety&nbsp;senegal&nbsp;at Kapkun and Solit was negatively correlated to soil nitrogen and (r = -0.15), respectively. Nitrogen, iron, manganese and zinc contents in gums from&nbsp;A. senegal&nbsp;varieties fell within the ranges of the international standard specifications (0.26 to 0.39% N, iron (730 to 2490 ppm), manganese (69 to 117 ppm) and zinc (45 to 111 ppm), respectively.&nbsp;A. senegal&nbsp;variety&nbsp;senegal&nbsp;in Solit and Kapkun produced better quality of gum arabic than&nbsp;A. senegal&nbsp;variety&nbsp;kerensis&nbsp;in Kimorok and Maoi. &nbsp; Key words:&nbsp;Study sites,&nbsp;Acacia senegal&nbsp;varieties, chemical properties, gum quality.

Physical and Chemical Stability of Gum Arabic-Stabilized Conjugated Linoleic Acid Oil-in-Water Emulsions

Oil-in-water (O/W) emulsions have been used as a delivery system to protect conjugated linoleic acid (CLA), a polyunsaturated fatty acid, from oxidation. Conventional gum arabic (GA) and two matured gum arabic samples (EM2 and EM10) were used as emulsifiers to prepare CLA-in-water emulsions. The emulsions have optimal physical and chemical stability at gum concentrations of 5% for all three gums. Emulsions with higher gum concentrations are more susceptible to lipid oxidation. This is attributed to reduced physical stability at higher gum concentrations because of the coalescence and depletion-induced flocculation of the emulsion droplets. The prooxidants iron and copper intrinsically contained in the gums could also contribute to this instability. Among the three gums, EM10 provides the most effective protection for CLA both physically and chemically, because of its superior interfacial properties over GA and EM2.

Assessment of physical properties of Gum Arabic from Acacia Senegal varieties in Baringo District, Kenya

A study was conducted to assess the physical properties of gum arabic obtained from two Acacia senegal varieties (var.senegal and var.kerensis). in Marigat division, Baringo district. Gum arabic samples from the experimental sites at Solit, Kapkun, Kimorok and Maoi were collected, dried and analysed to establish their physical characteristics. Moisture content in gum arabic obtained from variety kerensis in Kimorok and Maoi (17.5 ± 1.00 and 15.4 ± 0.50%) were significantly higher (P 0.05) from those of variety senegal found in Kapkun and Solit (33.0 and 32.96%), respectively. Ash content in gum arabic from variety senegal in Solit and Kapkun (2.94 and 3.16%) was higher (P < 0.05) than those of variety kerensis found in Kimorok and Maoi (2.88 and 2.72%). In Kapkun, volatile matter in gum arabic from variety senegal (64.2%) was higher (P < 0.05) than the quantities of variety kerensis found in Kimorok, Solit and Maoi (63.8, 63.7 and 63.6%), respectively. Moisture content in gum arabic from variety senegal in Solit and Kapkun (15.0 ± 0.40 and 14.9 ± 1.80%) fell within international specifications (13 to 15%), while variety kerensis in Kimorok and Maoi (17.5 and 15.4%) fell outside the specifications. Moisture, ash and volatile matter contents in gum arabic from A. senegal variety senegal were 14.9, 3.16 and 64.24%, while A. senegal variety kerensis had 15.2, 2.88 and 63.8%, respectively. Moisture content in gum arabic from A. senegal variety senegal fell within international specifications while A. senegal variety kerensis fell outside the specifications. Ash, volatile matter and internal energy contents in gum arabic from A. senegal variety kerensis and variety senegal fell within the specifications. The gum arabic from A. senegal variety senegal in Solit and Kapkun was of better quality than that of A. senegal variety kerensis in Kimorok and Maoi.