Persian Gum Research Articles

Stabilisation mechanism of various inulins and hydrocolloids: Milk–sour cherry juice mixture

Milk–fruit juice mixtures, such as the mainly acidic nutraceutical soft drinks, usually suffer from phase separation due to aggregation of caseins at low pH. In this study, short‐chain inulin (SCI), native inulin (NI), long‐chain inulin (LCI) and a combination of long‐ and short‐chain inulins (LCI:SCI) (MIX) in different ratios (20:80, 50:50 and 80:20) were added (up to 10% w/v) to a milk–sour cherry juice mixture and their stabilisation mechanisms investigated using rheological, microstructural and zeta potential observations. In addition, gum tragacanth (GT) and Persian gum (PG) as adsorbing and guar gum (GG) as nonadsorbing hydrocolloids were combined with inulin to enhance their stabilising properties. Finally, sensory analyses were carried out on the stabilised samples. According to our findings, LCI fully stabilised the mixture (8% w/v), while LCI: SCI and NI only reduced phase separation at very high concentrations, and SCI had no significant effect on the stabilisation. Moreover, no inulin aggregates and rheological changes were observed with SCI. However, LCI, LCI: SCI and NI formed inulin aggregates and the mixtures became even more viscous and thixotropic (LCI > LCI: SCL > NI). Based on these observations, it can be concluded that chain length and concentration are two important factors that affect the functionality of inulin. On the other hand, the combination of inulin with GT and PG did not have any pertinent effect on the stabilisation. However, the mixture of inulin and GG could stabilise the mixtures at certain ratios and concentrations. Furthermore, in mixtures containing GG and SCI, GG played the main role in the stabilisation by increasing the viscosity and forming gel network.

Solubilisation of Persian gum: Chemical modification using acrylamide

Persian gum (PG), mountain almond tree (Amygdalus scoparia) exudate, is a transparent and natural edible gum which consists of soluble (SFPG, 25–30wt%) and insoluble (IFPG, 70–75wt%) fractions. Therefore, in the present study, using response surface methodology (RSM), the influence of concentration (0.64–7.36wt%), acrylamide (0.070–0.120mol), temperature (19.77–70.23°C), and time (0.32–3.68h) on solubilizing and some other properties of IFPG were investigated. Based on our findings, the highest solubility (64wt%) was achieved at the presence of 6wt% IFPG, and 0.08mol acrylamide at 60°C after 3h. Intrinsic viscosity and molecular weight determination also confirmed modification reaction which led to reduction in molecular weight. In addition, the effect of pH and electrolytes on rheological properties showed that the soluble part of IFPG which modified at optimum conditions had an anionic structure similar to conventional SFPG.

Stabilization of flixweed seeds ( Descurainia sophia L.) drink: Persian refreshing drink

Abstract Flixweed ( Descurainia sophia L.) and London rocket ( Sysyimbrium irio L.) seeds contain quite a number of nutraceuticals and are often used as herbal medicines. In addition, in Iran, they are used to prepare a type of Persian refreshing drink (sharbat-e-khakeshir). Despite their medicinal and nutritious advantages, the precipitation of seeds, is one of the major issues, restricts its commercialization. Therefore, in this study, the effect of different concentrations of native gums [Persian gum (PG) and gum Tragacanth (GT)] as well as their soluble and insoluble fractions on the stabilization, rheological and sensory properties of Persian refreshing drink [Flixweed or London rocket seeds (5 %wt), basil seeds (0.50 %wt), and sucrose (10 %wt)] was investigated. Moreover, the effect of heat treatment and FeCl 3 was studied on the aforementioned characteristics as well as the production of reversible gels. Our findings indicated that PG (1.20 %wt), insoluble fraction of PG (0.80 %wt), GT (0.30 %wt), soluble fraction of GT (0.05 %wt), and insoluble fraction of GT (0.14 %wt) were able to stabilize Flixweed or London rocket seeds in drinks. Furthermore, the presence of FeCl 3 (0.0025 mol/L) led to a reversible gel in the presence of soluble fraction of GT. The rheological properties of stabilized drinks also showed proper fitting with Hershel–Bulkley model. In terms of sensory characteristics, the drink stabilized with soluble fraction of GT (0.05 %wt) showed the highest similarity to control.

Effects of biopolymer ratio and heat treatment on the complex formation between whey protein isolate and soluble fraction of Persian gum

ABSTRACTProteins and polysaccharides are the two most important natural ingredients with unique functional properties. Their interactions can be considered as a route to produce new materials of various technological applications. In this study, the effect of pH (3–7) as well as the mixing ratio of whey protein isolate (WPI)/soluble part of Persian gum (PG) (1:3, 1:1, 3:1, 6:1, and 9:1% w/w WPI/PG) on the complex formation behavior of the two polymers were studied using spectrophotometric and dynamic light scattering techniques, soluble protein measurement, and microscopic observations. Investigating the curves of turbidity versus pH showed that pHc and pHϕ1, which are associated with the formation of soluble and insoluble complexes, moved toward higher pH values by increasing WPI:PG ratio. Increased solubility was observed at pHc > pH > pHϕ1 for all biopolymers mixtures. In addition, lowering the pH toward pHϕ1 resulted in a decrease in the size of complexes, while further decrease of pH beyond this point led to larger particles. No significant difference was noticed between pHc and pHϕ1 of heated and unheated WPI/PG mixtures, although the turbidity of heated samples increased due to the formation of larger aggregates.

Effects of Persian gum and gum Arabic on the survival of Lactobacillus plantarum PTCC 1896, Escherichia coli, Xanthomonas axonopodis, and Saccharomyces cerevisiae during freeze drying

PurposeThe purpose of this paper is to evaluate the protective effects of Persian gum and gum Arabic on the survival of Lactobacillus plantarum subsp. plantarum PTCC 1896, Escherichia coli, Xanthomonas axonopodis, and Saccharomyces cerevisiae during freeze drying.Design/methodology/approachCultures were harvested from the early stationary phase and enumerated after dilution according to the Milse Misra method. Bacterial suspensions were mixed with protective agents and frozen at –80°C before drying in a freeze dryer. Survival rates were determined both immediately during freeze drying and after 14 days of cold storage (at 4°C).FindingsCompared to gum Arabic 5 and 10 percent (W/V) or skim milk 10 percent (W/V), Persian gum 1 percent (W/V) showed no significantly different effects on the survival of Lactobacillus plantarum subsp. plantarum PTCC 1896 (p<0.05). Similarly, no significant differences (p<0.05) were observed between Persian gum 6 percent (W/V), gum Arabic 6 percent (W/V), the combination of Persian gum 3 percent (W/V) and gum Arabic 3 percent (W/V), and skim milk 10 percent (W/V) in terms of their effects on the survival of Escherichia coli. Skim milk 10 percent (W/V) was, however, found to have significant (p<0.05) effects on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. Statistically significant (p<0.05) effects were observed after 14 days of cold storage (4°C) by Persian gum 6 percent (W/V) on the survival of Escherichia coli and by gum Arabic 6 percent (W/V) on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. It was concluded that protective agents could be replaced by Persian gum for its effect on the survival rate of Escherichia coli and by skim milk for its effects on the survival of Xanthomonas axonopodis and Saccharomyces cerevisiae. Persian gum 6 percent (W/V) seemed to be the best protective agent for Escherichia coli during 14 days of its storage as gum Arabic 6 percent (W/V) seemed to have the same performance for Xanthomonas axonopodis and Saccharomyces cerevisiae. Persian gum 1 percent (W/V) was also found an alternative protective agent for the freeze drying of Lactobacillus plantarum subsp. plantarum PTCC 1896.Originality/valueAs Iranian Persian gum is cheap due to its wide availability and seems to have effects similar to those of gum Arabic and skim milk at low concentrations, it may be considered a good candidate for industrial applications.

Optimizing the effects of Persian gum and carrot pomace powder for development of low-fat donut with high fibre content

The objective of present study was to develop and optimize a low-fat high fibre donut formulation using response surface methodology. A 5-level-3-factor central composite rotatable design was employed, where the independent variables were Persian gum (0–1.5g/100g), carrot pomace powder (0–15g/100g) and water (38–53g/100g), while the dependent variables were physicochemical properties of donuts. It was found that Persian gum and carrot pomace powder both effectively contributed to retention of donuts moisture content which in turn led to significant reduction of fat uptake during frying process (p<0.05). Persian gum decreased the donuts firmness while carrot pomace powder adversely affected the textural properties as well as specific volume (p<0.05). Image analysis revealed that carrot pomace powder influenced all the image analysis parameters investigated negatively. Response surface methodology described that donuts with optimum formulation of 1.20g/100g Persian gum, 6.45g/100g carrot pomace powder and 48.16g/100g water had considerably lower fat uptake and acceptable sensory attributes compared to control sample.

Effect of Persian and almond gums as fat replacers on the physicochemical, rheological, and microstructural attributes of low-fat Iranian White cheese.

The effect of Persian and almond gums (0, 0.1 and 0.2% (w/w)) as fat replacers and milk fat (0.4, 0.9, and 1.4% (w/w)) on physicochemical and rheological characteristics and microstructure of low‐fat Iranian White cheese was studied. Persian and almond gums both effectively increased moisture‐to‐protein (M:P) ratio of low‐fat cheese samples which in turn led to a significant reduction in the hardness parameters fracture stress and Young's and storage (G’) moduli (p < .05); however, the effect of Persian gum was more pronounced (p < .01). Gum addition promoted cheese yield and proteolysis rate (p < .05). Response surface optimization described that supplementation of cheese milk containing 0.9% fat with 0.2% Persian gum and 0.12% almond gum would result in a low‐fat cheese with textural properties similar to its full‐fat counterpart. Scanning electron microscopy revealed that the fat replacers produced full‐fat‐like structure in the low‐fat Iranian White cheese, when incorporated at the optimum levels.

Changes in Turbidity, Zeta Potential and Precipitation Yield Induced by Persian Gum-Whey Protein Isolate Interactions During Acidification

To measure the molecular parameters of Persian gum (PG) (gathered from Kazeroon plains/Iran) by gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), water-insoluble part of gum was removed using filtration method. In the following, acidification of whey protein isolate/PG mixture solutions (pH ∼ 7.00–2.00) at different biopolymer mixing ratio (r = 0.1–10) was induced by HCl, allowing turbidity, zeta potential and precipitation yield determinations. Contrary to previous studies, it was demonstrated that more than 93% of gum is composed of large water-insoluble particles and water-soluble part contains heavy and heterogeneous compounds with high weight-average molecular mass (up to 5.11 × 106 g/mol) and high dispersity index (∼2.54–6.64). Acid titration of the mixtures displayed that the net neutrality shifts to the higher pHs by increasing the mixing ratio, and the charge neutralization occurs at pHs near pHopt as well. Generally, the maximum interaction was found for a 1:1 WPI/PG mixture with the highest liquid precipitate yield achieved at pH 3.4. Practical Application Persian gum exudes from the wild almond tree (Amygdalus scoparia), growing in the Middle East countries. The characteristics of this hydrocolloid highly depend on the color of exudate and region of the tree. As a mixture with gum Arabic, it has wide industrial and pharmaceutical applications due to economic reasons and high functionality. However, very few scientific information about this gum has been already published. Some researchers have displayed the emulsifier, stabilizer and fat replacer ability of this gum. The interaction of PG with other biopolymers such as proteins would be beneficial in food and pharmaceutical applications in the form of gels, microcapsules, etc. In this study, we have measured the water-soluble and insoluble fractions and molecular parameters of PG gathered from Kazeroon plains. To have a basic knowledge for our future investigations on encapsulation ability of PG-WPI complexes, titration method was applied for different PG-WPI admixtures.

Development of emulsifying property in Persian gum using octenyl succinic anhydride (OSA)

In the present study, the influence of octenyle succinic anhydride (OSA),gum concentration, pH, temperature and reaction time on esterification of Persian gum (PG), and its soluble (SFPG) and insoluble (IFPG) fractions, were investigated by response surface methodology (RSM) in order to optimize the reaction conditions based on the degree of substitution (DS). The individual effect of all independent variables as well as the interactive effects of temperature–OSA concentration, and OSA–PG concentrations on DS was significant. However, the latter interactive effect (OSA–SFPG) was not significant in case of SFPG. The IFPG did not have any esterification reaction with OSA. The highest DS for PG and SFPG were 0.0285 and 0.0303 at the optimal conditions, respectively. The FTIR spectrums also confirmed the carbonyl group attachment in OSA-PG and OSA-SFPG. The enhancement of emulsifying capability was also confirmed by ECI and EAI values, microscopic images as well as rheological measurements.

Effects of gamma irradiation on some physicochemical and rheological properties of Persian gum and gum tragacanth

In the present study, the effect of various levels of gamma irradiation (0, 4, 8, 16, 30 kGy) on some physiochemical and rheological properties (FTIR, color, pH, water absorption capacity, solubility, stabilizing capability, flow behavior, apparent viscosity, intrinsic viscosity, molecular weight) of powder form of Persian gum (PG) and gum tragacanth (Astragalus campatus gum: ACG) was evaluated. FTIR analysis, intrinsic viscosity and molecular weight were determined to provide more structural information. Based on our FTIR findings, the functional groups were not significantly affected by gamma irradiation. However, it induced significant changes in color, solubility and water absorption capacity (WAC). In terms of PG, the increase in irradiation dose of (4 kGy) almost doubled its apparent (from 19.9 to 33.4 mPa s) and intrinsic viscosity (from 3.72 ± 0.04 up to 8.22 ± 0.17 dl/g), whereas at higher irradiation doses (>4–8 kGy), these parameters decreased. Nevertheless, for GT, significant decrease for apparent and intrinsic viscosity was seen by increasing the irradiation doses, likely due to decreasing of molecular weight and the reduction of side branches and radiolysis of the glycosidic bonds. In addition, the flow behavior of the dispersions shifted from non-Newtonian to Newtonian one. Furthermore, the highest stabilizing capability of PG was seen at 4 kGy in milk sour cherry mixture whereas no significant effect was seen on ACG. Consequently, one can conclude that gamma irradiation could be potentially used at certain dose, as an effective method, to improve some functional properties such as stabilizing ability of PG but not for ACG.

Isothermal titration calorimetric and spectroscopic studies of β-lactoglobulin-water-soluble fraction of Persian gum interaction in aqueous solution

In this work, the interaction between β-lactoglobulin (β-lg) and water-soluble fraction of Persian gum (WPG) was studied under the effects of extrinsic parameters including pH, protein to polysaccharide mixing ratio (MR 8:1–1:4), total biopolymer concentration (TC 0.1–0.6% (w/w)), ion type (Na+ and Ca2+), ionic strength (0–100 mM) and temperature (25, 40 and 55 °C). Soluble complexes were formed at a pH above protein's isoelectric point (pI). MR and TC had significant effects on the values of critical pHφ1 (formation of insoluble complexes) and pHopt (maximum optical density). A decrease in MR (at a constant TC) and in TC (at a constant MR) shifted the values toward more acidic domains; while, the critical pHc (formation of soluble complexes) remained constant. The effect of divalent ions (Ca2+) in preventing the complex coacervation was more than that of monovalent ones (Na+). Increasing the ionic strength had significant effect in decreasing the interaction. In this study, the effects of temperature on the thermodynamic parameters were obvious. Biopolymers binding enthalpy as obtained by isothermal titration calorimetry (ITC) was independent from the temperature in the studied range. Analysis of the temperature effect showed that electrostatic interaction, hydrogen bonding and hydrophobic interactions were involved in the complexation process.

Mechanism of soluble complex formation of milk proteins with native gums (tragacanth and Persian gum)

Charged polysaccharides can link to oppositely charged proteins via electrostatic interaction to prevent aggregation and precipitation of proteins at isoelectric pH. However, attachment of proteins and polysaccharides either may lead to formation of soluble complexes or cause coacervation. Therefore, in the present study, the appropriate ratios of milk proteins–soluble fraction of Iranian native gums were found in order to prevent precipitation formation over a wide range of pH (2–6). Besides, the flow behavior of soluble fraction of native gums as well as their complexes with milk proteins was studied as a function of pH. Based on our results, the appropriate ratio for avoiding precipitation formation in the mixtures of sodium caseinate–soluble fraction of Persian gum, sodium caseinate–soluble fraction of gum tragacanth, whey protein isolate–soluble fraction of Persian gum, and whey protein isolate–soluble fraction of gum tragacanth were 0.4:0.6, 0.4:0.6, 0.4:2 and 0.4:1 (% w/w), respectively. According to rheological experiments, it was found that the whole samples exhibited shear thinning behavior (except the samples contained Persian gum at pHs 2 and 3). Moreover, appropriate rheological model for milk proteins–soluble fraction of gum tragacanth was Power law, in-depending to pH and gum concentration. However, the concentration of gum and pH were effective on the flow behavior of soluble fraction of Persian gum–milk protein complexes.

Whey protein isolate-Persian gum interaction at neutral pH

A better understanding of Whey protein isolate-Persian gum interaction at neutral pH may increases the utilization of Persian gum in foods, pharmaceutical and cosmetic industry. The interactions in a neutral system (pH = 7) containing whey protein isolate (WPI) and the soluble fraction of Persian gum (PG) were studied. The results obtained through Methylene blue spectrophotometry, zeta potentiometry, surface tension measurement and the observation of phase treatment confirmed the presence of interaction between WPI and PG even when both biopolymers were net-negatively charged at neutral pH. The protein-polysaccharide ratio influenced the properties of mixed solution. This effect was more significant at the equal amount of protein and polysaccharide. The research revealed possible weak interactions in WPI-PG mixed system at pH 7.00.

Rheological and Quality Characteristics of Taftoon Bread as Affected by Salep and Persian Gums.

Effects of salep gum at concentrations of 0.5%, 1%, 3%, and 5% (w/w flour basis) and the Persian gum at concentrations of 0.5%, 1%, and 3% (w/w flour basis) and combination of the two gums at concentrations of 0.5% + 0.5%, 0.75% + 0.25%, and 0.25% + 0.75% on rheological properties of the wheat flour dough and quality of Taftoon bread were studied with regard to retardation of staling. Rheological (farinograph and extensograph) characteristics, staling, and organoleptic evaluations were performed on the dough and the resulting Taftoon bread. Statistical results showed that the salep gum at 5% and Persian gum at 3% (w/w flour basis) had a significant effect on the dough properties. Salep and Persian gums when each separately added increased and decreased dough water absorption, respectively. Both hydrocolloids increased the dough resistance to extension and decreased its extensibility. Persian gum shows dual nature in water absorption and some other baking properties. Textural studies revealed that addition of 5% salep gum (w/w flour basis) reduced the bread crumb firmness and delayed the staling process of the Taftoon bread. X-ray diffraction study also confirmed this result.

Stabilization of milk–orange juice mixture using Persian gum: Efficiency and mechanism

Abstract Acidified milk drinks, including milk–orange juice mixture, suffer from serum separation because of low pH (

Production of copper matrix materials with silicon carbide and alumina reinforcements : Z.Abdel-Hamid et al. (Central Metallurgical R. and D. Inst., Cairo, Egypt.) Mater. Letters, Vol 53, 2002, 244–249

Postharvest fruit coatings are an effective method to replace natural waxes lost during washing and handling. The coatings can reduce water loss and impart gloss to the fruit. Edible coatings, instead of synthetic waxes, are perceived to offer advantages with respect to human health concerns and environmental protection. In this research, edible coatings made from relatively inexpensive, easy to dissolve components that are suitable for increasing fruit gloss were studied on ‘Valencia’ oranges during storage. The coating materials included 5, 6 and 7% gelatin, 3.5, 4 and 4.5% Persian gum, 9, 10 and 11% shellac were compared to un-coated control, and fruit coated with a commercial wax. After coating, the fruit were stored for up to 60 days at 5 °C. Every 20 days fruit were removed from storage and evaluated. Scanning electron microscopy images of coated rind surfaces were also obtained. The results indicated that weight loss, fruit firmness, total soluble solids (TSS), titratable acidity (TA), pH, ascorbic acid content, total phenolic content (TPC), total antioxidant capacity (TAC) and respiration rate were affected by the coatings. Shellac coatings reduced weight and firmness loss. As the storage time was increased fruit TA and ascorbic acid content decreased, and pH, TPC and TAC increased. Glossiness was observed in all coatings, however, with increasing storage time, fruit coated by gelatin and Persian gum coatings, showed visible cracks. Shellac was the best coating as it dried quickly, forming a not sticky and odorless coating, and gave highest fruit gloss.

Effect of gum tragacanth size reduction on DTA and TG behaviour and its relationship to solution viscosity

The effect of particle size reduction on the hydrocolloid solution viscosity of standardized grades of Persian gum tragacanth have been investigated. The DTA and TG techniques used to identify the behaviour of gum on size reduction shows that the structure of the gum changes by fine grinding and the reduction of its solution viscosity could be attributed to the loss of the combined water which binds individual gum molecules by hydrogen bonding. The thermal methods with the relating features are discussed.