Compositional Analysis and Rheological Properties of Gum Kondagogu (Cochlospermum gossypium): A Tree Gum from India

Abstract

Gum kondagogu ( Cochlospermum gossypium) is a tree exudate gum that belongs to the family Bixaceae. Compositional analysis of the gum by HPLC and LC-MS revealed uronic acids to be the major component of the polymer ( approximately 26 mol %). Furthermore, analysis of the gum by GC-MS indicated the presence of sugars such as arabinose (2.52 mol %), mannose (8.30 mol %), alpha- d-glucose (2.48 mol %), beta- d-glucose (2.52 mol %), rhamnose (12.85 mol %), galactose (18.95 mol %), d-glucuronic acid (19.26 mol %), beta- d-galactouronic acid (13.22 mol %), and alpha- d-galacturonic acid (11.22 mol %). Gum kondagogu, being rich in rhamnose, galactose, and uronic acids, can be categorized on the basis of its sugar composition as a rhamnogalacturonan type of gum. The rheological measurements performed on the gum suggest that above 0.6% (w/v) it shows a Newtonian behavior and shear rate thinning behavior as a function of gum concentration. The viscoelastic behavior of gum kondagogu solutions (1 and 2%) in aqueous as well as in 100 mM NaCl solution exhibits a typical gel-like system. The G' (viscous modulus)/ G'' (elastic modulus) ratios of native gum kondagogu (1 and 2%) in aqueous solution were found to be 1.89 and 1.85 and those in 100 mM NaCl to be 1.54 and 2.2, respectively, suggesting a weak gel-like property of the polymer. Crossover values of G' and G'' were observed to be at frequencies of 0.432 Hz for 1% and 1.2 Hz for 2% for native gum in aqueous condition, indicating a predominantly liquid- to solid-like behavior, whereas crossover values of 2.1 Hz for 1% and 1.68 Hz for 2% gum in 100 mM NaCl solution suggest a larger elastic contribution.

Rheological Properties of Six Plant-Based Seed Gums

“…The region that complex modulus G* does keep consistent with the oscillation changes is named viscosity region [21]. 2% strain was used to determine the rheological properties of six gum samples.…”

Rheological Properties of Five Plant Gums

“…All dynamic viscoelastic properties are tested in the linear viscoelastic range which the complex modulus (G*) keeps steady with the oscillation changes [18]. Figure 7 shows the variation in G'(storage modulus) and G"(loss modulus) with the increase of temperature.…”

Green Synthesis: Nanoparticles and Nanofibres Based on Tree Gums for Environmental Applications

“…The important tree exudate gums available on the market are gum arabic (GA), gum karaya (GK), gum tragacanth (GT), kondagogu gum (KG), and gum ghatti (GG). Extensive research has been carried out on various aspects of these tree gum polysaccharides, which includes their availability, molecular weight distribution, chemical structures, and food & non-food applications [77][78][79][80]. None of the three gums are produced in developed countries.…”

“…Even though gum karaya, also known as Indian tragacanth, and KG are classified in the same group, there are considerable differences in their physical and chemical properties [101,102]. Extensive research has been carried out on KG (Cochlospermum gossypium), a gum extracted from kondagogu tree, which grows in India, including its morphological, physical and chemical, structural, rheological, pharmaceutical emulsifying properties and its toxicological evaluation as a food additive [79,80,[102][103][104][105][106][107]. Furthermore, this gum can also be used as a biosorbent for the removal of toxic metal contaminants from aqueous environments and also as an environmental friendly material for the stabilization and a reducing agent for the synthesis of metal/metal oxide nanoparticles [108][109][110][111][112].…”