Influence of temperature, ion type, and ionic strength on dynamic viscoelastic, steady-state, and dilute-solution behavior of Melissa officinalis seed gum

摘要

In this study, the rheological properties of Melissa officinalis seed gum (MOSG) as afunction of temperature (25, 35, 45, 55, and 65℃) and salt concentrations (10, 50,100, and 200 ppm NaCl and CaCl_2) were investigated. The power law and Herschel-Bulkley models could describe the rheological behavior of gum dispersions. Theresults showed that the intrinsic viscosity of the samples significantly decreased withincreasing temperature and salt concentration. Steady-state analysis of the samplesrevealed a non-Newtonian, shear-thinning behavior at tested temperatures and concentrations.The apparent viscosity increased with increasing salt concentrations anddecreasing temperature. The results obtained from the frequency sweep test showedthat the loss modulus (G00) values were higher than storage modulus (G0) in the concentrationsof 0.25% to 0.5%, but beyond these concentrations, G0 values weregreater than G00. The elasticity and viscosity of the gum samples increased withincreasing concentration. The results of this study confirmed that MOSG has goodrheological properties and can be used in food and pharmaceutical systems.