Rheology of Mixed Pectin Solutions

Abstract

The effects of sucrose (S) and pectin (P) concentrations and the ratio between two distinct pectins (R) on the rheological behavior of diluted pectin systems were evaluated simultaneously using the surface response methodology. The systems were composed of a mixture of two high methoxy pectins with different degree of methyl esterification values (HM1/HM2) and of a mixture of a high-methoxy with an amidated low-methoxy pectin (HM1/ LMA). For the HM1/HM2 systems, the multivariate analysis showed that the sucrose and pectin concentrations exerted statistically significant (p<0.05) linear effects on the consistency index k and viscosity, the influence of pectin being about five times higher than that of sucrose. The pectin concentration and the ratio between the different pectins were shown to be significant with respect to the rheological parameters of the HM1/LMA systems. Evaluating the influence of the ratio between the different pectins, a synergistic effect on the structure reinforcement was observed when mixing HM1 and LMA in similar proportions, indicating the importance of the presence of hydrophobic interactions between methyl ester groups in addition to the stronger hydrogen bonding in junction zone stabilization. In general, the conditions in which hydrogen bonds were favored in relation to hydrophobic interactions led to systems with higher pseudoplasticity.

Film forming solutions based on gelatin and poly(vinyl alcohol) blends: Thermal and rheological characterizations

“…The organization of the polypeptides (gelatin) in the already known triple helix, as well as the associations of these organized sequences, could take place, depending on factors such as gelatin chemical structure, concentration and temperature, affecting the FFS rheological behavior. This last tendency of macromolecules interaction has been observed in more concentrated systems, with a consequent non-Newtonian behavior (Xiong and Blanchard, 1994;Cuq et al, 1995;Peressini et al, 2003;Sato et al, 2008). Fitzsimons et al (2008) determined flow curves for both unpolymerized and polymerized whey protein isolate (6% WPI, pH 7), alone and mixed with 1% and 2% of type B gelatin and observed Newtonian behavior, with viscosity values around 2 mPa s. When these authors mixed the WPI with 3% or 4% of gelatin, some slight shear-thinning behavior was noticed.…”

Dilute solution properties of Balangu (Lallemantia royleana) seed gum: Effect of temperature, salt, and sugar

“…The intrinsic viscosity, [Á], provides a convenient measure of the hydrodynamic volume occupied by an individual macromolecule coil [21,22,36]. In dilute solutions, the polymer chains are separate, so the intrinsic viscosity is closely related to the size and conformation of the macromolecular chains in a particular solvent [20].…”

“…This effect, which is probed by the intrinsic viscosity, has been extensively used for the analysis or characterisation of various hydrocolloids [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The limiting viscosity number or intrinsic viscosity is a molecular parameter, indicating the hydrodynamic volume occupied by the unit mass of macromolecule and depends primarily on the molecular size, conformation and weight as well as solvent quality [7,8,18,20,27].…”

Steady-shear flow of semidilute guar gum solutions with sucrose, glucose and sodium chloride at different temperatures

“…Considering that apparent viscosity and physical stability of a food formulation could be modified by the presence of such ingredients (sugars and salts), at higher concentrations than the used for hydrocolloids, the study of these mixtures is justified. Some previous studies have hypothesised that the modifications could arise from changes in the hydration of the polymer, rupture of hydrogen bonds, structural change of the solvent and alteration of the hydrocolloid-water interactions (Galmarini et al, 2010;Sato et al, 2008;Seuvre and Mathlouthi, 2009). Though guar gum is a non-ionic polymer, the viscosity of guar gum systems was markedly reduced by the presence of NaCl (Whistler and BeMiller, 1993).…”