Enhancement effect on apparent viscosity of aqueous tragacanth gum dispersions promoted by sugars |
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Authors: | Claudia Silva María D. Torres Ramon Moreira Francisco Chenlo |
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Affiliation: | Department of Chemical Engineering, Universidade de Santiago de Compostela, Santiago de Compostela, E‐15782, Spain |
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Abstract: | Flow curves of aqueous dispersions of tragacanth gum (T) with sucrose and glucose at different temperatures were determined using a controlled‐stress rheometer. The effect of sodium chloride without or with sucrose (at the highest content) on the rheology of T dispersions was evaluated. The presence of sucrose and glucose promoted a noticeable enhancement impact on the apparent viscosity of aqueous T dispersions, which depended on sugar type/content, shear rate and temperature. In all cases, the glucose addition led to the largest enhanced viscosities at low shear rates (<10 s?1) and temperature. The joint action of sugar and salt exhibited a notable effect on apparent viscosity at low shear rates, softening the strong shear‐thinning behaviour of T samples. Flow curves of T in the presence of sugars were satisfactorily described by the Cross‐Williamson model, being semi‐empirical correlations of the model parameters with ingredients content and temperature stablished. |
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Keywords: | Biopolymer glucose rheology sodium chloride sucrose |
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