Viscoelastic characterization of gum arabic and maize starch mixture using the Maxwell model

• Published in: Carbohydrate polymers 2005-10, Vol.62 (1), p.11-18
• Main Authors: Jiménez-Avalos, H.A., Ramos-Ramírez, E.G., Salazar-Montoya, J.A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Gum arabic; Maize starch; Maxwell model; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Viscoelasticity
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2005.07.007

The aim of this study was the viscoelastic characterization of dispersions of gum arabic (GA) at 25 and 35% (w/v), maize starch (MS) at 3 and 5% (w/v) and their mixtures (GA/MS) using dynamic oscillatory and creep tests. The studied dispersions presented G′ values of up to 8.5, 12.7 and 3.5 greater than those of G″ in GA, MS and GA/MS dispersions, respectively, showing a predominantly elastic behavior. Creep curves revealed that in 5% (w/v) MS dispersions, recovery reached 96.7%; thus, they behaved as a viscoelastic solid. However, by adding gum arabic into the mixtures (GA/MS), no recovery was observed and they behaved as viscoelastic fluids. In relation to Maxwell model parameters, viscosity (η 0) was approximately 6 Pa s for GA and GA/MS dispersions, and 1.12×10 6 Pa s for MS dispersions. Mixture relaxation time ( λ rel) was between 0.023 and 220 s and instantaneous compliance ( J 0) was greater than retarded compliance ( J 1) regardless of MS concentration.