The Effect of pH and Temperature on the Rheological Behavior of Dulce De Leche, A Typical Dairy Argentine Product

The rheological behavior of commercial samples of Dulce de Leche (sweet milk) for household and confectionery use was studied. Both products have thixotropic and pseudoplastic characteristics. Apparent viscosity, determined at 25, 40, and 55°C, demonstrated that this magnitude decreased with increas...

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Publicado: 1991
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00220302_v74_n5_p1497_Rovedo
http://hdl.handle.net/20.500.12110/paper_00220302_v74_n5_p1497_Rovedo
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Sumario:The rheological behavior of commercial samples of Dulce de Leche (sweet milk) for household and confectionery use was studied. Both products have thixotropic and pseudoplastic characteristics. Apparent viscosity, determined at 25, 40, and 55°C, demonstrated that this magnitude decreased with increased temperature. Activation energies were 9.9 and 10.4 kcal/mol for household and confectionery types, respectively. Apparent viscosities of household samples were determined at pH = 3.0, 6.1, and 8.3. At acid pH, the apparent viscosity was lower than that of the original sample (pH = 6.1); at alkaline pH viscosity was higher than that of the original. The effect of pH becomes more pronounced with time. From shear stress and shear rate flow diagrams, the Herschel-Bulkley model was adequate for both types of Dulce de Leche investigated. © 1991, American Dairy Science Association. All rights reserved.