Influence of concentration on the steady and oscillatory shear behavior of umbu pulp

Revista Brasileira de Engenharia Agrícola e Ambiental

Maia, Maria C. A.²  Brandão, Edimir M.³  Borges, Soraia V.¹  Pereira, Edimir A.² 

[1] UFLA;Universidade Federal do Rio de Janeiro, Rio de Janeiro;PETROBRAS

关键词: viscosity;    viscoelasticity;    soluble solid content (°Brix)RESUMO Neste trabalho experimental o comportamento reológico da polpa de umbu foi analisado nos estados estacionário (pseudoplaticidade;    viscosidade aparente) e oscilatório (módulos dinâmicos;    viscosidade complexa) determinado na região de viscoelasticidade linear;   

DOI  :  10.1590/S1415-43662008000100013

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

In this experimental work the rheological behavior of umbu pulp has been studied by shear flow (pseudoplasticity, apparent viscosity) and in oscillatory mode (dynamic modules) in the linear domain of viscoelasticity. The studies were carried out with the use of a controlled stress Rheometer Haake RS 100, at different soluble solid concentrations (10, 15, 20 and 25 °Brix), measured at 30 °C. Tests in steady shear were conducted over a shear rate range of 0.1 - 300 s-1 and oscillatory measurements over a frequency range of 0.01 - 100 Hz. The results indicated that umbu pulp behaves as a non-Newtonian fluid, with pseudoplastic characteristics and yield stress appearance and exhibits tixotropic properties. Rheograms were fitted to the Herschel-Bul

【 授权许可】

CC BY-NC