Open AccessEFFECT OF TEMPERATURE AND CONCENTRATION ON RHEOLOGICAL PROPERTIES OF CAROB JUICE
Author(s) -
Mustafa Tahsin Yılmaz,
İ̇brahim Doymaz
Publication year - 2016
Publication title -
latin american applied research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.123
H-Index - 23
eISSN - 1851-8796
pISSN - 0327-0793
DOI - 10.52292/j.laar.2016.332
Subject(s) - rheology , shear thinning , viscometer , arrhenius equation , consistency index , chemistry , activation energy , shear rate , viscosity , apparent viscosity , atmospheric temperature range , thermodynamics , viscosity index , materials science , organic chemistry , composite material , scanning electron microscope , physics , base oil
A study on the rheological behaviour of carob juice was carried as a function of solid concentration, in the range 25-45 °Brix, at different temperatures (20-60 °C), with a rotational viscometer. The viscosity decreased with an increase in temperature. Using Herschel-Buckley model, both flow behaviour index (n) and consistency index (K) were determined. The calculated values of flow behaviour index were less than 1 at all temperatures and concentrations. Therefore, the carob juice was well described by the Pseudoplastic behaviour. The Herschel-Buckley model represented well the rheological data, with high values for the determination of coefficient (R2). The effect of temperature on viscosity was evaluated by using an Arrhenius type equation. The activation energy (Ea), at a shear rate of 12.2 s-1, was found in the range of 1.77-10.25 kJ/mol.