EFFECT OF TEMPERATURE AND CONCENTRATION ON RHEOLOGICAL PROPERTIES OF CAROB JUICE


Yılmaz M. Y. , DOYMAZ İ.

LATIN AMERICAN APPLIED RESEARCH, vol.46, pp.87-92, 2016 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 46
  • Publication Date: 2016
  • Title of Journal : LATIN AMERICAN APPLIED RESEARCH
  • Page Numbers: pp.87-92

Abstract

A study on the rheological behaviour of carob juice was carried as a function of solid concentration, in the range 25-45 degrees Brix, at different temperatures (20-60 degrees 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 (R-2). The effect of temperature on viscosity was evaluated by using an Arrhenius type equation. The activation energy (E-a), at a shear rate of 12.2 s(-1), was found in the range of 1.77-10.25 kJ/mol.