Mathematical models for prediction of rheological parameters of pineapple juice

Abstract

Rheological characteristics of pineapple juice have been investigated and rheological parameters were evaluated using rotational viscometer at temperatures 20, 30 and 40*C at concentration 26.77, 18.99 and 14 % total solids. The experimental results followed the power law model for the best fit and the values of flow behaviour index (n) was less than unity (0.08 to 0.87) at all temperatures and concentrations indicating the shear thinning (pseudoplasticity) nature of juice. An obvious correlation between consistency coefficient in the range of 0.1 - 37.16 Pa.sn and inverse absolute temperature has been exhibited by Arrhenius model. The Power equation indicated that the consistency coefficient increased non-linearly with an increase in concentration. Mathematical models were developed for prediction of the consistency coefficient as a function of temperature and concentration. A good agreement was observed between experimental and theoretical values of the consistency coefficient predicted by models. The magnitude of activation energy was found to be in the range of 3.67 to 4.62 kJ/mol.K. Copyright ©2008 The Berkeley Electronic Press. All rights reserved.