Abstract
The rheological properties of tomato concentrates produced by hot and cold break have been extensively studied by many authors. Only a few studies, however, focus specifically with the rheology of reconstituted concentrates from tomato powders. In this study, the rheological properties of reconstituted tomato concentrate from lyophilized freeze-dried tomato juice were evaluated using rotational viscometer at temperatures 20 °C, 30 °C, 40 °C, 50 °C, and 60 °C and at concentrations of 9.7%, 12.9%, 20.5%, and 26.8% total soluble solids. Using power law model, both flow behavior index (
n
) and consistency coefficient (
k
) were determined. The calculated values of flow behavior index (
n
) were less than unity (0.03–0.28) at all temperatures and concentrations indicating the shear-thinning characteristic of the concentrate. The effect of temperature and concentration on the consistency coefficient (
k
) was studied. Positive correlation between
k
in the range of 1.57 and 38.33 Pa s
n
and inverse absolute temperature (1/
T
) has been shown by Arrhenius model. Additionally, linear correlation between consistency coefficient (
k
) and concentration (
C
) was determined. The activation energies were found in the range of 3.63 and 7.36 kJ/mol K depending on concentration. The results of this study might be useful to improve the design of processing operations dealing with tomato powder reconstitution.