Rheological Quality and Influence Factor of Moroccan Prickly Pear Juice (Opuntia ficus indica L.)

Abstract

Rheological properties of prickly pear juice fruit of cactus (Opuntia ficus indica) and impacts of temperature, shearing rate and pH value on its viscosity were studied using a rotational concentric cylinders viscometer. The results show that the viscosity of prickly pear juice decreases with the increase of its temperature and shearing rate. The solution presents pseudo-plasticity fluid, which shows the characters of shear thinning as follows: first, its viscosity decreases gradually as the temperature increases. The viscosity decreases sharply at both acid and alkaline conditions, indicating that it is influenced apparently by pH value.

Keywords: Prickly Pear, Juice, temperature, shearing rate, pH, Viscosity