Viscosity of concentrated strawberry juice. Effect of temperature and soluble solids content

The rheological behaviour of concentrated strawberry juice has been studied over a wide range of temperatures (10-60°C) and concentrations (50-67.1°Bx), using rotational rheometer with coaxial cylinders as a measuring system. On the base of the obtained results it was shown, that concentrated strawberry juice has a Newtonian behaviour. The values of viscosity strongly depend on temperature and soluble solids content and were in the range from 8.6 to 541.2 mPaˇs. The effect of the temperature on the viscosity of that juice was described by an Arrhenius equation. To study effect of concentration on the viscosity, the power-law and exponential equations were used. Finally, two equations described combined effect of temperature and soluble solids content on the viscosity of concentrated strawberry juice were obtained.