Physical properties of clarified cape gooseberry (Physalis peruviana) juice as a function of concentration and temperature

The effect of concentration (20 to 50 °Brix) and temperature (20 to 50 °C) on density and viscosity of clarified cape gooseberry (Physalis peruviana) juice was studied, using a randomized arrangement of two factors: temperature with five levels, concentration with seven levels and three repetitions. In addition, the freezing point of cape gooseberry juice at various concentrations was determined. Density and viscosity values of juice decreased with increasing temperature and increased with increasing concentration of soluble solids. The effect of temperature on viscosity at different concentrations of juice was described by an Arrhenius type relationship while the activation energy of flow was found to be in the range of 7.02 to 17.62 kJ/mol. The freezing points of juice at various concentrations were determined based on the cooling curves. The results were compared with those estimated from a model applicable to fruit juices, with an average relative error of 6.6%.