Density and viscosity of Malus floribunda juice as a function of concentration and temperature

Density for cloudy and depectinised juice of Malus floribunda was determined in a concentration range from 17 to 70 degrees Brix at 25 degrees C. Density values were similar to the ones of common apple and were linearly correlated with soluble solids concentration. The influence of temperature and concentration on the rheological behaviour of depectinised juice of Malus floribunda has been studied in a temperature range from 10 degrees C to 60 degrees C, and concentrations between 40 and 70 degrees Brix. The depectinised juice has Newtonian behaviour and viscosity variation with temperature following the Arrhenius-Guzman equation, with activation energy values between 26.6 and 64.8 kJ gmol(-1). A relationship between viscosity, temperature and soluble solids concentration has been proposed. (C) 1999 Elsevier Science Ltd. All rights reserved.