Physical properties of food is fundamental in analyzing the unit operations applied in the food industry. The study of these food properties and their responses to process conditions is necessary because they influence of the treatment received during the processing also because they are good indicators of other properties and qualities of food. Viscosity and its variation with concentration and temperature are very important for the food industry in general and for fruit derivatives in particular, since it is necessary for the design and the optimization of several processing operations (e.g., pumping, evaporation, membrane filtration).