The rheological behavior of the industrialized acerola juice was studied at different soluble solids concentrations 4, 7, 10, 13 and 16ºBrix and temperatures from 5 to 85ºC, using a concentric cylinder rheometer. Rheograms were fitted according to the following models: Ostwald-de Waele or Power Law, Herschel-Bulkley, Mizrahi & Berk and Casson. The best results were obtained using the Herschel-Bulkley model and the low values presented by the behavior index (0,338 < n hb < 0,759) confirm the pseudoplastic behavior of the acerola juice. An equation similar to the Arrhenius one (etaa = eta0 exp(Eat/RT)) described the effect of the temperature on the acerola juice. The results also showed that the activation energy decreases with the increasing in juice concentration, varying from 3.50kcal/gmol (4ºBrix) to 1.79kcal/gmol (16ºBrix). Potential and exponential models were tested considering the apparent viscosity data as a function of the soluble solids concentrations. For this purpose, the potential model showed the best performance.
acerola; rheology; concentration; temperature
