Rheological Evaluation of Acerola Pulp In Natura and Reconstituted Powders Obtained by Foam-Mat Drying

Acerola is a fruit rich in vitamin C and antioxidants, but it has a short shelf life. Foam-mat dehydration is a promising method for extending the shelf life, but it can change the rheological properties of the powder. Therefore, the present study aimed to evaluate the rheology of acerola fresh pulp and the reconstituted powder, obtained by drying at 60 °C using the foam-mat method with the additive Emustab (4%), to indicate which powder concentration possesses similar rheological properties to the fresh pulp. The experiment was performed with different concentrations of reconstituted powder in deionized water (2, 4, 6, 8 and 10%, w/v). The Herschel–Bulkley model was the one that adequately adjusted to the experimental rheological data, showing that the reconstituted powder and fresh pulp are non-Newtonian fluids with pseudoplastic behavior and initial shear stress. Shear stress rose and apparent viscosity decreased with increasing shear rate, regardless of the concentration. Emustab did not modify the rheological characteristics of the acerola pulp, which maintained the non-Newtonian fluid characteristic. The 2% concentration provides a reconstituted product more like the fresh pulp.