Study of rheological properties of açai berry pulp: an analysis of its time-dependent behavior and the effect of temperature

Abstract

The industry of açai-based products has been growing in the last few years. Knowledge about the physical properties of açai pulp, including its rheology, is essential to the optimization of industrial processes. This work presents the rheological behavior of açai berry pulp in relation to the effects of shear rate, temperature, and time of shearing. The entire study was carried out in the temperature range of 10-70 °C. Açai pulp showed a non-Newtonian, pseudoplastic, and time-dependent behavior. Four upward and backward shear rate cycles were evaluated, resulting in complex hysteresis loops, in which thixotropy and anti-thixotropy zones were observed. Downward flow curves could be satisfactorily represented by the Power-Law rheological model. The stress profiles as a function of shear rate obtained in the first upward curves suggest a breakdown of the initial fluid structure at low shear rates. Tests were also carried out at a constant shear rate of 20 s and, in this case, the Weltman model of thixotropy satisfactorily fit the experimental data. The activation energy, which was calculated by the Arrhenius equation, was 29.0 kJ/mol. The achievements of this work may be useful to further studies about açai pulp rheology and may contribute to process design in the açai industry.

Effects of three gelling agents on the shelf life and the rheological, physicochemical, nutritional, microbiological, and sensory characteristics of aguaymanto compote (Physalis peruviana L.)

“…The viscosity also decreased over time for the three gelling agents and four temperatures. Similar trends were reported in acai berry pulp and strawberry compote (Costa et al, 2018;Obradovic et al, 2020). The apparent viscosities corrected showed a very small difference for the four temperatures studied and similar behavior among the gelling agents used for aguaymanto compote formulation.…”

Formulation, Characterization, and Determination of the Rheological Profile of Loquat Compote Mespilus Germánica L. through Sustenance Artificial Intelligence

“…Te similar work is reported by Perez and Mera [46], for loquat compote (62.2 ± 2.6 to 66.1 ± 2.2) %. By Quintero et al [59] and Camayo-Lapa et al [60] for pumpkin.…”

Impact of maturity on mechanical and textural properties and rheological properties modeling of wood apple fruit (Limonia acidissima)

“…The rheological properties are the important fundamental property beneficial to characterize the food representing the flow behavior and deformation of the wood apple pulp during several processing operations such as mixing, pumping in pipes, homogenization, agitation, evaporation, packaging, and storage involved in the development of value‐added products (Payne & Reyes‐De‐Corcuera, 2021; Sonawane, Pathak, & Pradhan, 2020). The rheological properties of food depend on the shearing stress which causes the change in viscosity of the food determining the non‐Newtonian behavior (Costa, Arouca, Silva, & Vieira, 2018; Quintana, Machacon, Marsiglia, Torregroza, & García‐Zapateiro, 2018). The rheological flow behavior of pulp can be characterized by the shear stress, viscosity, shear rate, loss modulus, storage modulus, and complex viscosity.…”