Modelling of rheological behaviour of macaíba pulp at different temperatures

ABSTRACT Fruit pulps undergo temperature variations during processing, leading to viscosity changes. This study aimed analyse the rheological behaviour of macaíba pulp at different temperatures (10 50 ºC, with 5 ºC increments) and speeds (2.5 200 rpm, totalling 17 speeds). Experimental measurements were performed in a Brookfield viscometer, fitting Ostwald-de-Waele, Mizrahi-Berk, Herschel-Bulkley, Casson models experimental data shear stress as function rate. Among used, Mizrahi-Berk model (R² > 0.9656 average percentage deviation - P ≤ 4.1%) was found best fit rheogram data. Macaíba exhibited non-newtonian characterised pseudoplastic. It showed fluid indexes below unity under studied conditions, decreases apparent rate increased. Such could be described by Arrhenius equation. The Falguera-Ibarz 0.99 10%) fitted used represent pulp. activation energy values ranged between 17.53 25.37 kJ mol-1, showing like other fruit pulps.