LAUSR

Abstract This work evaluates the thermal inactivation of peroxidase and polyphenol oxidase of acai-berry pulp in a continuous pasteurization using a lab-scale pasteurizer with plate heat exchangers (PHEs). Experiments were carried-out at three different acai flow rates with two different pass arrangements of the PHEs. The experimental treatments were simulated by CFD and the numerical results were compared to the experimental data. A better performance of the pasteurizer was noted when the PHEs were set in a series flow arrangement. Heating performance predicted by CFD satisfactorily agreed with the experimental data, especially when the PHEs were set in series flow. Conversely, reasonable deviations between numerical and experimental results of the residual activities of the enzymes occurred, mainly in a series-parallel flow arrangement. Accurately predicting inactivation of thermally-sensitive enzymes is quite difficult in the numerical simulation of complex processes and the reasons why these deviations occurred have been discussed.