Rheological behavior of pineapple and mango pulps

The rheological behavior of whole and centrifuged mango (Mangifera indica L. var. Keitt) and pineapple (Ananas comusus L. merr var Perola) pulps was analysed at 30 degreesC, in a rotational viscometer Haake Rotovisco RV-20. The experiments were conducted with measuring system of 45 mm diameter parallel plates (PQ45) with gap of 0.5 mm, at shear rates up to 874 s(-1). The rheograms were fitted with Casson, Ostivald-of-Waelle and Mizrahi-Berk (M-B) models. The Brix of pineapple and mango pulps were 16.6 and 13.3 degreesBrix, respectively, and the insoluble solids content was 0.108 g/kg for mango and 0.054 g/kg for pineapple. The best adjustment was obtained with M-B model. It was observed that the pulps presented pseudoplastic behavior, and the suspended solids had great influence on the consistency index. (C) 2002 Elsevier Science Ltd. All rights reserved.