RHEOLOGICAL BEHAVIOR OF TOMATO CONCENTRAT ES - EFFECT OF TEMPERATURE AND CONCENTRATION

The rheological properties of various brands of double concentrated to mato paste manufactured in Venezuela were studied. The effect of tempe rature (30, 40, 50, 60 degrees C) and concentration (15, 20, 25 and 30 % total solids) was determined. A concentric cylinders viscometer Haa ke Rotovisco RV-2 was used for this purpose. A psudoplastic behaviour that followed the power law was found. The rheological parameters (con sistency and behavior indexes) that characterize each paste were deter mined for the conditions of the study. According to the statistical an alyses done the consistency index (K) diminished with an increase in t emperature and increased as the concentration increased. An equation t o determine the consistency index as a function of temperature and con centration was obtained. Likewise, it was found that temperature did n ot have a significant effect on the behavior index (n) in the range fr om 30 to 50 degrees C, however this effect was significant for some of the pastes at 60 degrees C. On the other hand, concentration levels a bove 20 % total solids did not have a significant effect on the behavi or index, but a significant effect was determined for 15 % total solid s.