A Comparative Study on Physicochemical and Rheological Properties of Imported Tomato Paste in Nigeria

This study was carried out to evaluate the physicochemical properties and rheological behavior of a number of tomato pastes imported by Nigeria food marketers. Chemical composition, color measurement, consistency, viscometry and flow index were determined. There were significant differences among the samples and some of the parameters did not meet the standard requirements set by food drug and administration of (FDA). The viscometry consistency test and flow index at 30 oC, 45 oC and 60 oC indicated the existence of variations among the samples in terms of viscosity and flow index increase as temperature increases. All tomato paste samples in the study were non-Newtonian fluids and the apparent viscosity of the paste decreased with temperature increase. The rheological data obtained were fitted using power law equation. The differences obtained were attributed to raw materials variation and processing conditions.