Modeling the temperature effect on the flow behavior of sweet potato puree

A study was conducted to investigate the effect of temperature on viscosity of sweet potato (SP) puree. Rheological data of the puree were measured us ing a Bohlin VOR Rheometer. Shear rates employed ranged from 0.01-921 s(-1) . Thermal scans were run at 15, 25, 40, 60, 75, and 90C. The puree exhibite d "shear thinning" behavior with a yield stress value of 10 Pa at each temp erature tested. The characteristic of the flow behavior of the puree was de termined by fitting the experimental data to Herschel-Bulkley, Casson and M odified Casson models. The model with the best Pt was then used to represen t the combined effect of shear rate and temperature on the apparent viscosi ty of SP puree in a model based upon the Modified Casson model. The model w as validated using data for SP puree samples at 50C. Results showed that, w ithin the experimental conditions used in this study, the model could adequ ately predict apparent viscosities of sweet potato puree processed at diffe rent temperatures.