ESTIMATING RHEOLOGICAL PROPERTIES OF YOGURT USING DIFFERENT VERSIONS OF THE FREUNDLICH MODEL AND DESIGN MATRICES

Abstract

The rheological properties described by the consistency coefficient and flow behavior index can be estimated from the relationship between shear stress and shear strain rate following a Freundlich model. An additional rheological property of concern to food scientists studying yogurt is yield stress. They extend the Freundlich model to include a three-parameter model called the Herschel-Bulkley model. In addition, the Herschel-Bulkley model is often linearized by taking logarithms of both sides. An additional complication is the viscometer limits the range of shear strain rates. The objectives of this study are to compare parameter estimates from the three models and to investigate the effects of different designs on the models.