Flow characterization of peach products during extrusion

Suitability of Bingham, Herschel-Bulkley, Casson, and Mizrahi-Berk models, to characterize the flow behavior of peach products during extrusion was in vestigated. The Casson equation sufficiently described the flow of peach ex trudates within the 49 to 125 s(-1) shear rate range. As concentration incr eased, yield stress and consistency coefficients increased. A rheological m odel was proposed to describe the viscosity of peach extrudates. The model incorporates the effect of shear rate by the Casson equation and the effect of concentration by a linear expression. The model provided good fit to th e experimental data for peach extrudates reconstituted from drum-dried peac h purees.