Modeling Flow and Deformation during Hot Air Puffing of Single Rice Kernels

T. Gulati[1], A. Datta[1]
[1]Cornell University, Ithaca, NY, USA

When rice is subjected to intense heating, it results in rapid evaporation of liquid water to vapor. As a consequence, large pressures are generated within the kernel in a span of 15s resulting in large volume changes causing the kernel to puff rapidly. Under suitable conditions, the ratio of initial volume to volume after puffing could be as high as 10. Rice puffing process is a complex interplay of mass, momentum and energy transport along with large volumetric expansion of the solid. By treating rice as a porous material, a fundamentals-based model of rice puffing that can describe heat and moisture transport, rapid evaporation and large deformations of the solid is presented to understand the factors affecting the puffing process.