Cracking prediction of germinated brown rice based on intragranular drying kinetics

Abstract

During convective drying of wet granular materials like germinated brown rice (GBR), excessively high drying rates can lead to crack formation in the particles. However, cracking characteristics of GBR during exposure to different drying stages, unclear especially the critical conditions for cracking. In this study, experiments and numerical simulations were performed in an attempt to predict the cracking behavior of GBR under different drying stages through intragranular drying kinetics. Our results showed that the variations in cracking probability could be divided into three different stages. This phenomenon was dominated by the close relationship between particle strength and moisture gradient. The cumulative effect of moisture gradient is one of the important leading to crack initiation and evolution. Moreover, a prediction model of cracking probability as a function of drying time was proposed. Finally, the critical water evaporation coefficient was introduced to quantify the cracking safe region of GBR.