The effect of rice kernel microstructure on cooking behaviour: A combined μ-CT and MRI study

0308-8146/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.foodchem.2009.01.089 Abbreviations: E, extruded; EP, extruded and puffe puffed; NMR, nuclear magnetic resonance; MRI, ma parboiled; PDE, partial differential equations; PP, parb tomography; l-CT, micro computer tomography; W demand; WP, wet-processed and puffed. * Corresponding author. Tel.: +386 1 4766552; fax: E-mail address: [email protected] (A. Moh 1 Present address: Faculty of Mathematics and Phy Jadranska 19, 1000 Ljubljana, Slovenia. 2 Present address: Roosevelt Academy, Lange Noord burg, The Netherlands. In order to establish the underlying structure-dependent principles of instant cooking rice, a detailed investigation was carried out on rice kernels that were processed in eight different manners. Milling, parboiling, wet-processing and extrusion were applied, with and without a subsequent puffing treatment. The mesostructure of the rice kernels was examined by DSC and XRD, and the microstructure by l-CT. Hydration behaviour during cooking was studied by MRI in a real-time manner. Based on simple descriptive models, three different classes of cooking behaviour can be discerned. The water ingress profiles during cooking of these three classes matched well with simulations from a model that was based on water demand of the starch mass and the porous microstructure of the kernels. Thus a clear correlation between meso/microstructure of a rice kernel and the cooking behaviour has been established. 2009 Elsevier Ltd. All rights reserved.