High-speed 4D computed tomography for uncovering the dynamics of oil uptake in deep-fried food products

Abstract Oil acts as a high-temperature heating medium while also contributing to the organoleptic properties in energy dense deep-fried foods. The amount of oil absorbed is associated with the rapid structural deformation of food during deep-frying, creating pathways for oil to enter the internal microstructure. Here, we describe a 4D imaging system (three spatial dimensions and time) that uses fast synchrotron radiation tomography for in-situ visualization of the highly dynamic deep-frying and post-frying cooling processes. We use dynamic imaging and 3D quantification to show that the continuously evolving connectivity of the heterogeneous porous microstructure in a wheat flour-based dough is altered by the deformations induced during and after deep-frying. The resulting pore network integrity, more than porosity, significantly impacts the rate of oil uptake and its distribution. The findings also suggest that a two-stage deep-frying operation at different temperatures can help reduce oil content while achieving a desired crust.