http://www.aseanfood.info/Articles/11014524.pdfThe mass transfer in the core region is assumed to be
due to the capillary flow of water and liquid fat partially
resulting from protein denaturation and melting of solid
fat. The driving force for the capillary flow is the difference
between the water (or fat) concentration at different
locations within the patty during cooking. For the
purpose of this analysis, water (or fat) holding capacity
is defined as the minimum water (or fat) concentration
at which mass transfer could occur within the core region.