materials of a surface mesh element

Hi everyone ,
I’m looking for a possibility to distinguish the different materials that belong to a single surface-mash-element (for example: a triangle) in matlab? For better understanding - my problem in a second way. Starting from a model containing a single meshed surface. Each mesh-element is now between two materials. So how do I get knowledge about the two materials/groups/… the element is between?
Thanks for help!