How to find out which property is used as a Foreign Key between two entities in code first approach

I'm using Entity Framework 5, code first approach. As there's no built in support for updating child entities in disconnected scenario, I'm building my own mechanism to do that. At some point I need to get the property of an entity with which it has a Foreign Key relationship with another (principal) entity. I've tried to get access to CSpace through

((IObjectContextAdapter)dbContext).ObjectContext.MetadataWorkspace.GetItems<MyEntity>(System.Data.Entity.Core.Metadata.Edm.DataSpace.CSpace)

but here I got a warning that said there's no implicit conversion between MyEntity and System.Data.Entity.Core.Metadata.Edm.GlobalItem.

I can't look for a property that has Foreign Key attribute because in most of my entities I use EF convention to get foreign keys automatically. So how one would go about finding which property is used for foreign key relationship.