Half-orc / half-elf undead question

[Murdock Mudeater]

Do undead half-orcs/half elves retain their subtypes when turned into undead due to their Orc/Elf Blood racial trait?

[Charles Scholz]

Unless becoming undead would affect a specific aspect of their racial trait, they should have it.
One thing eliminated would be ferocity that lets someone keep fighting even when negative HP.
Once an undead hits 0 HP they are destroyed, vanquished or as in the case of vampires, become mist and escape to their coffins to regenerate.

[Dasrak]

There is no explicit rule as to whether creatures whose type changes due to a template also lose their subtype, and unfortunately Paizo has been inconsistent with their published statblocks. For instance the vampire example from bestiary 1 loses its subtype, but the vampires from the monster codex do not.