Edible internal parts of an animal, such as the heart and liver (5)
I believe the answer is:
offal
(Other definitions for offal that I've seen before include "Liver, lungs etc" , "Heart, liver, kidney etc" , "Liver, kidneys etc - rubbish" , "Animal entrails and internal organs as rubbish" , "Entails and organs of animals, rubbish" .)