Each of the words below can be changed into a related word by the addition of one letter and anagramming the result. The added letter is different for each word. What are the new words and how are they related?

CLOY
MANOR
MAD
GOAD
AORTIC
CARDED

Answers to added letters:

CLOY + B
MANOR + O
MAD + E
GOAD + U
AORTIC + T
CARDED + H

Answers to new words:

COLBY
ROMANO
EDAM
GOUDA
RICOTTA 
CHEDDAR - - - All are types of cheese.