This is the 14135th most frequent Turkish word.
mutfakları
"Kitchens" (plural form).
Here, 'mutfakları' refers to the kitchens belonging to 'them' (their kitchens). It is the plural form and genitive case indicating possession.
Onların mutfakları çok düzenli.
Their kitchens are very organized.
In this sentence, 'mutfakları' is used to describe the kitchens specific to houses ('Evlerin' - meaning 'of the houses'), in the plural and genitive context.
Evlerin mutfakları genelde geniştir.
The kitchens in houses are usually spacious.
Here, 'mutfakları' means 'the kitchens' in general, used in the accusative case to indicate the object of the action (to renovate the kitchens).