Here are some adjectives you could use to describe food.
beiskur - bitter
bragðgóður - tasty
bragðvondur - bad-tasting
feitur - fat
ferskur - fresh
harður - hard
hrár - raw
magur - lean
meyr - tender
mjúkur - soft
safaríkur - juicy
seigur - tough
saltur - salty
stökkur - crispy
súr - sour
sætur - sweet
þurr - dry
Jon