The difference between Spoilt and Unspoilt

When used as adjectives, spoilt means having lost its original value, whereas unspoilt means not spoilt, decayed or corrupted.

check bellow for the other definitions of Spoilt and Unspoilt

Spoilt as an adjective (UK):

Having lost its original value
Spoilt as an adjective:

Of food, that has deteriorated to the point of no longer being usable or edible.
Spoilt as an adjective (of a person, usually a child):

Having a selfish or greedy character, especially due to pampering