Are rotten fruits and vegetables pure (tahir) or impure (najis)?

The basic principle concerning objects is their purity, unless there is evidence indicating their impurity. There is no evidence to suggest the impurity of altered fruits and vegetables. Disgust with something does not mean it is impure. The Prophet, peace and blessings be upon him, ate from rancid fat (fat that had changed in color and taste), which indicates the purity of food that has undergone alteration. Anas described the food during the Battle of the Trench as being disgusting and having a foul odor, yet it was still eaten.