I've noticed that a banana in the refrigerator will turn pitch black in just a few hours. Why is this?
It is because, the water that is present inside the veins of bananas get expanded when is cooled from 4 deg celsius to 0 deg. at refrigerator. As the expansion of veins reaches climax it can't be holded any more and finally bursts causing blackening of bananas. It is included in the topic ANOMALOUS EXPANSION OF WATER!!!!