Penicillium expansum

Penicillium expansum is a blue mold fungus that causes one of the most economically damaging post-harvest diseases of apples, entering fruit through bruises or punctures and producing soft decay with white mycelium that turns blue-green as it sporulates. It also infects pears, strawberries, tomatoes, corn and rice, and thrives in the cool, wet conditions typical of fruit storage. The fungus produces the mycotoxin patulin, a compound with carcinogenic and neurotoxic properties that is regulated in food products in many countries because of the risk it poses, particularly to young children.