Investigators, who seized the entire supply of mozzarella from the Frosinone store, were trying to determine the cause of the discoloration and the origin of the cheese, Italian news agency ANSA reported.
In March, teachers at a Genoa elementary school stopped lunch and contacted inspectors after mozzarella turned blue. Authorities concluded the discoloration was caused by yeast and the cheese posed no health risk.
In 2010, ANSA said, German-made mozzarella cheeses that turned an inky blue color after being opened were found in 14 European countries, leading to a widespread scare, after being discovered in Turin.
In response, the European Union stopped the mozzarella producer, Milchwerk Jaeger, from doing business for one month until the EU believed the problem had been resolved.
Italian farmers protested, saying the scare showed products typically made in Italy had been made outside the country according to lower standards. Foreign makers give the products Italian-sounding names to try to make customers believe they're made in Italy, the farmers said.