Blue cheese of blue veins. The distinctive flavor and aroma of blue cheese arises from methyl ketones (including 2-pentanone, 2-heptanone, and 2-nonanone) which are a metabolic product of "Penicillium roqueforti". These compounds are not formed in other types of cheese fermented by bacterial acidification alone. In the European Union, many blue cheeses, such as Cabrales, Danablu, Gorgonzola, Roquefort and Blue Stilton, carry a protected designation of origin, meaning they can bear the name only if they have been made in a particular region. Similarly, individual countries have protections of their own such as France's Appellation d'Origine Contrôlée and Italy's Denominazione di Origine
Romano cheese Romano cheese Romano cheese is an American and Canadian term for a class of cheeses. They are hard, salty cheeses, suitable primarily for grating, similar to Pecorino Romano from which the name is derived. In spite of the name, it should not be confused with genuine Pecorino Romano which is an Italian product recognized and protected by the laws of the European Community, though United States law allows Romano produced entirely from sheep’s milk to be called "Pecorino Romano". Per U.S. Food and Drug Administration regulations, Romano cheese can be made from cow, goat, and/or sheep's milk. It must contain