The oldest known noodles are believed to have been eaten in China about 4000 years ago. Pasta-like foods have been eaten for centuries, particularly in the Mediterranean and the Middle East. Many of them, however, are not made specifically as the traditional form of pasta, which consists of durum wheat semolina. Traditional spaghetti (and other similar forms, such as ziti and ravioli) became popular in Italy in the 12th century. The food became a popular staple in Italy in the 19th century with the formation of pasta factories, which mass-produced the noodles. It became popular in America in the late 19th century. The name is derived from the Italian word "spago," which means "thin string" or "twine."