According to food experts, a mix of low-protein cake flour (1 part) and all-purpose flour (3 parts) is used by many fine cooks in the United States to substitute 00 flour in a pasta recipe. Some chefs suggest that 100% good ole all purpose flour is an OK stand-in.
00 Flour is sometimes listed in Italian recipes like pizza dough and pasta; it's the most highly refined and is a talcum-powder soft type of flour. Many people believe that this softness also means that the flour is low in protein (like our finely-ground cake and pastry flour). In fact, the protein content of "00" flour can vary quite a bit depending on what kind of wheat it's ground from.
Most "00" flour that we see in the United States is ground from durum wheat and has a mid-range protein content of about 11-12%, similar to all-purpose white flour.
In flour news, thanks to research done by North Carolina State University and the United States’ Army, look for the flour of the future to sport the nutritional value of a handful of blueberries or, potentially, most any other healthy fruit or vegetable.