Durum wheat milling and pasta

Pasta, in its fresh and dry version, is a very popular food consumed worldwide. Durum wheat has been traditionally used especially for the dry pasta and it is the raw material of choice because of the rheological properties of its proteins and its pigment content. In some countries such as Italy, France or Greece, durum wheat semolina is the only raw material permitted for pasta production by national laws. Special pasta is also produced by using other cereals or by adding a great variety of other ingredients such as eggs, vegetables, legumes, gluten, milk proteins, vitamins, and minerals. Pasta products can therefore have different compositions, colors, and shapes but they all share a basic technology that involves the preparation of a dough made by mixing semolina/flour with water, which is then processed mainly by extrusion to obtain the required shape (spaghetti, macaroni, stars, etc.). The extruded pasta can then be dried under controlled conditions of moisture and temperature to obtain the final product which can be stored for years. For several centuries, pasta production was home-based and only during the nineteen century, it became an industry thanks to the invention of the steam engine and hydraulic presses followed by the development of artificial instead of natural drying. In this chapter, the focus will be on durum wheat pasta. The chemical and technological qualities of the raw material which are appreciated by pasta makers will be discussed, as well as durum wheat milling to produce semolina, a coarse and grainy flour whose physical characteristics make it suitable to stand kneading and extrusion, and for maintaining its shape during drying and cooking. Semolina characteristics will be discussed together with the pasta manufacturing process. The cooking and nutritional qualities of durum wheat dry pasta and its environmental performance will also be reported.