2.5. Pasta Making

Spaghetti was manufactured through an experimental pasta-making semi-industrial plant (NAMAD, Roma, Italy) composed of a press and a dryer, following AACC Method 66-41.01 [43]. The press, with a working capacity of 5–20 kg, was equipped with: (1) a vacuum mixing and extruding system composed of a screw-barrel that pushes the product, (2) a die that restricts the flow-out of the dough, and (3) a water-cooling jacket of the barrel and the extrusion head to reduce heat and to maintain a constant extrusion temperature lower than 50 °C. Each series of spaghetti was dried at a temperature lower than 80 °C using temperature/humidity equilibrium curves. An example of the adopted drying diagram is shown in Figure 1.

Pasta drying diagram: relative humidity and temperature vs. time.

The dryer was equipped with: (a) a ventilator unit to ensure uniform temperature and ventilation in all parts of the apparatus; (b) a moisture regulation and control unit; and (c) a regulation and program unit equipped with a computer and dedicated software developed on the LabView platform by DRD AUTOMAZIONE srl (San Giovanni in Galdo, Campobasso, Italy).

Spaghetti was produced using the operative parameters reported in Table 2.

Operative parameters for pasta production.

EVP15-2(T), pasta from blend 85% Semolina 2 and 15% EVP extruded with Teflon-coated die; EVP15-2(B), pasta from blend 85% Semolina 2 and 15% EVP extruded with bronze die; EVF10, pasta from blend 90% Semolina 1 and 10% EVF extruded with Teflon-coated die; PS, pasta from Semolina 2 extruded with Teflon-coated die; PWS, pasta from Wholegrain semolina extruded with Teflon-coated die.

Bronze (brass/bronze alloy) dies with Teflon and bronze inserts were used for producing spaghetti with a mean diameter of 1.7 and 1.8, respectively. Extrusion occurred at 30 °C ± 2. EVF-enriched pasta, pasta 100% semolina-2, and 100% wholegrain semolina were both made with a Teflon-coated die. Pasta enriched with EVP was made using bronze and Teflon dies, indicated with EVP15-2(B) and EVP15-2(T), respectively.