Pasta processing

Drying process begins immediately after the products are shaped to prevent deformation and sticking.

In volumetric feed, a specific volume of semolina is measured by variable speed screws or rotary air-lock valves.

In gravimetric feed, semolina is weighed by a variable speed transport system, which is equipped with a device measuring the flow.

Slanted Surface System: in which the movements of variable speed extraction elements (like screws and bolts) are measured by the electronic devices and are converted to the semolina flow.

The exact amount of water needed for the dough depends on the final shape of the pasta.

[2] The measured amounts of water and semolina are mixed together in pre-mixer to form a crumbly dough.

The traditional type of pre-mixer is a trough with a cylindrical section inside which rotates a mixing shaft with blades.

The shafts run at a low speed (70 rpm) to mix the raw ingredients into a dough.

The extrusion worm kneads and moves the dough forward and presses it through the dies in the head of the extruder.

If the temperature exceeds 50 °C the gluten network would be damaged, which has a negative effect on the quality of pasta.

Since extra heat is generated by pressure and friction, there are water jackets around the cylinder and head.

Otherwise small bubbles will form in the pasta and decreases the mechanical strength which cause breakage from hours to days after drying.

The air also oxidizes the carotenoid or xanthophyll, which results in a white, chalky appearance of the pasta.

Stabilizing helps the remaining moisture to distribute evenly through the pasta and prevents cracking.

[6] The spreader hangs the strands of long pastas on the metal sticks where heated air flow is blown to prepare the product for high temperature.

For the first phase of the finish drying, product goes into a dryer with multi rows of hot water circulation plates.

In the second phase warm air are blown to the product in an isolated multi-tier dryer and removes all the excess moisture.

[2][9] Short pasta pieces fall on the shaker conveyor and powerful hot air is blown to them immediately after the extrusion.

[10] There are two main packaging systems for dried pasta: cellophane bags which are moisture-proof, easy to use in automatic machines, but difficult to stack, and boxes which are easy to stack and print advertising, and protect the fragile pastas.