Effect of Process Variables on Spaghetti Quality

Five process variables (water absorption, barrel temperature, screw speed, mixing time, and water temperature) were investigated to determine their effects on pasta quality. Response surface methodology (RSM) was used to identify the process variables levels yielding optimum pasta color and cooking characteristics. Water absorption and barrel temperature had the greatest effect on the response variables studied (pasta brightness, yellowness, firmness, cooked weight, and cooking loss). Screw speed was a significant factor in the response surface models for all the pasta quality parameters, except cooking loss. Mixing time had a significant effect on pasta color and firmness, while water temperature affected only firmness. Contour plots showed that spaghetti brightness and firmness improved at lower water absorption (30.5-31%) and lower barrel temperature (35-45°C) and at intermediate screw speed (25 rpm). Spaghetti yellowness showed similar trend, except that it increased at higher barrel temperature. Cooking loss appeared to be minimized at water absorptions and barrel temperatures ranging from 31.5 to 32% and 45 to 50°C, respectively.