Effects of Break‐Roll Differential on Semolina and Spaghetti Quality

Break‐roll differential provides the shearing action needed to remove bran from the endosperm. The effects of break‐roll differential on semolina and spaghetti quality were investigated using a 25‐quintal (55‐cwt/day) durum pilot‐mill system. Differentials of each break‐roll pair were adjusted to target differentials of 1.5:1, 2.5:1, and 3.5:1 by changing the velocity of the slow roll. Fast rolls were set at a velocity of 350 rpm. Bran specks, ash, and protein increased and semolina brightness (L value) and starch damage decreased with increased break‐roll differential. Semolina yellowness (b value) was greatest with 2.5:1 and least with 1.5:1 differential. Spaghetti brightness (L value) and yellowness (b value) were lower when spaghetti was made from semolina milled at 3.5:1 than from either 2.5:1 or 1.5:1 differential. Strength of dry spaghetti and spaghetti cooking loss and cooked firmness were not affected by break‐roll differential.