Effects of break-roll differential on semolina and spaghetti quality

Abstract

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.