Italian durum wheat grown in Sicily was studied for its breadmaking quality based on protein content and composition. Gluten properties were assessed using various tests, showing that certain protein types affect bread quality differently. Cultivars with specific gluten subunits had better loaf volumes, indicating the importance of protein composition in determining gluten viscoelasticity. Low-molecular-weight glutenin subunits were found to directly impact gluten quality, while high-molecular-weight subunits at the Glu-B1 locus had varying effects on breadmaking quality. The study highlights the significance of protein composition in durum wheat for producing high-quality bread.