The bright yellow colour of durum wheat products is the result of natural carotenoid pigments content and of their oxidative degradation by lipoxygenase (LOX) activity and depends on several factors among which intrinsic quality of semolina and processing conditions are considered to be the most important. The phase mainly responsible for pigment loss is the pasta processing, particularly dough mixing, when a substantial decrease in pigment content occurs, highly correlated with semolina LOX activity. Particularly, fatty acids radicals produced during the intermediate steps of substrate peroxidation are responsible for oxidative degradation of pigments and of thiol groups of peptides and proteins, so promoting a loss of semolina sulphydryl groups. Thus, these reactions can affect other than the colour also the rheological properties of wheat dough. That has made necessary studies of the functional and structural features of the LOX enzyme to utilise in some technological application aimed at improving quality of end products. Furthermore, a reduction of LOX activity during pasta processing is of interest for commercial and nutritional purposes. Since the inhibition of LOX activity by β-carotene has already reported in both animal and plant systems, as well as the antioxidant effects of α-tocopherol and L-ascorbate is known, studies to investigate the LOX inhibition by these compounds in order to prevent the semolina bleaching and to improve pasta quality, are of great technological interest.