Starch granules in pasta are also embedded in protein matrix, which is attributed to the
greater protein content of durum wheat than that of other wheat species. The protein matrix
forms a barrier and prevents the diffusion of water into the center of the pasta (Cunin et al
1995). As the result, the starch granules in the center of the pasta are not fully gelatinized
during boiling and are less susceptible to amylase hydrolysis than the starch in white bread
(Figure 7A) (Granfeldt et al 1991, Barkeling et al 1995). The digestibility of starch in pasta
increases when protein is removed using proteases (Fardet et al 1998, Zhang and Hamaker
1998)