Fig. 4. The hydrodynamic diameters (left) and PDIs (right) of e-TiO2-NPs suspensions (0.5%, 1%, and 1.5% w/w) without or with the presence of food matrix during each digestion phase in vitro. The lower-case (a–d) and capital (A–D) letters indicate significant differences between the digestive steps in the absence and presence of the food matrix (P < 0.05). * indicates significant differences between the absence and presence of the food matrix for each phase of digestion (*P < 0.05 and **P < 0.01).
