Figure 4 shows an OCT image sequence for one experiment of rehydration. The cereal pellets are fixed in a cylinder and semi-skimmed milk at room temperature is poured up to 80% of the pellets height. The images are ordered from a-h) according to the rehydration progress during the experiment. At the beginning, no milk is visible along the upper surface of the cereals (Figure 4.a). Then some milk is appearing in the image at the spot indicated by the black arrow (Figure 4.b). From figure 4c to 4h, more and more milk becomes apparent along the upper surface of the cereal pellet, concomitantly to the collapse of the height of the cereal.