Remarkable differences could be seen between the microstructures of non-fermented (Fig. 5A) and fermented (Fig. 5B) gruels observed through SEM.As can be seen inFig. 5A, the gruelswere thoroughly gelatinized before the inoculation step and no grains of starch could be seen. Nonfermented gruel was characterized by a coarser and irregular structure with large and heterogeneous fragments while fermented gruels made more homogeneous and smoother structure with smaller fragments.