Breads containing,fibers or hydrocolloids were frozen stored as dough (DBs) or semi-baked samples (SBs). Their microstructure (e.g. pore characteristics) was evaluated by image analysis and scanning electron microscopy. The sensory characteristics of "fresh" (one-day stored at ambient conditions) and of semi-baked breads (fully baked the day of observations) were determined by a descriptive analysis. Both composition and storage influenced the mean pore area. However, differences among samples were more evident by determining pore roundness and pore size distribution. Frozen storage favored the appearance of large pores in all samples, especially in the control samples (samples without any enrichment). Control DBs presented a 40% increase in the number of large pores in comparison to the respective number of pores of fresh samples. A decrease in pore roundness was correlated to a structural damage during storage. Pore roundness was correlated to organoleptic attributes such as aroma, adhesiveness and pore size. (C) 2009 Elsevier Ltd. All rights reserved.