Baking properties and resistant starch contents of gluten-free buckwheat-rice bread formulations

Celiac disease drastically limits the dietary options available to those afflicted and eliminates a major food staple, bread. Buckwheat, a gluten-free pseudocereal offers an alternative that can offer additional health benefits compared to rice flour alone. The aims of this study were (1) to develop a base buckwheat-rice flour containing bread formulation, and (2) to determine effects on baked properties and resistant starch contents of breads made with varying levels of canola oil [(4% or 8% flour weight basis (fwb)], egg white solids (5% or 10% fwb), batter consistency (100 B.U. or 125 B.U.), and mixing time (5 min, 10 min, or 15 min). Breads were baked, stored at ambient temperature under sealed conditions, and evaluated for appearance, specific volume, and hardness on day three, and for resistant starch content and moisture on day seven. A lower batter consistency decreased the appearance of cracking on the baked crust surface with more open cell structure in the crumb. Lower consistency batters produced breads with higher specific volumes (1.84 to 2.58 cm3/g) compared to those of higher consistency batters (1.69 to 2.27 cm3/g). Crumb hardness was decreased to below 100 N for all breads made from lower consistency batters. For the same batter consistency level, variation in mixing time produced some significant differences in specific volume and hardness of bread loaves. The resistant starch contents of breads after storage for 7 days were not affected by differences in canola oil or egg white solids contents, but were significantly different (p<0.05) between 5% egg/4% oil and 5% egg/8% oil (fwb) counterpart samples made from batters with different consistencies.