Physicochemical, nutritional, and functional characterization of gluten-free ingredients and their impact on the bread texture

Despite the commercial availability of gluten-free (GF) products, numerous nutritional, sensory, and textural limitations have been brought to the attention of the baking industries. This study aimed at the characterization of four GF flours (pregelatinized rice, pearl millet, common buckwheat, and soy protein isolate) for their nutritional and functional properties. Protein and starch were the major components in soy protein isolate and pregelatinized rice, respectively, whereas buckwheat and millet contained the highest amount of dietary fiber. Free phenolic compounds and antioxidant activity were at the highest levels in buckwheat flour followed by soy protein isolate. Likewise, all investigated ingredients varied greatly in their physicochemical properties. Based on single-ingredient baked-model, the effect on the texture and volumetric profiles of bread was reported, distinguishing GF ingredients in four different clusters with different characteristics. Accordingly, the four GF ingredients were combined to create a composite GF bread with acceptable textural properties approaching to those of a typical wheat bread. These findings might be regarded as a basis to design further innovative recipes and combinations using these raw GF ingredients.