Title: Physico-chemical aspects of leavened gluten-free breads Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2007
Publication Date: N/A
Technical Abstract: For wheat breads, there is wide consensus that gluten is the relevant component in determining breadmaking quality. For gluten-free bread, intact and damaged starch, hemicelluloses, added hydrocolloids, proteins and lipids all have been shown to have some impact. However, their individual contribution and interactions in various formulations have not been well understood. The present study focuses on starch bread as a simplified model, and on sorghum bread as an example for a complex gluten-free system. The effects of xanthan gum, hydroxypropyl methylcellulose (HPMC) and water level on starch bread are described. Higher loaf volumes can be reached when using HPMC rather than xanthan gum due to the surface activity of HPMC, which acts to stabilize foam. The role of proteins in sorghum bread was evaluated and we found that total degradation by protease as well as the formation of aggregated networks upon baking were undesirable. This suggests that the role of proteins in gluten-free bread is quite different from wheat bread. Two directions to improve protein functionality are possible: staying with batter systems similar to rye dough, or creating an artificial viscoelastic dough. The conditions for the latter, like mixing of maize prolamins at increased temperature, are described and chances for an improved gluten-free bread from viscoelastic dough evaluated. Overall, creation of elastic protein networks is not as important in gluten-free bread as sometimes supposed.