Investigation of the structure-forming role of dietary fibre components in gluten-free cereal- and pseudocereal-based food matrices

The aim of this work was to investigate the structure-forming ability of cereal β-glucan (BG) and arabinoxylan (AX) in gluten-free (GF) dough and slurry matrices. 2, 5 or 8%, w/w BG was dosed to white millet and buckwheat flours and its effect on the mixing and pasting properties was examined. Furthermore, AX “incorporation” into dough structure and possible interaction with millet and buckwheat proteins were investigated by using reduction and subsequent re-oxidation based on our previous work.

BG addition increased consistency and changed mixing properties in both millet and buckwheat doughs by forming viscous gel and aggregates. However, its impact on the pasting properties of the two types of GF flours differed in tendency. Similarly, a different behaviour of millet and buckwheat matrices was found in case of AX incorporation, explained by their distinct macromolecular (especially protein) composition. SDS-PAGE results referred to interactions between AX molecules and non-gluten proteins, however the changes in free ferulic acid contents did not confirm this. Although, white flours of millet and buckwheat are simpler matrices than wholemeals, they might be still too complex to examine the effect of a specific component, especially in a redox system. Thus, development of model gluten-free dough systems is a further goal of this work.

Research works focusing on AX or BG functionality in gluten-free matrices are rare. The current work might contribute to a better understanding of dietary fibre functionality in dough systems with non-gluten proteins, as well as to develop healthier gluten-free products of higher fibre content.