Development of fibre-enriched wheat breads: impact of recovered agroindustrial by-products on physicochemical properties of dough and bread characteristics

Dietary fibre is easily available in plant foods. However, western diet frequently does not meet recommended levels. Fibre supplementation of bread is an opportunity due to its daily consumption. In this work, fibre-enriched extracts were recovered from elderberry (EE), orange (OE), pomegranate (PE), and spent yeast (YE), and their fibre composition was characterized. The impact of wheat flour replacement by different fibre extract amounts on dough properties indicates that (1) optimum water absorption increased with higher concentrations of OE, PE, and YE; (2) development time for EE, PE, and YE was shortened, while the opposite was observed for OE; (3) the onset of starch gelatinization and maximum tan delta increased significantly with 36% EE and 4% PE; (4) protein structure, observed with confocal laser scanning microscopy, was modified by addition of extracts; and (5) maximum and final dough height decreased significantly, except for 4% EE. Wheat flour replacement also had an impact on bread parameters, since (1) volume and specific volume decreased at the highest concentrations in every extract; (2) significant changes were observed in crumb texture and structure, at higher extract concentrations. Multivariate PLS regression highlights the relationships between dough and bread data.