Impact of visco-metric profile of composite dough matrices on starch digestibility and firming and retrogradation kinetics of breads thereof: Additive and interactive effects of non-wheat flours

• Viscometric profiles of non-wheat flours are lower on pasting compared to wheat flour.
• A cooling stage viscosity peak is formed in buckwheat and teff flours on storage.
• On cooking and cooling, non-additive effects were observed for flour blends viscosity.
• High quality breads met higher/lower viscosities on pasting/gelling of mixed doughs.

The impact of wheat (WT) flour replacement up to 45% (weight basis) by incorporation of ternary blends of teff (T), green pea (GP) and buckwheat (BW) flours on the viscometric pasting and gelling profiles of quaternary blended dough matrices was investigated by applying cooking and cooling cycles to rapid viscoanalyser (RVA) canisters with highly hydrated samples (3.5:25, w:w). Viscometric cooking and cooling parameter trends related to suitable patterns for lower and slower starch hydrolysis, and lower and/or slower firming and starch retrogradation kinetics in blended breads mainly include higher viscosity values for peak viscosity, breakdown on cooking and viscosity of hot (95 °C) paste, but lower viscosity values after gelling (50 °C). These visco-metric requirements for achieving suitable textural and thermal features in blended breads, were met by adding T/GP/BW to replace 22.5% of WT flour in blended dough formulations. Larger WT flour replacement by 37.5% of the ternary mixture T/GP/BW (7.5/15/15) provided hydrated blends with higher values for viscosity of hot (95 °C) paste, and lower viscosity values after gelling (50 °C), in good accordance with poorer formation of rapidly digestible starch and total digestible starch, and more prominent formation of resistant starch and slowly digestible starch in breads, respectively.