The use of red lentil flour in bakery products: how do particle size and substitution level affect rheological properties of wheat bread dough?

Inclusion of pulses flour in bread formulation has important nutritional effects but its successful implementation is challenging and requires a good understanding of the effect of flour functionality, granulometry and substitution level on bread quality. Accordingly, this work studied red lentil flour and its dimensional fractions (coarse, medium, fine, extra-fine), considering compositional, morphological, functional, and thermal properties. Additionally, the effect of substituting wheat flour with lentil flour and its fractions at different levels (0, 10, 15, 20, 25 and 30% [w/w] flour basis) on dough rheology was studied using a Mixolab device, to predict bread quality. Although flour’s properties were significantly affected by particle size, multivariate statistics suggested that the substitution level was the major factor affecting rheological properties of doughs made with blends of wheat and lentil flours. A 10% substitution level of wheat flour by lentil flour provides optimum rheological properties regardless of lentil flour particle size, while at higher substitution level (15-30%), a coarse fraction can provide higher performance compared to unfractionated flour and finer fractions. The results of this study pose an important base to intelligently develop wheat-lentil bread applications in the future.