Dextran produced in situ as a tool to improve the quality of wheat-faba bean composite bread

Impact of broad beans addition on rheological and thermal properties of wheat flour based sourdoughs

Broad bean flour is a valuable source of proteins and micronutrients and can efficiently balance the nutritional value of wheat flour. The aim of the study was to assess the impact of wheat flour substitution by native and germinated broad beans on the water related, thermal and rheological properties of the composite flours and sourdoughs. Regardless of the investigated flour, temperature increase resulted in significant decrease of water soluble index. Addition of broad bean to wheat flour affected the swelling power. Differential scanning calorimetry measurements on flours indicated two peaks at ∼70 °C assigned to starch gelatinization, and ∼100 °C attributed to amylose-lipids complexes disruption. The same thermal dependent events were highlighted through the rheometric temperature ramp test. Sourdoughs were further obtained out of the composite flours and dynamic rheometric analysis showed that fermentation improved flow resistance. Wheat substitution by broad bean flour increased sourdoughs consistency due to the higher protein content.

Influence of dextran synthesized in situ on the rheological, technological and nutritional properties of whole grain pearl millet bread

The effect of dextran produced in situ by Weissella confusa on the structure and nutrition quality of whole grain pearl millet bread containing 50% of wheat flour was investigated. NMR spectroscopy analysis indicated that the dextran formed by the strain consisted of a α-(1 → 6)-linked linear backbone and 3% α-(1 → 3) branches, and had a molar mass of 3.3 × 10⁶ g/mol. In situ production resulted in 3.5% dextran (DW) which significantly enhanced the dough extensional properties, increased the bread specific volume (∼13%) and decreased crumb firmness (∼43%), moisture loss (∼15%) and staling rate (∼10%), compared to the control millet bread. DSC analysis showed that amylopectin recrystallization was significantly reduced in the bread containing dextran. In situ dextran production altered the nutritional value of millet, leading to increased free phenolic content (∼30%) and antioxidant activity. It also markedly lowered the bread predicted glycemic index and improved in vitro protein digestibility.