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 alpha-(1 -> 6)-linked linear backbone and 3% alpha-(1 -> 3) branches, and had a molar mass of 3.3 x 10(6) g/mol. In situ production resulted in 3.5% dextran (DW) which significantly enhanced the dough extensional properties, increased the bread specific volume (similar to 13%) and decreased crumb firmness (similar to 43%), moisture loss (similar to 15%) and staling rate (similar to 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 (similar to 30%) and antioxidant activity. It also markedly lowered the bread predicted glycemic index and improved in vitro protein digestibility.