Characterization and Rheological Behavior of Dextran from<i> Weissella confusa</i> R003

Abstract

Dextran from Weissella confusa R003 isolated from sugar cane juice was purified and characterized. Dextran synthesis was performed by fermenting W. confusa R003 in MRS medium containing 10% (w/v) sucrose with continuous shaking at 125 rpm and at 30°C. For 24 hours, the 50% efficiency yield was obtained. Dextran in the culture medium was purified by ethanol precipitation. Structural analysis of dextran using 1 H NMR, 13 C NMR, and 2D NMR techniques showed the existence of glucoses with 97.4% α (1→6) linkage in the main chains and 2.6% α (1→3) in branches. The estimation of molecular weight by dynamic light scattering exhibited average molecular weight of 1.0 × 10 4 kDa. At low concentration (2.5% w/v), dextran behaved like liquid structure, while, increasing the concentration (5.0 and 10.0% w/v), it was revealed as viscoelastic behavior. The highest gelling phenomenon was found in the concentration of 10% w/v and at 37°C. Due to its production and properties, it may be suitable for commercial production and application in the field of foods as well as hydrogel.