Depolymerization of double-stranded xanthan by acid hydrolysis: characterization of partially degraded double strands and single-stranded oligomers released from the ordered structures

Double-stranded xanthan was depolymerized by partial acid hydrolysis to produce samples where M w ranged from 6×10 6 to 7×10 4 . These were characterized with respect to chemical composition in the side chains, molecular weight, molecular weight distribution, intrinsic viscosity, and conformation (optical rotation). Additional information about molecular size and conformation was obtained by electron microscopy. For each sample a fraction consisting of depolymerized, double-stranded species could be obtained. Their conformational properties were largely analogous to undegraded xanthan, despite the reduced M w and the changes in the side chains