Identification of molecular driving forces involved in the gelation of konjac glucomannan: Effect of degree of deacetylation on hydrophobic association

Gelation behaviors of konjac glucomannan (KGM) samples with different degree of deacetylation (DD) obtained using a heterogeneous deacetylation method were studied by rheological measurement to probe the effect of degree of deacetylation on hydrophobic association. Compared to polysaccharides whose gelation mechanism is known, we speculate hydrogen bonding and hydrophobic interaction are both presented in KGM gelation and hydrophobic interaction plays a more important role with increasing DD. Hydrophobic characteristic of partially deacetylated KGM (DD was circa 50%) was confirmed using the lyotropic series of salts, suggesting the magnitude of hydrophobic interaction is dependent on DD of KGM. Furthermore, the effect of lyotropic series of salts on gelation behavior of KGM was clarified from a molecular level. (C) 2011 Elsevier Ltd. All rights reserved.