The Mechanism of Development of Viscosity in Yam (Dioscorea opposita THUNB) Mannan

Abstract

This study investigated the mechanism of development of viscosity in mannan, the primary component of yam mucilage. The viscosity of the viscous polysaccharide fractions was lower for mannan obtained from the Nagaimo variety, characterized by the large number of side chains, than for the Tsukuneimo and Ichoimo varieties. Mannan aggregates due to a hydrophobic interaction which in turn results in viscosity. The number of side chains in mannan molecules has a major effect on aggregation and viscosity. A mutual relationship exists between viscosity of viscous polysaccharides of Tsukuneimo, Ichoimo and Nagaimo varieties and mannan structure.