Physico-chemical characterization of spruce galactoglucomannan solutions: Stability, surface activity and rheology

The physico-chemical properties of the industrially-recovered spruce galactoglucomannans were studied. The solubility after filtration was determined by GC. Short- and long-time stability of galactoglucomannan water solutions of different concentrations was investigated with a light-scattering-based Turbiscan instrument. The effects of filtration, NaCl addition, heat treatment and deacetylation on stability were studied. During the measurements, commercial Konjac glucomannan was studied for the sake of comparison. The surface activity and apparent viscosity of galactoglucomannan solutions were also studied. Additionally, the rheological properties of the solutions were investigated. Both storage and loss moduli increased at concentrations higher than 1%. Elastic behavior was displayed throughout the frequency, at high concentration. Concentration regimes with three regions were applied to explain the solution properties.