Microwave assisted dissolution of β-glucan in water — implications for the characterisation of this polymer

Microwave heating in a high-pressure vessel was used to assist the dissolution of a high molecular weight β-glucan in water. These samples could not be fully dispersed by heating and stirring at 80°C. This was evident from the detection of large aggregates by light scattering and from low sample recovery after filtration. When the pre-hydrated solution was heated in a microwave at a temperature lower than 90°C, aggregation could not be effectively reduced within 30 min. However, when the solutions were heated to 100, 110 and 121°C and held at these temperatures for 4–10 min, good dispersability was achieved without degradation. Sample recovery increased from 75±5% to 98±2%. Longer time at high temperatures (110 and 121°C) induced polymer degradation.