Abstract
A highly viscous exudate was prepared by stirring “Mekabu” (sporophyll of Undone pinnatifida)after soaking in hot water. The viscosity of exudates prepared under different conditions (temperature and NaCl addition) was measured with an E type viscometer. To define the factor of change in its viscosity, the content and viscosity of dry matter in the viscous exudate were measured.
The influence of temperature and NaCl addition on the viscosity of sodium alginate extracted from “Mekabu” was investigated. The viscosity of the viscous exudate prepared at 20°C was 4.74cP, and it increased to 21.76 cP at 8°C. The viscosity of the viscous exudate was correlated with the content and viscosity of dry matter. The amount of the component which can maintain a high degree of viscosity at high temperature increased when the temperature of the preparation was raised.
NaCl addition decreased the viscosity of the viscous exudate during soaking and stirring, although it had had little influence on the content and viscosity of dry matter after dialysis. The viscosity of sodium alginate declined with NaCl addition. The decreased viscosity of the exudate was mainly responsible for the change in structure of dissolved polyelectrolytes from NaCl addition.
