RELATIONSHIP BETWEEN MACROSCOPIC AND MICROSCOPIC VISCOSITIES IN STARCH GELS

摘要

We investigated the relationship between the macroscopic viscosity (eta(N)), determined by creep measurement, and the microscopic viscosity, estimated by rotational correlation time (tau(c)) of spin label determined by ESR method, for wheat and potato starch gels. Both eta(N) and tau(c) of wheat starch gel increased linearly with an increase of starch concentration. Both eta(N) and tau(c) of potato starch gel increased exponentially with an increase of starch concentration. The tau(c) of wheat starch gel related linearly to the eta(N) of the gel at 30, 40 and 50 degrees C. For potato starch gels, the tau(c) also related significantly to the eta(N) at 30, 40 and 50 degrees C. The tau(c) of free BrAcTEMPO was much smaller than that of spin-labeled AcTEMPO in wheat starch gel. It is concluded that the change in microscopic viscosity of starch gels agrees with their change in macroscopic viscosity. [References: 13]