Study on shear rheological properties of Konjac glucomannan and Agar blends

Rheometer was used to determine rheological properties of Konjac glucomannan and Agar ( KGM/Agar) under various conditions of concentration, heating time and temperature. The results showed that the viscous coefficient ( k) of KGM/Agar blend system increased with the the increase concentration and the heating time prolong.While the temperature was in the range of 30 ~ 60 ℃, the viscous coefficient ( k) increased at first then decreased and increased again as wave-like changes, with increasing temperature. The results of viscosity coefficient and flow index showed that the optimal parameters was the mass concentration of KGM/Agar blend 1.2%, swelling temperature of 40 ℃, swelling time 120 min. The rheological properties of KGM/Agar blend system could be fitted by power-law model and the change tendencies of viscosity factor ( k) and flow index ( n) correlated with concentration, heating time and temperature were also obtained.The curves could be fitted by power and polynomial curve and could provide a reliable foundation for proper applications of KGM/Agar in the food industry and its quality evaluation.