Rheology of rice-flour pastes: effect of variety, concentration, and temperature and time of cooking.

Cookedpastes of rice flour showed time-dependent shear thinning (thixotropy).
Yield stresses were observed at high concentrations and high pasting temperatures.
The Herschel-Bulkley power law equution could be used with certain
limitations to characterize the flow behaviour of the pastes. At low pasting
temperatures (hO", 75"C), apparent viscosity increased with increasing concentration
and time of cooking, and was higher for low-amylose than for highamylose
rice. But when cooked at 95"C, two distinct patterns were seen. At low
concentrations, apparent viscosity again increased with increasing time of cooking
und was higher for low-amylose than for high-amylose rice. But at concentrations
above 7%, the pattern was totally reversed, viz., viscosity decreased
with time of cooking and wus higher for high-amylose rice