RVA Characteristics of High Quality Indica Rice during Storage Period

Under different storage conditions, rapid viscosity analysis (RVA) properties of indica rice were studied. Samples of Liangyou 234 type indica with 13.5%, 14.5% and 15.5% moisture content were chosen to store under 15, 20, 25, 30 and 35 ℃ for 720 d, respectively. RVA eigenvalues of the corresponding rice samples were measured by rapid viscosity analyzer every 60 days. The results showed that the storage temperature, storage time and moisture content of rice had very significant effect on RVA eigenvalues (P<0.01), in which the temperature affected mainly. With the extension of storage time, the peak viscosity and breakdown viscosity of rice increased at the early stage of the storage, and decreased in the late storage period. Moreover, the peak viscosity of rice and breakdown viscosity at 30 and 35 ℃ temperature in late apparently decreased faster than the others. Final viscosity, consistence viscosity, setback value, pasting temperature increased during the storage period, in which these three eigenvalues under the high temperature (30 and 35 ℃) storage were greater than the normal temperature and quasi-low temperature storage (25, 20 and 15 ℃). It reflected the quality of rice eating during storage period. With the increasing of storage temperature and the prolonging of storage time, the edible quality of rice decreased significantly, and the deterioration accelerated when the storage temperature exceeded 25 ℃. It could be used as reference conditions for the control of rice storage.