Effect of drying air temperature and storage on industrial and chemical quality of rice grains

Abstract

The drying air temperature and storage time can change the milling yield and chemical composition of rice grains. Therefore, the objective was to verify the industrial quality and chemical composition of rice grains, white and integral subgroups, in response to drying air temperature and storage time. For such, the rice grains were subjected to drying in a column dryer with a grain capacity of 1 m3, using 55 and 65 °C drying air temperatures. After, they were stored in PP Woven Bags under environmental conditions for 240 days. After drying and every 60 days the milling was performed, aiming to evaluate the industrial quality and chemical composition of the grains. The whole grains yield was negatively affected by the increase in drying air temperature for both subgroups. The increase in the drying air temperature led to a reduction in the lipid content and an increase in the ash content for grains of white subgroup. The storage time promoted an increase in the whole grains yield in the white subgroup when the grains were dried with the highest drying air temperature. The lipids and proteins contents decreased, while the fibers and ash contents increased during storage for the white subgroup grains. The chemical composition of grains from the brown subgroup did not change during storage, regardless of drying air temperature.