Effects of resting on drying and storage period on the metabolic defects and industrial performance of polished and parboiled rice

The consumption of parboiled rice in Brazil has shown great increase in the last decades, what is demanding knowledge to analyze its performance. The objective of this work is to evaluate the effect of storing period in industrial performance and incidence of defects in processed grains as conventional and parboiled rice. Rice grains were stored in 50 kg cotton bags with 13 % moisture for 12 months, with technical and operational control. Moisture, industrial performance and incidence of defects were analyzed quarterly. It was observed that: a) there is a direct relation between resting time before drying and storing period, with the incidence of defects on rice grains in both production processes, conventional polished white rice and parboiled rice; b) the increase in the storing period has smaller effect on yield and industrial performance than in the incidence of metabolic defects; c) as the length of storage period increases, the parboiling process increases more the percentages of whole grains and the occurrence of metabolic defects than the conventional polished white rice process.