Propriedades físicas de grãos de arroz Moti em casca com variação do teor de água

Abstract

The knowledge of the physical properties of agricultural products is of great relevance in all post-harvest stages, as well as for the sizing and operation of equipment for major operations. Moti gome rice, produced in highlands in Brazil, requires a lot of information, given that its cultivation is predominant in Asia and in irrigated systems. Thus, the aim of this study was to determine the physical properties of Moti rice grains in husk at different moisture levels and evaluate the dependence between these variables. The determined properties were: 1,000 grain weight, bulk and real density, porosity, grain size and shape. Five moisture levels of interest were defined: 10.00, 12.30, 13.80, 18.60, and 22.00 % w.b. The results indicated that the magnitude of moisture content influences the physical properties of Moti rice grains, being directly proportional. For the evaluated moisture range, values ranged from 506.73 to 519.06 kg m-3 for bulk density, 987.00 to 1,170.00 kg m-3 for real density, and 48.65% to 55.80% for porosity. Regarding the size and shape characteristics of the grain, only the average dimension (width) and sphericity showed dependence on the variation of moisture content. Linear regression models fitted the experimental data of 1,000 grain weight and bulk density, while for sphericity and real density, the best fit was obtained through second-degree polynomial equations.