Comparison between varieties of rice (Oryza sativa L.) produced in Portugal – mineral and quality analysis

Rice (Oryza sativa L.) is considered one of the most consumed cereals worldwide. In fact, for many countries, rice is considered a staple food crop. In this context, in Portugal, Ariete and Ceres are well known for rice varieties that produce grains with a high quality, yet little is known about their nutrient accumulation. In this context, this study aimed to characterize and compare both varieties produced in the central region of Portugal (Ribatejo). Whole and white rice grains, as well as the respective flours, were analyzed in order to quantify the mineral content of macro and microelements (Mo, Ca, K, P and S). Mo content varied significantly between 4.7 - 11.2 mg.kg^-1 in the whole flour of Ceres and Ariete, respectively, while P content was only detected in the flour of the Ariete variety. For both varieties, there were no significant differences in their content of other elements. Moreover, total ash content in the refined flour showed significant differences in both varieties. Quality parameters, such as density of the grains and colorimetric indexes (L, a* and b*), in whole and white grain, were also considered, with density values varying between 1301 – 1651 kg.m³ (in the Ariete variety) and 1492 - 1573 kg.m³ (in the Ceres variety). It was concluded that, in spite of the differences in both varieties, minerals contents combined with the quality parameters showed the common characteristics required for a high industrial and gastronomic potential.