Interação entre genótipos de arroz preto e locais de cultivo no perfil de compostos fenólicos e sobre atributos físico-químicos

Abstract

Rice is one of the most produced cereals in the world and the demand for special cultivars, which includes rice for Japanese and Italian cuisine, aromatic rice and pigmented rice, is increasing. The varieties that possess pigmented pericarp have larger amounts of phenolic compounds than the other varieties, with anthocyanins being the main phenolic group of black rice. In addition to genetic factors, environmental factors during the crop development may impact on food quality, and these differences can be used as distinctive characteristics for geographical origin discrimination. Different compounds, separation techniques, and identification techniques as well as several statistical tools can be used to identify compounds or variables that allow discrimination according to the growing location of foods. The objective of this study was to evaluate effects of the growing location on the phenolics profile (including phenolic acids, anthocyanins and other flavonoids) by LC-MS, and the physicochemical attributes of black rice produced in three municipalities of São Paulo (Guaratinguetá, Roseira and Taubaté) and in three municipalities of Rio Grande do Sul (Alegrete, Capão do Leão and Santa Vitória do Palmar). The conditions of Santa Vitória do Palmar, where it is believed that it is mainly due to its latitude and the conditions of the winds during the maturation phase of the rice, favored the occurrence of chalkness in line AE 153045, but did not have implications in genotype IAC 600. The phenolics accumulation, including phenolic acids, flavonoids, and anthocyanins, was modified by the environment, where the tendency was observed for a greater accumulation of these compounds when the grains were produced in SVP. The multivariate statistical analysis made it possible to differentiate the genotypes, with vanillic acid being the main compound responsible for the discrimination. Using the phenolics composition of the free fraction and evaluating each genotype separately, it was possible to discriminate the growing locations, where the principal components explained 98% of the variability in both genotypes. The compounds that had a VIP score higher than 1.0, responsible for the discrimination of the AE 153045 genotype at the different growing locations were hesperetin, vanillic acid, and quercetin-3-O-glucoside, while the compounds responsible for the discrimination of IAC 600 genotype at the different growing locations were quercetin, vanillic acid, quercetin-3-O-glucoside, and p-coumaric acid.