Agronomic Characteristics, Anthocyanin Content, and Antioxidant Activity of Anthocynins Extracted from the Seeds of Black Rice Accessions

The objectives of this study were to investigate the morphological characteristics, grain yield, and anthocyanin content of 36 black rice accessions that were collected from different locations in Vietnam. The results showed that the black rice accessions varied in growth duration (130 to 150 days), plant height (91.5 to 143.6 cm), morphological characteristics, and yield components. Grain yield of the black rice accessions ranged from 2.8 to 8.7 tons ha^-1. The black rice accessions were classified into four groups based on their anthocyanin content: group I > 0.1% anthocyanin, group II 0.05%-0.1%, group III 0.001%-0.05%, and group IV < 0.001%. BR7 had the highest anthocyanin content (0.1438%), followed by BR5 (0.1317%). Anthocyanins with the strongest antioxidant activities were extracted from BR8, BR35, BR6, BR27, BR30, BR32, BR18, BR17, BR19, and BR1 with IC₅₀ values less than 2 µg mL^-1. Seven promising black rice accessions, namely BR1, BR14, BR17, BR25, BR30, BR34, and BR35, were selected for further research based on their high anthocyanin contents, and good grain yield and yield components.