Abstract:Black rice embryo is rich in nutrients. However， reports on its separation and preparation are scarce. In this study， unpolished black rice was used as the raw material to establish a preparation process for defatted black rice embryo （DBRE） based on the solvent density flotation method. By utilizing the difference in relative density between bran and embryo， low-polarity lipophilic solvents were employed to achieve branembryo separation， defatting， and nutrient enrichment. The results showed that dichloromethane， dichloroethane， chloroform， and their combined solvents could all realize flotation separation of bran and embryo. The yield of DBRE was 5.63%-11.33%， the yield of defatted black rice bran was 67.88%-80.45%， and the yield of rice bran oil was 12.17%-15.13%. The overall recovery rate ranged from 92.87% to 99.51%， and the solvent recovery rate ranged from 68.33% to 87.00%. The prepared DBRE exhibited a regular and uniform morphology， with a lipid content of 1.69%-2.02% and lipase activity of 5.50-6.19 mg/g， both significantly lower than those of black rice and black rice bran. No obvious solvent residue was detected， and the acid value showed no significant increase after 60 days of storage at room temperature. The anthocyanin content of DBRE was 4.03-6.58 mg/g， the γ-aminobutyric acid content was 21.02-28.37 mg/100 g， and the total phenolic content was 9.60-11.89 mg GAE/g DW， all significantly higher than those in black rice. This process is simple，and the resulting product exhibits high stability and nutritional value. The study is of positive significance for promoting the deep processing and high-value utilization of black rice.