米糠乙醇萃取液（E）在溫度45°C及壓力30、25、20和15 MPa下，以超臨界CO2流體區分為R、F1、F2和F3 等區分物。本研究評估各區分物中抗氧化成分（米糠醇、阿魏酸及總酚）含量、抗氧化能力及其相關性。結果顯示，F3區分物中米糠醇、阿魏酸和總酚含量最高，抗氧化能力之DPPH與ABTS+自由基清除能力亦是F高於R。總酚、米糠醇和阿魏酸之含量與抗氧化能力呈顯著正相關。由線性結構模式分析顯示，雖然抗氧化成分彼此之間的相關性很高，但兩種自由基的清除活性主要是與總酚有關。

Ethanol extract (E) of rice bran was fractionated by supercritical CO2 fluid system into four fractions (R, F1, F2, and F3) at 45oC and pressures of 30, 25, 20, and 15 MPa, respectively. This study aimed to evaluate the distribution of antioxidant compounds (y-oryzanol, ferulic acid, and phenolic compounds) and antioxidant activities of supercritical CO2 fractions. Results showed that the highest amounts of y-oryzanol, ferulic acid and phenolic compounds were in F3 fractions. The DPPH and ABTS radicals scavenging activities in F fractions are higher than in R fraction. The contents of phenolic compounds, y-oryzanol and ferulic acid in fractions were significantly positive correlated with the antioxidant capacities. Linear structural models analysis showed that although the correlation between antioxidant components is high, the scavenging activities of both free radicals mainly related to phenolic compounds.