흑미강으로부터 유용 폴리페놀 및 플라보노이드의 추출효율 증진을 위한 아임계수의 효과

The extraction of polyphenol and flavonoid from black rice bran was performed by diverse extraction methods using the sugar solution, ethanol, hot water (80°C), and by subcritical water extraction (SWE) method. By SWE under operating conditions of 190°C, 1,300 psi, and 10 min, the maximum yields of total polyphenolic compounds (35.06±1.28 mg quercetin equivalent (QE)/g dried material and flavonoids (7.08±0.31 mg QE/g dried material) could be obtained. These results were over 11.77- and 12.21-fold higher than those of the ethanol extraction, which showed the highest extraction efficiency among tested conventional methods in total polyphenols (2.98±0.74 mg QE/ g dried material) and flavonoids (0.58±0.21 mg QE/g dried material), respectively. Though the highest antioxidant activity (87.14±1.14%) was observed at the dried extract obtained from ethanol method, the relative antioxidant activity per 1 g dried black rice bran by SWE (190°C, 10 min) was over 11.53-fold higher than that by the ethanol extraction.