Physicochemical Properties and Antioxidant Activities of Steam-Dried Allium hookeri Root

This study was carried out to investigate the effect of steam-drying method on physicochemical properties and antioxidant activities of Alliun hookeri root (AHR). Moisture, crude protein, crude fat, and crude ash contents of raw and steam-dried AHRs were 10.91~14.15%, 11.14~13.49%, 0.83~3.02%, and 7.55~8.98%, respectively. Sulfur contents of steam-dried AHRs were 2.0 and 2.2 times lower than that of raw AHR (0.51%), respectively. pH and total sugar contents of AHRs were reduced by steam-drying, whereas titrate acidity and browning intensity were increased. The L and b values of AHRs in Hunter's value were also reduced, but a value was increased by steam-drying. Among hot water extracts from raw and steam-dried AHRs, four times steam-drying showed the lowest $EC_{50}$ values (0.44, 9.01, and 0.48 mg/mL, respectively) in DPPH radical assay, ABTS radical assay, and reducing power, whereas four times steam-drying had the highest total phenolic content ($34.47{\mu}g/mg$) and browning intensity (2.05 and 0.20 at 280 and 420 nm, respectively). The antioxidant activities of hot water extracts from raw and steam-dried AHRs were closely correlated with their total phenolic contents and browning intensity, showing coefficient of determination ($R^2$) values higher than 0.87. From the results, we suggest that steam-drying method could be used as an effective process for increasing the antioxidant activity of AHR.

증포 처리한 삼채 뿌리의 이화학적 특성 및 항산화 활성

증포 처리가 삼채 뿌리의 품질 특성 및 항산화 활성에 미치는 영향을 조사하였다. 증포 처리한 삼채 뿌리는 생 삼채 뿌리보다 황 함량이 각각 2.0배와 2.1배 감소하였다. pH와 총당은 증포 처리에 의해 감소하였으나 적정산도와 갈변도는 증가하였다. 색도의 경우 L과 b 값은 감소하였으나 a 값은 증가하였다. 열수 추출물의 항산화 활성은 증포 4회가 DPPH radical assay, ABTS radical assay 및 reducing power에서 $EC_{50}$ 값이 각각 0.44 mg/mL, 9.01 mg/mL 및 0.48 mg/mL로 가장 낮게 나타났으나 TPC($34.47{\mu}g/mg$)와 갈변도(2.05 at 280 nm와 0.20 at 420 nm)는 가장 높게 나타났다. 이들 성분과 각 항산화 활성에 대한 $EC_{50}$ 값의 $R^2$는 0.87 이상의 높은 값을 나타내었다. 결과적으로 증포 처리는 삼채 뿌리의 항산화 활성을 증가시키는 데 효과적인 가공 방법으로 판단된다.