Levels of curcuminoid and essential oil compositions in turmerics (Curcuma longa L.) grown in Korea

Levels of curcuminoids and essential oil compositions from eighteen turmerics (Curcuma longa L.) grown in Jeju were analyzed. 0.5 g of turmeric samples was extracted with 20 mL of methanol for 7 h by shaking and was ultra-sonicated for 30 min. The extracts were analyzed by high-pressure liquid chromatography-diode array detector using Brownlee SPP C18 column (4.6 × 100 mm, 2.7 µm) after filtration. Curcumin (CUR), demethoxycurcumin (DEM), and bisdemethoxycurcumin (BIS) were monitored at the wavelength of 420 nm. Total curcuminoids in turmerics ranged from 53.9 ± 1.0 to 5396.0 ± 101.8 µg/g dry turmeric weight. In decreasing order, curcuminoids found were CUR (4669.7 µg/g) > DEM (565.3 µg/g) > BIS (160.9 µg/g). K145023 variety contains the highest amount of curcuminoids and variety number 10 contains the least amount. Essential oils were extracted with steam distillation method and analyzed with GC–MS. The major components of turmeric oil were α-zingiberene (27.70–36.75 %), aromatic-turmerone (19.54–32.24 %), β-sesquiphellandrene (13.14–18.23 %), α-turmerone (3.72–6.50 %), β-turmerone (2.86–5.60 %), and β-bisabolene (2.50–3.46 %).