Rhizome Sample

Materials used in this research are rhizomes sample, there are ginger (Zingiber officinale Rosc.) including elephant ginger, emprit ginger, turmeric (Curcuma domestica Val.), greater galangal (Alppinia galanga (L.) Wild.), galangal (Kaempferia galanga Linn), and finger root (Kaempferia pandurata Roxb. Schult). For analysis, DPPH (2,2-Diphenyl-1-Picrylhydrazyl), Folin–Ciocalteu reagents, 20% sodium carbonate, aquades, 10% AlCl3, 5% NaNO2, 1 mol/L NaOH, 30% ethanol, 80% ethanol, gallic acid, quercetin, methanol, spectrophotometer, moisture analyzer, water bath, chromameter, whatman filter paper and electronic scale were used.

2.2. Methods

2.2.1. Sample Screening

This sample screening process conducted to determined kind of rhizome used as samples

Then wait for 6 minutes and 1 mol/L NaOH (5 mL) was added. Then the solution is diluted until 50 mL with 30% ethanol. After waiting for 10 minutes, mixed the solution well and the absorbance of the resulting solutions was measured at 430 nm against reagent blank. Quercetin used as standard curve, the difference in concentration of quercetin prepared in 80% ethanol and its absorbance can be read at a wavelength of 430 nm using the spectrophotometer. The result is expressed in mg of quercetin/g dry weight compared to the standard curve of quercetin, which is made in the same condition of the sample (Ghasemzadeh et al. 2010).

2.2.3.7. Antioxidant Activity Analysis

From the extraction solution was taken 0.1 ml and react with 3.9 ml solution DPPH (2,2-diphenyl-1-picrylhydrazyl) 0.024 mg / mL for 30 minutes at room temperature and covered with aluminum foil. Measure sample absorbance in t = 0 and t = 30 with the spectrophotometer at wavelengths 515 nm. Control used with 0.1 ml methanol 99,98 % add with 3.9 ml DPPH 0.024 mg / mL solution after 30 minutes. This work is done 3 times. Calculated antioxidant activity as % discoloration using