Antioxidant Activity of Solvent Fraction from Black Garlic

To confirm antioxidant activity of black garlic, methanol extract of black garlic was fractioned by hexane, chloroform, ethyl acetate, buthanol and water. Antioxidant activities of solvent fractions were assayed in 100, 250, 500 and 1,000 μg/mL concentrations. The contents of total phenol and flavonoids were significantly higher 5.5～11.6 times in chloroform, ethyl acetate and hexane fraction than other fractions. Antioxidant activities of solvent fractions were increased by higher sample concentrations and their activities were significantly higher in chloroform and ethyl acetate fractions than others. DPPH radical scavenging activity was over 50% in 1,000 μg/mL concentration, except butanol and water fraction. In the same concentration, reducing power was also significantly lower in butanol and water fraction. ABTS radical scavenging activity was higher in hexane, chloroform and ethyl acetate fractions and was over 70% at 1,000 μg/mL concentration. In 1,000 μg/mL concentration,
the range of hydroxy radical scavenging activity was 50.27～81.02% and SOD-like ability was 26.73～47.64%. Antioxidant activity in linoleic acid reaction system was significantly higher when storage time was longer and sample concentration was higher in non-polar solvent fractions. Nitrite scavenging activity was relatively higher than antioxidant activity and the activity in 100 μg/mL concentration was over than 50%, except butanol fraction.

Key words: black garlic, extracts, antioxidant activity