ESTIMATION OF THE DPPH ANTIOXIDANT AND POLYPHENOL CONTENTS FROM CHEONGGUKJANG

Ryang Jeong Ju, Ju Yeon Lee, Tae Gyeong Moon, Kyung Jin Kang, Min Woo Lee and Man Kyu Huh*

ABSTRACT

Cheonggukjang is a traditional fermented soybean food product manufactured using steamed soybeans. This study is planned to determine the antioxidant activity of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and total phenol content of Cheonggukjang. The inhibition percentage values of aqueous, ethanol, and methanol extracts at 1.0 mg/ml were 31.17%, 29.2%, and 27.4%, respectively. However, the all groups did not show a statistically significant difference (t = 0.108, df=2, p > 0.05. The values of IC50 were following: methanol extract (102.96 mg/mL) > ethanol extract (98.02 mg/mL) > aqueous extract (97.01 mg/mL). Total phenols as determined by the Folin-Ciocalteu method varied from 1.6 mg/L to 3.57 mg/L. There was no significant difference in total phenol content among extract solvents (p > 0.05). It is obvious that the fermentation of soybean broth could result in better antioxidant properties.

Keywords: Antioxidant, Cheonggukjang, DPPH, total phenol content.