Methanol extracts of Cheonggukjang, fermented for various times, were evaluated for their free-radical-scavenging and tyrosinase-inhibitory activities and the underlying mechanisms were elucidated. The free-radical-scavenging activity was highest for Cheonggukjang extracts fermented for 40 h and this decreased as the fermentation time shortened. The tyrosinase-inhibition activity increased with the length of fermentation. While levels of total phenolic compounds were highest in the 40-h-fermented Cheonggukjang samples, the total flavonoid content was lower compared to samples fermented for shorter times. Therefore, the antioxidative and tyrosinase-inhibition activities exhibited by methanol-extracted Cheonggukjang samples may be attributable to the contents of total phenolic compounds.
Bibliographical noteFunding Information:
This work was supported by research grants from the Korea Science and Engineering Foundation (KOSEF) for Biofoods Research Program, the Ministry of Science and Technology, Republic of Korea.
- Free-radical-scavenging activity
- Total flavonoid content
- Total phenolic content
- Tyrosinase-inhibition activity