Antioxidant activity and quality characteristics on the maturation period of the soy sauce with Gastrodia elata and oak mushroom (Lentinus edodes)

Abstract

This study was performed to investigate the changes in antioxidant activity and quality characteristics of soy sauce with Gastrodia elata (GK) and oak mushroom (MK) in maturation period to develop a new Kanjang product with improved functional and sensory characteristics. The pH was decreased, and the total acidity was higher in GK at 25-day maturation period. Although the total sugar content increased at 15 days with GK, it was reduced after 20 days. The reducing sugar, however, showed no notable differences after 20 days. The protease activities of GK was rapidly increased after 20 days. The total polyphenol and flavonoid contents tended to be similar and dramatically increased after 15 days. On the other hand, the DPPH radical scavenging activity of MK was higher than that of GK. These results showed that the 20-day maturation period of GK greatly enhanced its antioxidant activity and quality characteristics. It is thus expected to be used as functional materials.