The purpose of this study was to investigate the physiochemical properties of Doenjang was fermented by added with fungi and protease. The moisture content and pH of Doenjang added with protease (WP) were lower than those of control w/o protease while the contents of titratable acidity, reducing sugar, and amino-type nitrogen in WP were higher than control. The α-amylase activities of Doenjang added with single and mixed Protease B were the highest at 4 weeks of fermentation period and protease activity of WP was about 4 times higher than that of control. The 4-9 kinds of free amino acids (proline, isoleucine, leucine, and phenylalanine etc.) in WP was increased in comparison with control. The DPPH radical scavenging activity and total polyphenol content were higher in WP than control. Total aerobic bacterial and fungal numbers were decreased depending on fermentation time regardless of addition of protease. In conclusion, the protease can be used as additives improving the quality and taste of fermented Doenjang.

• 길나영(농촌진흥청 국립농업과학원 농식품자원부 발효식품과) | Na-Young Gil (Fermented Food Science Division, Department of Agrofood Resources, National Institute of Agricultural Science, RDA, Wanju 55365, Korea)
• 최보영(농촌진흥청 국립농업과학원 농식품자원부 발효식품과) | Bo-Young Choi (Fermented Food Science Division, Department of Agrofood Resources, National Institute of Agricultural Science, RDA, Wanju 55365, Korea)
• 박신영(농촌진흥청 국립농업과학원 농식품자원부 발효식품과) | Shin-Young Park (Fermented Food Science Division, Department of Agrofood Resources, National Institute of Agricultural Science, RDA, Wanju 55365, Korea)
• 조용식(농촌진흥청 국립농업과학원 농식품자원부 발효식품과) | Yong-Sik Cho (Fermented Food Science Division, Department of Agrofood Resources, National Institute of Agricultural Science, RDA, Wanju 55365, Korea)
• 김소영(농촌진흥청 국립농업과학원 농식품자원부 발효식품과) | So-Young Kim (Fermented Food Science Division, Department of Agrofood Resources, National Institute of Agricultural Science, RDA, Wanju 55365, Korea) Corresponding author