Multiple starters consisting of two Bacillus amyloliquefaciens strains (MJ1-4 and EMD17), Pichiafarinosa SY80, and Rhizopus oryzae were used for Doenjang making. Bacillus strains were selected based on their abilities to inhibit toxinogenic fungi and Bacillus cereus, fibrinolytic activity, and their ability to confer good flavor to Cheonggukjang. P. farinosa SY80 and R. oryzae, previously isolated from soy sauce, were selected because they were not inhibited by two bacilli. Doenjang was prepared by inoculation of multiple starters (A1 Doenjang). Control Doenjang was prepared by inoculation of B. subtilis KACC 16750 (Natto strain) and Aspergillus oryzae KCCM 60166 (A2 Doenjang). Another control (A3 Doenjang) was prepared by inoculation of microorganisms present in rice straw. Doenjang samples were fermented for 70 days at 20℃. pH of 3 samples decreased from the initial value of 6.4 to 5.8~6.0 and titratable acidity (TA) increased from 0.6 to 1.1~1.3. The amount of amino-type nitrogen increased during fermentation. There were slight differences in moisture, crude-protein, and crude-fat contents after 70 days. Contamination of fungi was observed only in A3 Doenjang and B. cereus was not detected from all 3 samples. A1 Doenjang showed the highest fibrinolytic activity and A2 Doenjang the second. These results indicate that Doenjang made with carefully selected starters was functionally improved and microbially more safe.

I. Introduction
 II. Materials and Methods
  2.1 Preparation of Doenjang
  2.2 Analyses of Doenjang during fermentation
  2.3 Amino-type nitrogen contents of Doenjang samples
  2.4 Reducing sugar contents of Doenjang samples
  2.5 Fibrinolytic activities of Doenjang samples
  2.6 Sensory evaluation
  2.7 Statistical analyses
 III. Results and Discussion
  3.1 Changes in pH and TA of Doenjang duringfermentation
  3.2 Changes in chemical components of Doenjangduring fermentation
  3.3 Fibrinolytic activity and antimicrobial activity ofDoenjang
  3.4 Sensory evaluation of Doenjang
 IV. Acknowledgments
 » Literature cited

• Min Jeong Cho(Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Korea)
• Jae Yong Lee(Division of Applied Life Science (BK21 Plus), Graduate School, Gyeongsang National University, Jinju 660-701, Korea)
• Kang Wook Lee(Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Korea)
• Kye Man Cho(Department of Food Science, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea)
• Chang Kwon Lee(Mong-Go Foods Co., Ltd., Changwon 641-465, Korea)
• Gyeong Min Kim(Garlic Research Institute, Namhae 668-812, Korea)
• Jeong Hee Shin(Garlic Research Institute, Namhae 668-812, Korea)
• Jong Sang Kim(School of Applied Biosciences and Food Science and Biotechnology, Kyungpook National University, Daegu 702-701, Korea)
• Hyun-Jin Kim(Division of Applied Life Science (BK21 Plus), Graduate School, Gyeongsang National University, Jinju 660-701, Korea)
• Jeong Hwan Kim(Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Korea, Division of Applied Life Science (BK21 Plus), Graduate School, Gyeongsang National University, Jinju 660-701, Korea) Corresponding author