Quality characteristics of Doenjang (Soybean Paste) prepared with germinated regular soybean and black soybean

Three types of doenjang were prepared with regular soybean, germinated regular soybean, and a mixture of germinated regular and black soybean. After 90 days of fermentation, pH, moisture, and salt contents of doenjang were 6.01±0.01-6.72±0.01, 53.78±0.22-57.99±0.11, and 14.17±0.06-15.03±0.21%, respectively, showing slight differences according to soybean germination. Amylase and protease activity of doenjang changed similarly during fermentation in all samples. Amino-type nitrogen and free amino acid content of germinated black soybean doenjang after 90 days of fermentation were 1256.21±1.86 and 994.46 mg%, respectively, which were higher than those of other samples. A sensory evaluation of germinated regular soybean doenjang showed the highest scores for color, taste, and overall acceptability. These results suggest that high sensory quality doenjang can be prepared using germinated regular soybean and a mixture of germinated regular soybean and black soybean.