To develop the Cheonggukjang with low biogenic amine content, quality characteristics of Cheonggukjang prepared with 4 strains (BaD1, BaD5, BaD16, SDA1217), which identified as Bacillus licheniformis, isolated from good quality Cheonggukjang were estimated. In addition, to develop low-fat salad-dressing made with the Cheonggukjang, biogenic amine-reduced Cheonggukjang prepared with BaD16 strain were used to prepare the salad-dressing, and quality characteristics of its was estimated. The results were as follows;

1. Moisture, crude protein, crude fat, crude ash, and carbohydrate of soybean used for preparation of Cheonggukjang were 8.44, 39.57, 22.59, 5.01, and 24.39% in average, respectively.

2. The pH and titratable acidities of Cheonggukjang showed slight different value among the strains, and colors of all Cheonggukjang showed similar value during fermentation. Major free sugars of Cheonggukjang were detected as rhamnose, xylose, glucose, sucrose, and maltose, and major organic acids were citric acid, tartaric acid, malic acid and succinic acid.

3. Twelve different types of isoflavones, including aglycones and derivatives, were detected in the Cheonggukjang prepared in this study, and genistein content was the highest. Isoflavone content in Cheonggukjang prepared with BaD1 strain was the highest 91.44±0.76 mg%.

4. Acidic protease activity of Cheonggukjang prepared with BaD5 strain was the highest 617.21±12.00 unit/g after 72 hr of fermentation. Neutral protease activity of Cheonggukjang prepared with BaD1 strain was the highest 686.00±3.64 unit/g after 72 hr of fermentation.

5. α-Amylase activities of all Cheongukjang were gradually increased during fermentation. Those of Cheonggukjang prepared with BaD5 strain were in range of 5.38±0.03~7.26±0.08 unit/g during fermentation and were higher than those of other Cheonggukjang. β-Amylase of all Cheonggukjang were decreased with fermentation time and were in range of 4.29±0.46~24.64±1.45 unit/g during fermentation.

6. Amino-type nitrogen contents of all Cheonggukjang were continually increased from 138.04±6.42~240.81±6.04 mg% after 24 hr of fermentation to 415.98±5.62~811.64±4.97 mg% after 72 hr of fermentation, and that of Cheonggukjnag prepared with BaD5 strain was the highest.

7. Total free amino acid contents of Cheonggukjang prepared with BaD5 strain were ranged from 133.57±5.25~1030.70±29.68 mg% and were higher than those of other Cheonggukjang. Glutamic acid and lysine contents were higher than other free amino acids and essential amino acids such as threonine, valine, leucine and phenylalanine were also detected.

8. Tryptamine, β-phenylethylamine, and tyramine were increased with fermentation time and putrescine, spermidine, and spermine were decreased during fermentation. Tryptamine content was the highest and dopamine, histamine, serotonin and noradrenaline were not detected. Biogenic amine contents in Cheonggukjang prepared with BaD16 strain were lower than those of the other Cheonggukjang, and BaD16 strain was evaluated as most optimal strain for preparation of biogenic amine-reduced Cheonggukjnag.

9. SDS-electrophoresis pattern in Cheonggukjang showed a molecular weight less than 25 kDa after 24 hr of fermentation, and showed a molecular weight less than 17 kDa after 72 hr of fermentation.

10. Bacillus cereus inhibition rate of Cheonggukjang prepared with BaD5 strain were more than 90% as 97.82±1.89(BaD1), 94.65±2.17(BaD5), 96.09±1.11(BaD16), 100±0.00(SDA1217), respectively.

11. The pH in salad-dressing made with the biogenic amine-reduced Cheonggukjang were in range of 3.9~4.0. Titratable acidities, colors, and soluble solid contents in salad-dressing made with the Cheonggukjang were increased with Cheonggukjang dosage, and salt content of those were not significantly differ. Major free sugars were detected as fructose, glucose, sucrose, and maltose, and major organic acids were citric acid, malic acid, succinic acid, lactic acid, and acetic acid.

12. Flow properties of salad-dressing added with the Cheonggukjang showed shear-thinning (pseudoplastic) fluid with small magnitude of flow behavior index (0.464~0.622).

13. DPPH radical scavenging activities, polyphenol contents, and ABTS radical activities in salad-dressing added with the Cheonggukjang were increased according to Cheonggukjang dosage.

14. Sensory scores on salad-dressing added with the Cheonggukjang were higher than those of salad-dressing without Cheonggukjang, and the most optimal content for low-fat salad-dressing preparation was 7% of Cheonggukjang.

In this study, Cheonggukjang were prepared with biogenic amine reducing-bacteria (BaD1, BaD5, BaD16, SDA1217), which identified as Bacillus licheniformis, and all strains were evaluated as optimal strains for Cheonggukjang preparation through the estimation of fermentation characteristics. In addition, all strains had growth inhibitory effects against B. cereus. These results proved that Cheonggukjang with hygienic safety could be prepared by biogenic amine reducing-bacteria (BaD1, BaD5, BaD16, SDA1217).
To make better convenient use of biogenic amine-reduced Cheonggukjang, salad-dressing added with the Cheonggukjang were prepared. Fibrinolytic activities and antioxidative activities of salad-dressing added with the Cheonggukjang were higher than those of salad-dressing without it. From these results, physiological activities and hygienic safety of low-fat salad-dressing could be increased by using the BA-reduced Cheonggukjang.