The purpose of this study was to investigate the quality characteristics and antioxidant activity by collecting four times on six samples of Jeonbuk regional soybean pastes (Doenjang) traditionally prepared for this study. The water content of samples decreased according to progress of the aging period and the water content of the fourth sample collected was 42.40~59.64% (p<0.05). The salinity of the fourth Doenjang samples was 11.80~18.60%. The amino-type nitrogen content was 122.67~540.33 mg% immediately after the preparation of Doenjang in the Jeonbuk region and the content of the fourth collection samples increased from 251.49 to 982.36 mg% (p<0.05). The isoflavone glycosides decreased but daidzein, genistein and glycitein, which are aglycones, increased during aging periods. The total polyphenol content of the fourth collected samples was 11.99~19.27 mg GAE/g (p<0.05). The DPPH radical scavenging activity, ABTS radical scavenging activity and FARP of the fourth Doenjang samples were 51.88~81.21%, 84.14~90.32%, and 1.08~3.11 mg Trolox/g, respectively. As a result of quality analysis on Doenjang, the superiority of traditional Doenjang has been proven by the increase of amino nitrogen content and antioxidant activity according to the aging period. However, factor analysis on quality differences of regional Doenjang should be conducted to ensure standardization and quality improvement.

작두콩 된장의 품질특성을 알아보기 위해 재래식 방법으로 제조한 된장에 작두콩을 8.0% 첨가한 된장(J2)과 재래식 쌀 된장에 작두콩을 6.0% 첨가한 된장(J4)을 제조하여 시판 된장(K1-K6) 및 일반 재래 된장(J1, J3)과의 시험분석을 하였다. 수분, 회분 등 일반성분결과, 시료간 차이는 없었으나, 조단백질 함량과 protease 활성은 다른 시료에 비해 콩함량이 높은 J1과 J2가 높게 나타났으며, amylase 활성과 환원당 함량은 쌀을 첨가하여 제조한 J3과 J4가 다른 시료보다 높게 나타났다. 또한 아미노태 질소 함량은 시판된장인 K5와 K6에서 각각 668.34mg%와 642.64mg% 함량을 나타내어 다른 시료보다 높게 측정되었으며, 색도는 시료간에 유의적인 차이가 있었으며 작두콩 첨가가 색도에 큰 영향을 미치지는 않았다.

This study was carried out to analyse the biological activity in soybean pastes with the sword beans and general soybean pastes. The electron donating activity of soybean pastes with the sword beans(J2, J4) was higher than other soybean pastes with value of 81.5 ± 2.2% and 88.3 ± 0.7%, respectively. And the content of total phenol compounds was higher in J2 and J4 compared to the others with value of 1773.8 ± 2.9 mg/kg and 1785.7 ± 3.9 mg/kg respectively. ACE inhibitory effect was higher in J2 and J4 than other soybean pastes with value of 63.1 ± 1.0%, 62.1 ± 1.4%, respectively. And aglycone type(daidzein, genistein) isoflavone content was higher than glucoside type(daidzin, genistin). But tyrosinase inhibitory effect was not different among test samples. From the results, soybean pastes with the sword beans(J2, J4) have higher anti-oxidant activity and ACE inhibitory effect than other soybean pastes, therefore, it may have potential to prevent hypertension.

In this study, we tried to screen the Bacillus strain having safety probability by isolation of strains from traditional fermented food, measurement of probiotic properties, and the fermentative characteristics of Cheonggukjang. We isolated 400 Bacillus-like isolates from traditional fermented foods. Selected strains examined on the prevalent characteristic such as extracellular enzyme and antibacterial activities, and their safety probability was confirmed by biogenic amine productivity, hemolytic, and harmful substances and enzyme productivity. We selected the 5 strains by analysis of biogenic amine, antibacterial and B. cereus toxic associated gene. Five selected strains were examined on cell surface hydrophobicity, and bile and acid tolerance, and we selected the SRCM100730 as the final strain. SRCM100730 was confirmed B. amyloliquefaciens by 16S rRNA sequencing, and named the B. amyloloquefaciens SRCM100730 (KCCM11966P). Finally, we manufactured Cheonggukjang using SRCM100730 for confirmation of fermentation properties. Manufactured Cheonggukjang did not contain B. cereus, and showed that γ-PGA and extracellular enzyme activities were superior to commercial Chunggukjang. Amino nitrogen content was 544.02 mg% and 26 free amino acid were detected, and the bitterness-related amino acid content was lower than commercial Cheonggukjang. Especially, the amount of GABA was 3 fold higher than commercial Cheonggukjang. These results suggest that SRCM100730 have high availability in commercial probiotics market and fermented food industry.