Abstract
Unlike the traditional preparation method for Chungkukjang, we prepared Dua-Chungkukjang with soybean fermented at $40^{\circ}C$ after the soaking, germination and steaming process, and we studied the physico-chemical characteristics of Dua-Chungkukjang. Reducing sugar content in both traditional Chungkukjang and Dua-Chungkukjang increased sharply after 10 hr of fermentation, but it decreased slightly after that. Total nitrogen content in both traditional Chungkukjang and Dua-Chungkukjang increased slowly as fermentation took place. Total nitrogen content reached 3,500 mg% and 3,700 mg%, and soluble nitrogen compound reached 750 mg% and 1,800 mg% after 40 hr of fermentation, respectively. $\beta$-Glucosidase activity increased continuously as fermentation took place, and it reached 193, 223, 235 and 248 units in Dua-Chungkukjang while it reached 125, 178, 205 and 214 units in traditional Chungkukjang after 10 hr, 20 hr, 30 hr and 40 hr of fermentation. This means that $\beta$-Glucosidase activity in Dua-Chungkukjang was $1.2{\sim}1.5$ times higher than that in the control treatment, traditional Chungkukjang. Total isoflavone content was $101.44{\mu}g$/g and $365.92{\mu}g$/g for 10 hr of fermentation, and $225.98{\mu}g$/g and $441.37{\mu}g$/g for 40 hr in traditional Chungkukjang and Dua-Chungkukjang, respectively. Isoflavone content of Dua-Chungkukjang was 2-3.5 times higher than that of traditional Chungkukjang. Anthocyanin content also increased continuously as fermentation took place, and it reached 5.0 mg/g and 6.9 mg/g in traditional Chungkukjang and Dua-Chungkukjang after 40 hr of fermentation, respectively.
종래의 전통청국장 제조방법과는 달리 원료 콩을 수침하여 균일하게 발아시켜 증자한 다음, $40^{\circ}C$에서 발효를 행한 두아청국장의 이화학적 성분 등을 검토하였다. 환원당 함량은 전통청국장 및 두아청국장 모두 발효 10 시간째까지는 급격하게 증가하였으나 그 이후부터 약간 감소하였다. 총 질소함량은 전통청국장 및 두아청국장 모두 서서히 증가하여 발효 40 시간째에 각각 약 3,500 mg%과 3,700 mg%를 나타내었으며, 수용성 질소함량은 750 mg%와 1,800 mg%를 나타내었다. 그리고 아미노태질소 함량은 발효 10시간 이후로는 아주 완만하게 증가하여 발효 40시간째에 345 mg% 및 342 mg%를 나타내었다.$\beta$-glucosidase 활성은 전통청국장에서 발효 10, 20, 30 및 40 시간째에 각각 125, 178, 205 및 214 units를 나타내었으나 두아청국장은 193, 223, 235 및 248 units를 나타내어 대조구에 비하여 $1.2{\sim}1.5$배 정도 높은 것으로 나타났다. 전통청국장 및 두아청국장의 총 isoflavone함량은 발효 10시간째에 각각 $101.44{\mu}g$/g 및 $365.92{\mu}g$/g, 40 시간째에는 $225.98{\mu}g$/g 및 $441.37{\mu}g$/g이 검출되어 두아청국장의 isoflavone함량이 전통청국장 보다 3.5배$\sim$약 2배 높은 것으로 나타났다. Anthocyanin 함량은 발효 40 시간째에 대조구인 전통청국장에서는 5.0 mg/g, 두아청국장에서는 6.9 mg/g이 검출되었다.
