• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1271-1276
• /
• 2009

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.

• Food Science and Preservation
• /
• v.14 no.4
• /
• pp.356-363
• /
• 2007

This study investigated the effects of a Hwangki (Astragalus membranaceus) extract on the quality of Chungkukjang fermented by Bacillus subtilis KCCM 12148, at 30, 40, and $50^{\circ}C$, for 4 days. Changes in moisture contents, protein levels, pH values, ammonia-type nitrogen levels, color, angiotensin-converting-enzyme (ACE) inhibition rates, and fibrinolytic activities, were all determined. For both control and test, the moisture contents decreased gradually with time and the protein levels increased slightly. The pH values fell at the beginning of fermentation and then rose. The content of ammonia-type nitrogen was higher in Hwangki with Chungkukjang than in control, until 24 hr after fermentation commenced. After that time, the content of ammonia-type nitrogen control was higher in the control than in the Hwangki with Chungkukjang sample. Color features, such as lightness, redness, and yellowness, all decreased during fermentation, in both control and test. The highest ACE inhibition rates during fermentation at $40^{\circ}C$ were 90.9% in the control (48 hr after fermentation commenced) and 95.3% in Hwangki with Chungkukjang(24 hr). Fibrinolytic activities of Chungkukjang and Hwangki Chungkukjang were 100.7 and 74.4% respectively. The content of 2,6-dimethyl pyrazine in the control was higher than that in Hwangki with Chungkukjang. Sensory evaluationtests showed that the addition of Hwangki significantly improved the overall palatability of Chungkukjang.

• Food Engineering Progress
• /
• v.15 no.4
• /
• pp.355-361
• /
• 2011

The separation conditions for the enhancement of isoflavone contents in soybean by soaking and germination were developed, and the fermentation conditions of Chungkukjang were optimized by using response surface methodology analysis. The high-yield of isoflavone production was obtained when the conditions of soaking and gemination were at 25.6$^{\circ}C$, 7 hr and 29.1$^{\circ}C$, 42.4 hr, respectively. Total isoflavone contents in soybean (Daepung) by treatment were increased from 1,012 ppm to 1,912 ppm. Also, the optimum fermentation conditions of Chungkukjang were determined 39.96$^{\circ}C$, 1.32% (inoulum size) and 42.4 hr, respectively. Isoflavone contents in Chungkugjang under the optimum fermentation conditions were 1.3 times higher than the control (1,960 ppm).

• Journal of Sensor Science and Technology
• /
• v.18 no.1
• /
• pp.72-76
• /
• 2009

The sensing system was designed and fabricated to investigate the ferment environment of soybeans. $NH_3$ gas was saturated after about 7 h and $CO_2$ gas was reached the peak after about 8 h in the inoculation of Bacillus subtilis. However, times that $CO_2$ gas and $NH_3$ gas were reached maximum value without Bacillus subtilis were about 15 h and 18 h, respectively. The sample that inoculated Bacillus subtils had deeper taste than one without it. We found that the peak time of $CO_2$ gas means the starting time of fermentation. If we control the operating time after the start of fermentation, it is expected to make a suitable Chungkukjang to individual preference.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.4
• /
• pp.507-515
• /
• 2008

This study investigated the standard recipe and changes in the quality characteristics of Chungkukjang-Kimchi (CKK) and evaluated its acceptance by elementary school students. The acceptability of Kimchi among elementary school students was evaluated by monitoring the plate waste rate. Chungkukjang powder was added to the Kimchi recipe at 0, 20, 40, 60% of the total weight of red pepper powder. The pH of the CKK decreased as fermentation proceeded, and the total acidity was $0.24{\sim}0.25%$ in all samples. The salinity of the CKK was 2.32%. The L color value was significantly lower in the treatment groups than in the control group. The b and a color values increased in the beginning, but tended to decrease during fermentation. In the sensory evaluation, there was no significant difference in appearance on preparation day, but there were significant differences on the 6th (p<0.05) and 20th days (p<0.01), with the highest scores observed in the 40% added group. Sourness increased significantly (p<0.001) during fermentation in all samples. There were significant differences (p<0.001) in crispness on the 3rd day among the treatment groups, and it tended to decrease as fermentation progressed. There were significant differences in flavor during the early stage (p<0.001), but there were no differences as fermentation proceeded. Overall acceptability was high in the 40% added group. Evaluation of acceptability by monitoring the plate waste rate in the school dining room showed that acceptability was highest in the 20% added group. Thus, it was concluded that acceptability among elementary school students was highest for CKK from the 20% Chungkukjang group.

• Korean Journal of Food Science and Technology
• /
• v.3 no.1
• /
• pp.64-67
• /
• 1971

The Manufacturing conditions of Chungkukjang were investigated by the use of the soy beans, salt (NaCl) and Bacillus subtilis S.P. In the studies of Chungkukjang Meju protease activity, total acid, free amino nitrogen, optimum times of fermentation and the maturity of Meju were shown the reasonable conditions each at 54 hrs, 24 hrs, between 36 to 42 hrs, between 36 to 42 hrs and at 5 days from the beginning of fermentation. In the studies on the Chungkukjang (Sauce made by meju) the increased amount of free amino nitrogen and total acid were proportional to the increased contents of moisture. The amount of the acid was increased rapidly for 20 day from the beginning and after it slowly. The appropriate content of moisture was 55% in the manufacturing of Chungkukjang.

• Journal of Life Science
• /
• v.12 no.3
• /
• pp.357-362
• /
• 2002

A bacterial strain showing the fibrinolytic activity was screened from korean traditional soybean products. For the identification, the strain was investigated morphology and biochemical characteristics and it was classified to Bacillus subtilis. The strain had high fibrinolytic activity in Chungkukjang. The optimum fermentation condition of temperature and time were 37$^{\circ}C$ and 24hour. The pH in Chungkukjang was gradually alkalized during fermentation. The fibrinolytic enzyme in Chungkukjang stable at heft treatment; After heating at 6$0^{\circ}C$ and 8$0^{\circ}C$ for 30 min, the fibrinolytic activity remained 75% and 40%, respectively.

• Culinary science and hospitality research
• /
• v.12 no.4 s.31
• /
• pp.225-235
• /
• 2006

This study was carried out to investigate the optimum conditions for the preparation of natto(unripe Chungkukjang) using Sowonkong(small soybeans) and Bacillus subtilis KCCM 11315. The changes in the contents of amino-type nitrogen, ammonia-type nitrogen, total acidity and total sugar, and those in the pH, browning materials and microbial growth were determined during fermentation and aging of natto(unripe Chungkukjang). The amounts of amino-type nitrogen and ammonia-type nitrogen were increased gradually during the fermentation at $40^{\circ}C$ for 72 hours, but those of total acidity and total sugar were decreased. The pH was gradually alkalized, and more water soluble browning materials were produced during fermentation. The number of viable cells was the highest at the 36 hours of fermentation. The content of ammonia-type nitrogen was significantly decreased during aging at $4^{\circ}C$ for 48 hours. In view of the results as above, it seems possible to conclude that the natto(unripe Chungkukjang) fermented by Bacillus subtilis KCCM 11315 at $40^{\circ}C$ for 36 hours and then aged at $4^{\circ}C$ for 48 hours was suitable for manufacturing natto(unripe Chungkukjang).

• Korean journal of food and cookery science
• /
• v.23 no.4 s.100
• /
• pp.481-491
• /
• 2007

This study was conducted to develop pizza crust with additions of Chungkukjang and onion. The stickiness of the pizza dough containing fresh Chungkukjang (C), heated Chungkukjang (HC), and fresh Chungkukjang with added dough-improver (CI), was measured to evaluate the dough properties. The optimum conditions for pizza crust preparation relating to the processing suitability and sensory quality were established using response surface methodology (RSM). When HC and CI were used in dough making, dough stickiness was reduced to 37% and 51%, respectively. Therefore, the dough-improver(2%) offered the pizza dough better rheological properties when C was used without heat treatment. On the other hand, processing suitability such as the spreadability and overall acceptability, which included the smell and taste of the pizza, were impaired as the amount of CI increased. However, the use of fresh ground onion in the pizza dough compensated for these impairments. The optimum conditions for pizza crust making as determined by RSM were 25.1% onion, 7.1% Chungkukjang, and 52.3 min of fermentation time.

• Korean journal of food and cookery science
• /
• v.21 no.2 s.86
• /
• pp.163-170
• /
• 2005

Soybean is an important plant as the source of protein and oil, as well as phytochemicals such as genistien, daidzein, phenolic acids, phytic acid, tocopherol, and saponin. Chungkukjang, a fermented soybean paste, is common in Korean meals and bacillus is usually used in the fermentation of steamed soybean. For its processing, whole soybeans are boiled in water until the beans are soft, and then the drained beans are wrapped with rice straw or starter and set in a warm place at $65^{\circ}C\;for\;3\;\~\;4\;days$. Normally, the remaining cooked water which was drained from the steamed beans is discarded. We supposed that this water possesses hish amounts of useful components, and we therefore developed a modified method using the cooked water. After fermentation, we added the remaining cooked water which had been drained from the beans to the fermented soy beans and boiled them together. To investigate the bio-functionality of the modified Chungkukjang, the total antioxidative activity, isoflavones contents, phenolic acids, and 3-deoxyglucosone (3-DG) were measured at each stage of the preparation of chungkukjang. The original and modified chungkukjang possessed a high antioxidative activity compared with the other samples, as did the drained water after steaming of the soybean. The contents of genistein, daidzein, and phenolic acids, which contained antioxidative activity, were also increased in the original chungkukjang and their contents were similar in the modified chungkukjang. The content of 3-DG was increased in the modified chungkukjang compare with the original. It is suggested that the active soybean components delivered to the drained water during the steaming process were useful for increasing the bio-functionality of the modified chungkukjang.