• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.274-279
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• 2014

The objective of this study was to investigate the fermentation characteristics of cheonggukjang made with smoked soybeans. The study found that the amino nitrogen content and pH of cheonggukjang made with smoked soybean (CSS) were significantly elevated compared to that of cheonggukjang made with non-smoked soybeans (CNS). On the other hand, the moisture content of CSS was significantly lower when compared to that of CNS. Moreover, there were no significant differences in the viscous substance content between CNS ($5.8{\pm}0.2%$) and CSS ($5.6{\pm}0.3%$). In terms of colour, the L and b values of CSS were higher than that of CNS, whereas the a value of CNS was higher than that of CSS. Hence, it was confirmed that the total isoflavone contents in CSS ($1,624.6{\pm}53.2{\mu}g/g$) were higher than that in CNS ($1,590.6{\pm}59.3{\mu}g/g$). In both CSS and CNS, the content of genistin was highest followed by glacitin and daidzein. Also, the number of aerobic bacteria in CNS ($8.1{\pm}0.4\;log\;cfu/g$) was higher than that in CSS ($7.3{\pm}0.3\;log\;cfu/g$). Taken together, a smoking process can useful for the development of new cheonggukjang products.

• Food Science and Preservation
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• v.15 no.6
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• pp.872-877
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• 2008

This study was carried out to provide basic information related to improvement of flavor and consumption of cheonggukjang. Red ginseng cheonggukjang (RGC) and Rubus coreanum cheonggukjang (RCC) extracts were prepared, and their physicochemical characteristics were compared with either general cheonggukjang (GC) or non-fermented boiled soybean (BS). The moisture and crude fat contents were not significantly different among samples. RGC had the highest reducing sugar content and BS had the lowest. The free sugar content of RGC was higher than that of either GC or RCC, and the major free sugars present were glucose, fructose and sucrose. Seventeen free amino acids were detected in BS and cheonggukjang, and the content of free amino acids ranged from 1,233.8 to 2,599.6 mg/100 g. The greatest content of free amino acids was found in RGC. Color L, a and b values were highest in BS and lowest in RCC. The hardness and strength of RGC and RCC were lower than for GC.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.699-707
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• 2013

This study was conducted to examine the effects of Cheonggukjang powder made using black foods on liver function and lipid composition in streptozotocin(STZ)-induced diabetic rats. The experimental animals were divided into 5 groups and fed the following for 7 weeks; normal diet(control), STZ+normal diet(Diabetic), STZ+50% soybean Cheonggukjang supplementation(DSC), STZ+44.5% yakkong Cheonggukjang supplementation(DYC), and STZ+supplementation with 50% yakkong black food(black rice, black sesame seeds, and sea tangle) Cheonggukjang(DYCB). The results showed that the body weight gain and food efficiency ratio of the STZ-induced diabetic groups were significantly lower than those of the control group. In the Diabetic group, glutamic oxaloacetic transaminase(GOT) and glutamic pyruvic transaminase(GPT) activities and total bilirubin content in serum were significantly greater than those in the control group. However, supplementation with Cheonggukjang reduced these values. In the Diabetic group, the triglyceride, total cholesterol, and low-density lipoprotein(LDL)-cholesterol contents in the serum and liver tissue, as well as the atherogenic index(AI) and cardiac risk factors(CRF) were significantly higher than the corresponding values in the control group, although the high-density lipoprotein(HDL)-cholesterol and phospholipid contents were significantly lower than those in the control group. However, supplementation with Cheonggukjang normalized the changed lipid composition in the STZ-induced diabetic rats. Further, yakkong Cheonggukjang and black food contaning yakkong Cheonggukjang normalized AI and CRF.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.475-478
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• 2003

Bacillus subtilis K-20 chunggukjang is widely used in making soy sauces and bean pastes which are Korean traditional fermented foods. Bacillus subtilis K-20 chunggukjang was cultured, and fermented at $40^{\circ}C$ and 90% humidity for 96 hr after homogenizing with garlic, garlic and onion, and garlic, onion, and ginger. As a result, a product with pizza flavor and taste was obtained from Bacillus subtilis K-20. This product could be used as a functional food to promote immunity.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2003.11a
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• pp.139.1-139
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• 2003

청국장은 삶은 콩을 고초균으로 불리는 Bacillus subtilis를 이용하여 발효시킨 전통조미식품으로, 최근 혈전용해효소의 함유뿐만 아니라 항돌연변이, 항고혈압, 항암효과 등이 검증되어 기능성 식품으로서 새로운 관심의 대상이 되고 있다. 그러나, 청국장의 독특한 불쾌취는 특히 젊은 세대의 섭취 기피 원인이 되고 있고, 찌개 형태의 단순한 조리법은 이용 방법면에서 한계를 가지고 있다. 따라서 영양이 풍부하고 우수한 생리활성효과를 가진 청국장의 계승 발전과 소비 진작을 위하여 청국장의 기호성, 편의성 등을 강화하고 청국장의 제조법을 간편화하는 연구가 필요한 실정이다.

• Journal of Life Science
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• v.18 no.10
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• pp.1420-1425
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• 2008

This study was conducted to investigate the fermentation characteristics of cheonggukjang prepared with soybean germinated under light condition. The moisture content and pH of cheonggukjang made with soybean germinated under light condition (CGL) were higher than that of cheonggukjang made with non-germinated soybean (CNG). The color of CGL was darker than that of CNG and cheonggukjang made with soybean germinated under dark condition (CGD). The number of live bacteria in the CGL ($10.7{\pm}0.3\;\log\;CFU/g$) and CGD ($10.7{\pm}0.4\;\log\;CFU/g$) was higher than that of CNG ($9.7{\pm}0.4\;\log\;CFU/g$). The levels of isoflavone in CGL, CGD and CNG were 2,038.0, 1,993.6 and 1,747.0 ug/g, respectively. There were no significant differences in the appearance, aroma, taste and overall acceptability of the cheonggukjang made with different germination conditions. Therefore, it was expected that the cheonggukjang prepared with soybean germinated under light condition could be practically used as a new fermented food.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.133-141
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• 2009

This study was carried out in order to investigate the changes in chemical components of four kinds of Cheonggukjang during fermentation. Three different kinds of Cheonggukjang were prepared with germinated soybeans using rice straw, Bacillus natto, Bacillus natto plus Aspergillus oryzae, and non-germinated soybeans using rice straw. The nitrogen contents increased significantly during fermentation in all kinds of Cheonggukjang. Especially germinated soybean Cheonggukjang prepared with A. oryzae plus B. natto showed approximately 1.3 to 3.0 fold higher values than the other Cheonggukjangs. Total free amino acid contents of all Cheonggukjangs increased with an increase in fermentation time until 60 h. Lysine content was highest in Cheonggukjang prepared with ungerminated soybean at 72 h of fermentation. Among free amino acids of germinated soybean Cheonggukjang prepared with rice straw, glutamic acid was highest (3.64 mg/g) after 72 h of fermentation. In Cheonggukjang prepared with mixed culture, glutamic acid content was 4.37 mg/g. Total carbohydrate contents of Cheonggukjang decreased rapidly with an increase in fermentation time except the ungerminated soybean Cheonggukjang, and the total carbohydrate contents varied from 9.81 to 14.04% after 72 h of fermentation. On the other hand, total carbohydrate contents of ungerminated soybean Cheonggukjang prepared with rice straw gradually decreased during fermentation. In conclusion, it is expected to increase the contents of functional constituents and to improve quality characteristics of Cheonggukjang when it is prepared with germinated soybeans using B. natto plus A. oryaze.

• Food Engineering Progress
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• v.21 no.2
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• pp.126-131
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• 2017

Millimeter waves are electromagnetic waves with frequencies of 30-300 GHz (wavelength 1-10 mm), and millimeter wave stimulation affects microorganism growth. The present study stimulated Bacillus subtilis with 60 and 70 GHz millimeter waves during cheonggukjang fermentation and characterized the effects on cheonggukjang quality. Cheonggukjang treated with millimeter wave irradiation showed no significant difference in total bacterial count but generated only 5.52-5.92% viscous substance. Irradiation with 60 GHz millimeter waves yielded bright and intense color values relative to 70 GHz millimeter waves. Examination of the amylase activity and reducing sugar content of finished cheonggukjang revealed that irradiation at 70 GHz inhibited amylase activity in cheonggukjang. Furthermore, irradiation at 70 GHz increased protease activity, whereas irradiation at 60 GHz inhibited the activity. Moreover, the amino acid content changed with millimeter wave irradiation.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.936-941
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• 2000

To assess functional properties of chungkugjang (CK), a traditional Korean soyfood, fermented with black beans at $42^{\circ}C$ for 72 hrs, some biological activities of methanol extract of CK and the changes in phytoesterogen (daidzein, genistein) contents during fermentation were investigated. The methanol extract of CK (MEC) prepared with soybean had no or a little antibacterial activity. MEC prepared with black bean inhibited the growth of all bacteria tested, and MEC of small black bean was higher in antibacterial activity than that of large black bean. Hydrogen-donating activities of MEC of large and small black bean were 76.4 and 75.5%, respectively, which were higher than that of soybean being 67.3%. Nitrite-scavenging activity was found to be above 90% in all MECs tested as compared with control group. MEC showed strong antioxidant activities against both peroxidation of linoleic acid and $H_{2}O_{2}-FeSO_{4}-induced$ peroxidation of rat liver homogenate. The antioxidant activities were high in the order of small black bean, large black bean and soybean. Contents of genistein and daidzein were gradually increased during fermentation of CK. The isoflavones were higher in black bean CK than in soybean CK and higher in large black bean CK than in small black bean CK. In black beans genistein content was about twice as much of daidzein.

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