• Food Science and Biotechnology
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• 제17권6호
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• pp.1279-1284
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• 2008

When cheonggukjgang was manufactured using a Bacillus subtilis CH10-1 starter culture, a short-term fermentation for 14-18 hr appeared to be the optimal for the raw cheonggukjang to avoid the formation of a bitter taste and to contain a high concentration of free sugars, whereas a long-term fermentation for more than 4 days was the optimal for the cheonggukjang for stew in order to contain a high concentration of free amino and organic acids, which are responsible for sweet, savory, and bitter tastes present in stewed cheonggukjang, During activation of murine splenic T cells with phytohemagglutinin (PHA), the presence of either poly-$\gamma$-glutamic acid ($\gamma$-PGA) or partially hydrolyzed $\gamma$-PGA resulted in reduction in the level of interferon-$\gamma$ production and enhancement in the level of interleukin-5 production, possibly due to suppression of Th1 activity and augmentation of Th2 activity. Taken together these results indicate that the raw cheonggukjang and the cheonggukjang for stew are different in their quality and taste as well as immunomodulating activity.

• Food Science and Biotechnology
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• 제16권5호
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• pp.734-739
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• 2007

This study was conducted to observe the quality characteristics of cheonggukjang fermented with new small-seed soybeans ('Agakong') according to the degree of germination of the raw soybeans. The sprouting rate was $8.6{\pm}5.6%$ after 12 hr of germination, but at 24 hr it increased rapidly to $85.4{\pm}4.7%$. We confirmed that the total isoflavone content immediately after soaking was 273.9 mg%, which was at least 3 times greater than for common soybeans; content increased at the start of germination, and increased to 338.4 mg% by 24 hr of germination, but then decreased. The quantity of viscous substance of the cheonggukjang increased in proportion to the degree of germination of the raw soybeans. The levels of amino acids in the cheonggukjang made from non-germinated soybeans, and soybeans germinated 48 hr, were 12.45 and 10.06%, respectively. The isoflavone levels in the cheonggukjang were determined by the degree of germination of the raw soybeans. There were no significant differences between the odor, sweet taste, savory taste, bitter taste, and overall acceptability of the cheonggukjang with different germination times of 0 to 36 hr.

• 한국식품과학회지
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• 제45권4호
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• pp.515-520
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• 2013

전통적인 방법으로 제조한 청국장과 볏짚시료로부터 배양방법과 비배양방법인 DGGE를 이용한 청국장의 발효미생물 군집을 분석하였다. 배양방법에서는 미륵산농원의 볏짚과 청국장 시료에서 P. agglomerans (65%)와 B. subtilis (60%)가 우점미생물로 나타내었고, 흥업토속 청국장의 볏짚과 청국장 시료에서는 B. amyloliquefaciens (57%와 52%)가 우점미생물로 확인하였다. DGGE 분석에서는 미륵산농원의 볏짚과 청국장 시료에서 P. agglomerans (Band intensity 20.6%)와 B. subtilis (Band intensity 25.7%)가 우점미생물로 나타내었고 흥업토속 청국장의 볏짚과 청국장 시료에서는 B. amyloliquefaciens (Band intensity 27.3%, 26.4%)가 우점미생물로 확인하였다. 그 외에도 볏짚에서는 Pantoea sp. Enterococcus durans, Enterobacter sp, P. ananatis, Bacillus sp., Rhodococcus sp. Pseudomonas fulva, Acinetobacter sp., B. licheniformis, B. amyloliquefaciens 등의 미생물을 확인하였고 청국장에서는 B. licheniformis, B. subtilis, Bacillus sp., B. circulans, Acinetobacter sp. 등의 미생물을 확인이 되었으며, 비배양 방법을 이용한 청국장 발효미생물 균총 조사는 배양이 불가능한 미생물을 확인할 수 있었다.

• 한국식품영양학회지
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• 제27권4호
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• pp.742-750
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• 2014

This study was done in order to investigate the changes in quality of Cheonggukjang for soybean cultivars during fermentation. Cheonggukjang of 14 cultivars that were inoculated with Bacillus subtilis 15893 was produced, and, then, it was measured for hardness, proximate composition, amino nitrogen, enzyme activity, and total aerobic bacteria counts. In a raw bean, the highest hardness value was 16,975 g from Sunyu. In a steaming bean, Jangwon had the highest hardness value and the lowest aerobic bacteria counts of forty-eight hours fermented Cheonggukjang. Saedanbaek, whose protein contents was highest in raw bean, was also highest in Cheonggukjang. The amino nitrogen content of twenty-four hours fermented Cheonggukjang was highest in Saeol and Sunyu while forty-eight hours fermented Cheonggukjang was highest in Singi, Daol, and Milyang 231. In the protease activity, Saedanbaek had the highest and total aerobic bacteria count that were either increased or held as time went on ; twenty-four hours fermented Cheonggukjang was highest in Milyang 231 and Keunol while forty-eight hours fermented Cheonggukjang was highest in Chunsang.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.282-288
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• 2023

코로나19 바이러스의 대유행으로 바이러스와 같은 외부 병원균으로부터 우리의 몸을 보호하는 면역 기능 개선 건강기능식품의 시장은 점차 증가하고 있다. 우리는 본 연구에서 높은 조단백, 조지방, 식이섬유 함량을 나타내는 고영양식품인 청국장이 면역 강화 기능을 나타냄을 밝혀내고자 하였다. 청국장 열수 추출물은 RAW 264.7 세포에서 세포독성을 나타내지 않으며, 대식세포의 nitric oxide, reactive oxygen species 및 interleukin (IL)-6, IL-1β, tumor necrosis factor-α 사이토카인의 생산량을 증가시켰다. 또한, 청국장 열수 추출물은 RAW 264.7 세포에서 inducible nitric oxide synthase 및 cyclooxygenase-2의 발현을 유의적으로 증가시켰다. 청국장 열수 추출물은 RAW 264.7 세포에서 I kappa B kinase α/β와 I kappa B (IκB)α의 인산화 및 IκBα의 degradation을 증가시켰으며, Nuclear factor-kappa B p65의 인산화를 증가시켜 p65의 세포질에서 핵으로의 이동을 촉진하였다. 이러한 연구 결과는 청국장 추출물이 선천성 면역 반응을 강화하는데 유망한 건강기능식품 소재로 활용될 수 있음을 시사한다.

• 한국식생활문화학회지
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• 제25권3호
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• pp.324-333
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• 2010

Off-flavor in foods and in raw materials is quite concerning, as it could signify deeper-rooted problems. Methods of reduction of "off-flavors" in traditional food such as Cheonggukjan and Kimchi, and in raw materials of soybean paste were studied by means of a literature review. It was found that the major components of "off-flavor" were due to butyric acid, valeric acid, alkylpyrazines, ammonia, and sulfides for Cheonggukjang, and for Kimchi were sulfur containing components such as methyl allylsulfide, dimethyl disulfide, diallyl disulfide, methyl allyl trisulfide, methyl 2-propenyldisulfide, dipropenyldisulfide. There is a demand for a scientific and systematic approach in overcoming the "off-flavor" problem. Nutritional aspects and safety should be considered. Several methods have been attempted, such as masking, binding, improving cooking process, inhibiting rancidity, and controlling the growth of micro-organism. Methods of masking were the most frequently ones used for the reduction of "off-flavor", and in some cases, othertechniques were additionally applied. The masking method would be useful in the reduction of "off-flavor" in traditional Korean foods, i.e. Cheonggukjang, Kimchi, as well as in new product development.

• 한국식품영양과학회지
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• 제46권11호
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• pp.1300-1307
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• 2017

청국장은 한국의 전통발효식품으로서 다양한 생리활성이 보고되어 있다. 본 연구에서는 B. amyloliquefaciens 균종에 속하는 신규한 균주인 B. amyloliquefaciens(SRCM 100730)에 의한 발효 청국장이 선천면역 세포인 RAW 264.7 대식세포를 활성화하는 효과를 가지는가를 검토하였다. 청국장 추출물을 RAW 264.7 세포에 처리한 결과 처리농도에 의존하여 $TNF-{\alpha}$와 NO의 생성이 증가하였으며, 이러한 면역조절 물질의 증가는 iNOS와 $TNF-{\alpha}$ mRNA 발현에서도 확인되었다. 또한, 청국장 추출물에 의한 대식세포 활성화와 관련한 세포 내 작용기전을 해석한 결과 청국장 처리에 의해 p38과 ERK와 같은 MAPK의 인산화와 $NF-{\kappa}B$ 활성화가 유도되는 것으로 밝혀졌다. 하지만 MAPK에 속하는 JNK에 대해서는 아무런 영향을 주지 않는 것으로 나타났다. 한편 청국장 추출물을 LPS와 함께 처리한 실험에 있어서 청국장 추출물은 LPS에 의한 대식세포 활성화를 촉진하여 $TNF-{\alpha}$와 NO의 생성을 증가시키는 시너지 효과를 나타내었다. 이들 결과로부터 B. amyloliquefaciens(SRCM 100730) 균주로 발효한 청국장 추출물은 대식세포를 활성화하여 선천면역을 증가시키는 효과가 있는 것으로 확인되었다.

• 한국식품과학회지
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• 제41권2호
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• pp.141-145
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• 2009

청육장은 볶은 대두를 이용하여 제조된 청국장에 해산물, 육류를 함께 가열한 반가 식품의 일종이다. 140과 220$^{\circ}C$에서 각각 21.0과 6.0분 간 볶은 대두와 이를 이용한 청국장, 청육장의 총 아이소플라본을 HPLC로 분석하였다. 총 아이소플라본 함량(${\mu}$mol/g)은 생 대두 대비 약 79-80, 56-65, 47-50%이었다. 볶음 공정으로 인해 malonyl-${\beta}$-glucosides 함량은 유의적으로 감소한 반면 acetyl-${\beta}$-glucosides와 ${\beta}$-glucosides의 함량은 유의적으로 증가하였다(p<0.05). 청국장과 청육장의 주된 아이소플라본은 ${\beta}$-glucosides 이었다. 생 대두와 볶은 대두에서는 succinyl-${\beta}$-daidzin과 succinyl-${\beta}$-genistin은 검출되지 않았고, 청국장과 청육장에서 succinyl-${\beta}$-genistin의 peak area는 succinyl-${\beta}$-daidzin 보다 더 높게 검출되었다.

• Food Science and Biotechnology
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• 제15권1호
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• pp.96-101
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• 2006

Isoflavone distribution and ${\beta}$-glucosidase activity in cheonggukjang, a traditional Korean whole soybean-fermented food prepared with or without addition of Bacillus subtilis, were analyzed every 6 hr for 36 hr. Thermal cooking of raw-soaked soybeans significantly increased ${\beta}$-glucoside isoflavone level by 57.1 % and decreased malonyl-${\beta}$-glucosides by 57.6% (p<0.05). Consistent changes of isoflavone profiles in cheonggukjang without B. subtilis addition (COB) and samples with addition of B. subtilis (CWB) were not observed during 36 hr fermentation. ${\beta}$-Glucosides of isoflavones are major forms in both COB and CWB. ${\beta}$-Glucosidase activity in cheonggukjang decreased significantly compared to that of soaked soybeans due to thermal denaturation, while recovery of enzyme activity in COB was observed. Two new unidentified peaks were detected, and their relative peak areas in CWB were significantly larger than those in COB with increasing fermentation period (p<0.05), which indicates both peaks could be associated with fermentation metabolites.

• Food Science and Biotechnology
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• 제15권4호
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• pp.643-646
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• 2006

Cheonggukjang, a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in a temperature-controlled room by traditional methods in which steamed soy was exposed to rice straw naturally rich in Bacillus species. B. subtilus and B. licheniformis were found to be the major microorganisms present in cheonggukjang made by the traditional method. We analyzed the composition of 12 kinds of isoflavones and their glycosides present in cheonggukjang collected at various fermentation times. Total isoflavone content in raw soybeans was 2,867 mg/kg and this decreased by about 50% during cooking prior to cheonggukjang preparation. However, total isoflavone content changed slightly during 45 hr of fermentation. Total content of isoflavone glycosides, consisting mainly of daidzin, glycitein, and genistin, decreased by about 40% during 45 hr of fermenting cooked soybeans. The contents of tree isoflavones including daidzein, glycitein, and genistein showed a dramatic increase during fermentation in cheonggukjang preparation, with a 2.9-, 54.0-, and 20.6-fold increase in concentration, respectively, by the end of fermentation (45 hr). In conclusion, short-term fermentation of cooked soybeans with Bacillus species caused conspicuous changes in the composition of isoflavone derivatives, and its implication in terms of health benefits deserves further study.