• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.621-629
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• 2012

This study investigated the effect of soybeans, $chungkukjang$, and $doenjang$ on blood glucose and serum lipid profile in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats weighing 205 g were divided into non-diabetic and diabetic groups. The diabetic groups were further subdivided into four experimental groups: a normal group (N), a diabetic control group (STZ-C), a diabetic group fed autoclaved soybean powder (STZ-S), a diabetic group fed $chungkukjang$ powder (STZ-CKJ) and a diabetic group fed $deonjang$ powder (STZ-DJ). Food and water intakes were higher in the diabetic groups than in the N group. The body weight gain and food efficiency ratios were higher in the STZ-S, STZ-CKJ, and STZ-DJ groups than in the STZ-C group, but created no significant changes between the diabetic groups on food intake and body weight gain. The whole blood level at 4 weeks of the STZ-CKJ group was significantly lower than the STZ-C group. Serum glucose levels of the STZ-S, STZ-CKJ, and STZ-DJ groups were significantly lower than the STZ-C group, but there was no significant change in serum insulin levels. The AST and ALP activities in serum were markedly higher in the STZ-C group, but these decreases in relation to diabetes increased in the STZ-S, STZ-CKJ, and STZ-DJ groups. The level of serum triglycerides was lower in the STZ-CKJ and STZ-DJ groups than in the STZ-C group, whereas level of serum HDL-cholesterol was higher in the STZ-CKJ and STZ-DJ groups. Levels of total serum and LDL-cholesterol were higher in the diabetic groups compared with the N group, but significantly decreased in the STZ-S, STZ-CKJ, and STZ-DJ groups compared to the STZ-C group. These results indicate that dietary supplements of soybean, $chungkukjang$ and $doenjang$ may improve blood glucose and lipid metabolism and help prevent or attenuate the progression of diabetes in STZ-induced diabetic rats.

• Research in Plant Disease
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• v.21 no.2
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• pp.58-66
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• 2015

This study was conducted to evaluate control efficacy of a fermented food 'Cheonggukjang' against cucumber powdery mildew caused by Sphaerotheca fuliginea in greenhouse. Sterilized Daepung beans were inoculated with the rice straw as natural inoculum and then incubated for 72 hrs at $42^{\circ}C$ in the household cheonggkjang maker. After 72 hrs of cheonggukjang fermentation, white zymogens were grown on the surface of a sterile Daepung beans. The pH of the 72 hrs fermented soybean was not significantly changed and electrical conductivity was found to increase by about 2 times than before fermentation. The population density of soybean zymogen showed a peak of growth at 60 hrs after fermentation and the concentration of zymogen was $8.2{\times}10^7cfu/ml$. Soybean zymogen form of the colony was divided into three kinds of bacteria and a white and a large colony (WL) was predominant bacteria among those up to 60 hrs of fermentation. To control the cucumber powdery mildew, diluted solutions of cheonggukjang was applied from 6.0% to 30.0% on cucumber leaves and they showed injury symptoms on cucumber leaves in more than 15% of them. However, more than 6.0% diluted cheonggukjang solutions showed more than 77.8% control effect of cucumber powdery mildew at 15 days after treatment. The fermented bacteria of Chenggukjang were well established in the cucumber leaf area at 15 days after treatment. The antifungal activity of 10% diluted cheonggukjang solutions was excellent for four species of plant fungal pathogens, Colletotrichum gloeosporioides, Sclerotinia cepivorum, Rhizoctonia sloani and Phytophthora capsici in the dual culture test. Results indicated that foliar application of Cheonggukjang solution could be used for the control of powdery mildews occurring on organically cultivated cucumber.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.423-428
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• 1990

Three strains among 8 isolates from the fermented chungkookjang were shown the strong phytase productivities. The phytase activities in manufacturing chungkookjang with thrse bacteria were maximized after incubating at 35-$40^{\circ}C$, pH 7.0 for 5 day. The contents of same amino acids and riboflavin were increased in chungkookjang manufactured with these phytase-producing bacteria and the rate of phytic acid degradation was much higher in chungkookjang manufactured with a single or mixed cultures of these bacteria than in traditional chungkookjang.

• Korean Journal of Microbiology
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• v.35 no.4
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• pp.296-301
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• 1999

A Bacillus strain from Korean soil was isolated and identified to be Bacillus licheniformis B1 through various biochemical tests, VITEK, and MIDI system analysis. The strain produced extracellular amylase and protease. Whether or not the strain can perform Chungkookjang fermentation with autoclaved soybean and Kanjang fermentation was determined in this study. In Chungkookjang fermentation, browining materials of strong anti-oxidant increased 8-fold, and 2-fold in Kanjang, compared with initiation material for fermentation. Maximal protease activity in Chungkookjang was observed one day after inoculation. Protease activities in Kanjang decreased to the half, and then maintained constant values during fermentation, probably due to the inhibitory effect of salt on protease activities. High molecular mass of nucleic acids was identified in Chungkookjang and Kanjang. Since the nucleic acids were not observed in autoclaved soybean, they seem to be originated from B. licheniformis B1. This study demonstrated successive fermentation of Chungkookjang and Kanjang by B. licheniformis B1 isolated from nature, and suggested possible development of food rich in browing and nucleic acids.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.288-293
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• 2007

In this study, chunggukjang was made from soybeans and Bacillus natto. This chunggukjang was meant to be consumed as a margarine and butter substitute, to help lower trans-fatty acid (TFA) intake. A freeze-dried garlic product was used during fermentation to aid in removing the smell of the chunggukjang. Chunggukjang has a very low fluidity due to its high viscosity; therefore, we added 3%(w/w) soybean oil to improve the fluidity. We found that the TFA content of the garlic chunggukiang paste was no more than 0.02${\sim}$0.05%, which was low compared to the usual contents of margarine and butter. After 4 weeks of storage the TFA content was 0.03${\sim}$0.08%, and it remained within the limits of the permissible amount. The addition of soybean oil allowed this chunggukjang to be made with greater ease, and the freeze-dried garlic eliminated the negative inherent qualities of the chunggukjang. Therefore, this garlic chunggukjang paste could be considered reasonable for commercial production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.4
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• pp.476-481
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• 2006

Effect of chitosan addition (0, 0.5 and 1% of steamed soybeans) on quality of chungkukjang fermented by Bacillus licheniformis at $40^{\circ}C$ for 48 hr was investigated. Chitosan addition did not affect the pH and slime content of chungkukjang, irrespective of chitosan concentrations. The number of total microbes was slightly lower for chungkukjang added with 1% chitosan compared with those added with 0 and 0.5% chitosan. Color L* and b* values decreased while a* value increased with increasing chitosan concentration. The contents of glucosamine, lipid, total free amino acids, and fatty acids increased with increasing chitosan concentration. Chungkukjang added with 1% chitosan showed better overall acceptability compared with those added with 0 and 0.5% chitosan.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.291-296
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• 2004

To produce functional and high nutritional chungkook-jang, an immuno-stimulating and rapid growing bacterium was isolated from one of Korean traditional food, chungkook-jang. The isolated bacterium was identified as Bacilpumilus and deposited in Korean Collection for Type Culture (KCTC 10461BP). The chungkook-jang fermented by JB-l has good taste and pleasant smell with high content of free amino acids, and the water extract of chungkook-jang showed 410% of immuno-stimulation activity at concentration of 2 mg/ml. The rapid fermentation in 16 h is achieved by inoculation of 20 ml culture broth of JB-l into 6 kg cooked soybean in commercial scale at $40^{\circ}C$.

• Journal of Life Science
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• v.23 no.1
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• pp.102-109
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• 2013

To isolate GABA-producing microorganisms, 1,500 strains were isolated from different Chungkookjang samples and screened. From these strains, 20 were selected for further analyses based on a protease and slime-producing activity test. The MC 31 strain showed the highest GABA concentration in Chungkookjang and was used in this study. MC 31 was identified as Bacillus subtilis by an API 50CHB kit and 16S rDNA sequences analysis and named as B. subtilis MC 31. B. subtilis MC 31 showed exponential growth up to 12 hours at $37^{\circ}C$ in LB broth, and it reached a stationary phase after 24 to 36 hours of incubation. B. subtilis MC 31 showed maximum GABA content at 72 hours after incubation at $40^{\circ}C$.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.176-181
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• 2004

This study was carried out to investigate the effect of yucca extract on the quality characteristics of Chungkookjang using Bacillus subtilis p01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${\alpha}-amylase$ and protease were also determined during aging of Chungkookjang. The amount of amino-type N increased gradually with time for aging. The content of amino-type N was slightly higher in Chungkookjang fermented by adding yucca extract than in the control without yucca extract. The content of ammonia-type N was slightly lower in Chungkookjang with yucca extract than in the control without yucca extract. The activities of amylase and protease were higher in Chungkookjang with yucca extract than in the control and the highest in Chungkookjang containing 0.5 mg/g of yucca extract. Organic acid contents in Chungkookjang was the highest at the initial period of fermentation. The contents of organic acids in Chungkookjang with yucca extract was higher than that in control for 48 hr of aging. The amounts of 2,5-dimethylpyrazine were increased by addition of yucca extract, while those of cis-3-hexanol were decreased.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.4
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• pp.543-550
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• 2010

This study was conducted to determine the characteristics of chungkukjang with added isoflavone extracted from arrowroot and to determine its utility as a functional food substance. Crude isoflavone was prepared from arrowroot by the ethanol extraction method and frozen dried (AI). Samples of chungkukjang each had different amounts of isoflavone extracts added to them: 0 (control), 1.76 (AC1-chungkukjang), 3.52 (AC2-chungkukjang), and 7.11 (AC3-chungkukjang) g/kg. The pH, color, slime material content, calcium, and isoflavone of each sample were measured to investigate the quality and changes in isoflavone content. As AI increased, the pH of chungkukjang decreased to 7.46~7.53 compared to the pH of control (7.63). The slime material content range increased to 4.46~6.16%. However, there was no significant difference in the general components of chungkukjang between each of the groups (Con, AC1, AC2, AC3). In colors of chungkukjang, values for $L^*$, $a^*$, and $b^*$ decreased as AI increased. Meanwhile, the calcium content of AC1, AC2 and AC3 tended to increase by 11.18~12.82% compared to the control. This may be due to the influence of Ca in the arrowroot extract powder. There was a remarkable increase in total isoflavone content, by 30.81~130.66%, with an order of AC3>AC2>AC1. In all of the groups, the content of genistein and daidzein, aglycone form, increased dramatically, by 65.00~128.34%, and 89.38~142.91%, respectively, compared to the control. In AC3, in particular the genistin and daidzin content increased by 103.47% and 188.13%. These results showed that AI can be used as a source of isoflavone supplementation in chungkukjang.