• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1253-1257
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• 2017

The general characteristics, anti-mutagenicity, and in vitro anti-cancer effects of Chungkukjang, Shuidouchi, and Natto were studied. Representative brands of the three types of soybean-based short-term-fermented foods were chosen and evaluated. Chungkukjang showed the highest amino and ammonia type nitrogen contents, although Natto exhibited lower levels, and Shuidouchi showed the lowest pH and high acidity. Anti-mutagenicity was assessed by the Ames test and in vitro anti-cancer effects were assessed in HT-29 human colon cancer cells. Chungkukjang exhibited the highest anti-mutagenicity and anti-cancer effects. Based on these results, Chungkukjang showed the best functional effects, and Shuidouchi showed better functional effects than Natto. Even if such efficacies depend on raw materials and processing methods, our comparison of three types of foods from representative brands shows that Chungkukjang was the best soybean-derived product in terms of overall quality, followed by Shuidouchi and Natto. These results might be due to differences in duration of fermentation, processing method, and quality of raw materials, but further research on the basis of ethnic culture and administration method of each nation should follow.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.917-924
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• 1995

Four types of soybean paste(Doenjang), prepared with traditional Korean meju, natto meju, koji and mixture of koji and natto meju, were analyzed for compositions of free sugars and fatty acids. Crude protein content of the soybean pastes were ranged from 10.3~14.6% and in the order of traditional Korean soybena paste>natto soybena paste>koji & natto soybean paste>koji soybean paste during fermentation of Doenjang. Ethyl alcohol contnet was relatively higher in koji and natto soybean paste after fermentation for 75 days, and its content was the highest in koji soybean paste as 2.8% after fermenting for 90 days. Contents of total sugars and reducing sugars decreased during fermentation of doenjang in the order of koji soybena paste>koji and natto soybean paste>traditional soybean paste>natto soybean paste. Among the free sugars glucose, galactose, mannose and arabinose were identified in soybean paste, and glucose and galactose were more bundant. Contents of glucose and total free sugars were the highest in the traditional Korean soybean paste and galactose content was highest in koji soybean paste. In fatty acid compositions of soybean pastes, palmitic, stearic, oleic, linoleic, linolenic and arachidonic acids were analyzed, and the most abundant fatty acid was found to be oleic acid as 38.5~46.9% in all samples tested. But no significant differences in ratio of fatty acid compositions was observed from tested samples during the fermentation period.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.611-617
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• 1990

This study was conducted to breed a high vitamin $B_{12}$ producer by the fusion of protoplasts between Bacillus natto and Bacillus megaterium. Auxotrophic mutants of Bacillus natto SH-34 ($thr^-try^-rif^r$) and Bacillus megaterium BK-13 ($arg^-ade^-lys^-str^r$) which showed high protease activity and production of vitamin $B_{12}$, respectively, were isolated for the fusion experiment. Protoplasts were induced by incubating the cells with lysis solution containing $500{\mu}/ml$ lysozyme, and the ratio of protoplast and regeneration formation were ranged from 99% and 67%, respectively. Fusion frequencies of fusants between Bacillus natto SH-34 and Bacillus megaterium BK-13 were appeared in the ranges of $1.0{\times}10^{-5}$ under the treatment of 30% PEG 6000 containing 3% PVP. The fusant, MNF-72 showed the highest product yield of $7.85{\mu}g/g-cell\;vitamin\;B_{12}$ in production medium. For the improvement of productivity, the immobilization of fusants with sodium alginate was carried out. In batch and continuous fermentation systems, the productivity were determined to be $0.58{\mu}g/ml.hr\;and\;0.80{\mu}g/ml.hr\;vitamin\;B_{12}$ under optimum condition, respectivity.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.385-391
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• 1983

The change of free amino acid contents and nitrogen compounds in the course of the Chungkookjang fermentation that occurred by utilizing Bacillus natto and Bacillus subtilis are to the following effects. pH, during the growth period, that is 6.35 in pH at the first stage of fermentation, were turned into 8.2 after 72 hours. Crude protein content increased irregularly from 16.82%-18% and total sugar decreased. Increasing with the progress of fermentation time, protease activity showed the maximum value between 48-60 hours, but Bacillus natto activated a little than Bacillus subtilis. Amino nitrogen and water soluble nitrogen content increased but difference was found that is, Bacillus natto increased more than Bacillus subtilis. Glutamic acid content was the highest among the contents of free amino acid between both Bacillus sp. and the order of the next contents showed as leucine, phenylalanine, histidine alanine. arginine, but difference was found between Bacillus sp., that is, Bacillus natto was higher than Bacillus subtilis. In view of the results as above, Bacillus natto was excellent than Bacillus subtillus as Bacillus strains of Chungkookjang koji production.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.282-286
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• 1990

To extract insoluble proteins of soymilk residue by microorganism the soymilk residue was treated with crude enzyme solution from Bacillus subtilis IAM 1071 natto. Optimum conditions of pH, temperature, and digestion time were determined, and amino acid composition of the extract was obtained at $45^{\circ}C$. Under optimum conditions, the extractability with natto reached to 65% in 15hrs. The contents of essential amino acids of extract were high and specially, S-containing amino acids including methonine and cysteine and Lysine content were high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.4
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• pp.1-9
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• 1986

The mashes of soybean paste were preparea using the conventional meju fermented naturally by wild microoganisms or the new types of meju fermented by pure cultures of Aspergillus oryzae, Bacillus natto and B. subtilis to elucidate changes during the aging period. The results obtained are as follows ; The soybean paste made with conventional meiu and Asp. oryzae meju showed higher content of amino nitrogen than those of B, natto and B. subtilis meju. Soybean paste made with conventional meju contained a little more content of total and reducing sugars than other soybean pastes. ph during aging period was higher than 5.0 for the Asp. oryzae paste while less than 4.5 for B. subtilis paste. Aspartic acid. threonine, serine, glutamic acid, glycine, alanine, cystine, valine, methionne, leucine and histidine for Asp. oryzae paste ; tyrosine, arginine and proline for conventional meju paste; and isoleucine and phenylalanine for B. subtilis paste were found to be peak amount 90 days after the preparation. The content of total free amino acid was high in the order of Asp. oryzae paste, conventional paste, B. natto paste and B. subtilis paste.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.599-604
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• 1991

The physico-chemical properties of viscous substances extracted from chungkook-jang were investigated. The crude protein content of the viscous substance was approximately 61% and 32% of the crude protein content was amino type nitrogen. The contents of glutamic acid in amino acids and potassium in minerals of viscous substances were more higher than those of raw soybean and chungkook-jang. The viscosity of 5% viscous substance solution was higher than that of 15% sucrose solution. The transmittance of viscous substance solutions from Bacillus natto and Bacillus subtilis was lowest at pH 5.0, the absorbances were lowest at pH 5.5 and pH 4.0, respectively. The fibrinolytic activity of viscous substances by B. natto and B. subtilis was 0.438 and 0.163 unit/mg protein, respectively. Though viscous substances were heated for 5 min and 30 min at $100^{\circ}C$, 90% of and 45% the fibrinolytic activity was remained, respectively.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.405-410
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• 2004

This study was performed to investigate the antioxidative activity of soybean products extracts using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and thiobarbituric acid (TBA) method for application of animal products. All three extracts (natto, soybean paste, soybean milk extract) were found to have an ability to donate hydrogen to DPPH. Especially, natto and soybean paste extract were more effective than that of soybean milk on the antioxidative activities. Natto and soybean paste extract were stronger than butylhydroxy toluene (BHT), butyl hydroxyl anisole (BHA) (5${\times}$10$^{-4}$ M) and ascorbic acid (5.7${\times}$10$^{-3}$ M) previously well known as antioxidants. These extracts also showed a synergistic effect. TBA values of natto (45.8％) and soybean paste extract (45.2％) were stronger than that of soybean milk extract (33.6％). These results suggest that soybean product extracts have antioxidative activities and synergistic effects.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.229-234
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• 1989

Cooked soybeans were fermented with B. subtilis and B. natto for 48 hrs and 74 hrs. The odor concentrates of during these Chungkookjang fermentation were obtained with a simultaneous distillation and extraction system. The seperation and identification were carried out by GC and GC-MS. The main components of the cooked odor concentrate of soybeans were 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol etc.. In Chungkookjang (B. subtilis inoculation), 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol remained but alkyl pyrazines such as 2,5-dimethyl pyrazine, trimethyl pyrazine and tetramethyl pyrazine increased and those increased during the fermentation. In Chungkookjang(B. natto inoculation), 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol, main components of cooked soybeans decreased and alkyl pyrazines increased, especially, tetramethyl pyrazine remarkably increased during fermentation. From the result, it seems that alkyl pyrazines caused the characteristic odor of Chungkookjang and mask the beany odor.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2005.10a
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• pp.46-54
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• 2005

대두에는 이소플라본(isoflavone), 콩단백질, 올리고당(oligosaccharides), 식이섬유(dietary fiber), pretense inhibitor, 사포닌(saponin), 피틴산(phytic acid), 피니톨(pinitol) 등과 같은 다양한 기능성 성분이 함유되어있다. 대두 이소플라본의 경우, boiling, steaming, roasting의 가열 방법 중 roasting이 손실을 최소화하는 가열방법이며, 대두제품 중에는 대두, natto, 두부, 두유, 된장, 고추장 순으로 함량이 감소한다. 대두나 단순대두 가공품의 경우는 glucoside의 비율이 높은 것에 비하여, natto를 제외한 발효 대두에 있어서 aglycone의 함량이 상대적으로 더 높게 나타난다. 대두 올리고당 함량(%)은 생대두분말(2.87)>대두(2.75)>두유(2.59)>두부(0.56)>natto(0.34) 순으로 높다. 생대두의 경우 상당량의 BBPI(Bowman-Birk pretense inhibitor)가 함유되어 있으나 다양한 가공, 조리 공정을 거친 대두 가공제품의 경우 대부분의 BBPI가 소실 또는 불활성화 되는 것으로 나타난다. 대두 phytate는 열과 수침에 비교적 안정하나, 발표기간이 길어지면 함량이 감소한다. 대두 피니톨은 수용성이며 열 및 산, 알칼리 조건에서 매우 안정하다. 대두는 생으로 섭취하지 않고 익혀서 먹거나, 다양한 대두제품의 형태로 섭취하므로, 생리활성을 기대하며 대두제품을 섭취할 때, 대두의 조리 및 가공 과정이 기능성 성분에 미치는 영향을 고려하는 것이 필요하다고 사료된다.