• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.991-995
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• 2013

This study was conducted to develop an edible culture media with various types of cereals and soybeans for the pre-cultivation of lactic acid bacteria (LAB). To manufacture the edible culture media, LAB enrichment media were prepared using cereals such as brown rice (including germinated brown rice, glutinous brown rice, and germinated glutinous brown rice), yellow soybeans (including yellow soybeans, hulled yellow soybeans, germinated yellow soybeans, hulled and germinated yellow soybeans), and black soybeans (black soybeans, hulled black soybeans, germinated black soybeans, hulled and germinated black soybeans). Seven species of LAB were used in the experiment: Lactobacillus (Lb.) farciminis, Lb. homohiochii, Lb. pentosus, Lb. plantarum, Leuconostoc (Leu.) paramesenteroides, Leu. citreum, and Leu. lactis. For edible culture media from cereals, the average viable cell count of the seven starter cultures was 7.6~8.0 log CFU/mL, while that of the MRS culture medium, a synthetic medium, was 9.2 log CFU/mL; thus proliferation was lower by about 1~2 log CFU/mL in starter cultures from cereals compared to the synthetic medium. In the case of the edible culture media from soybeans, most bacteria showed higher proliferation in the hulled and germinated soybean media. In particular, Lb. plantarum showed the highest cell count at 10.08 log CFU/mL. In the case of edible culture media from black soybeans, the proliferation rate was higher in the hulled and germinated black soybean medium. Lb. homohiochii showed the highest proliferation in the hulled and germinated black soybean medium at 9.90 log CFU/mL. All results show that edible culture media using cereals and soybeans are generally good for LAB. Especially, hulled and germinated black soybeans are optimal for the pre-cultivation of LAB medium.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.57-63
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• 1971

1) Among five lactic acid bacteria examined, Str. thermophilus and Str. diacetilactis produced remarkably greater amount of acids in soybean milk than Str. lactis, Str. cremoris and L. bulgaricus. 2) Soybean milk and skimmed dry milk were combined in the ratio of 7 : 3 and were carried out in lactic acid fermentation for 24 hours at optimum temperature. The result indicated that the yield of precipitation and protein content of it were the most, the moisture content was the least and curd structure formed was considered too hard. 3) Based on these and other results, following procedure was used for manufacturing: soybean milk and skimmed dry milk were combined in the ratio of 7 : 3, heated at $121^{\circ}C$ for 20 min., cooled, added Str. thermophilus as lactic acid starter and incubated for 24 hours and $37{\pm}1^{\circ}C$. The curd was cooked, hooped, and pressed for 24 hours, to the surface of which, Penicillium caseicolum and sodium chloride were spread. During ripening of the curd at $15^{\circ}C$ and $85{\sim}90%$ RH for 21 days, Pen. caseicolum was highly developed after 7 days, pH was increased and proteolytie activity has reached to the peak point after 14 days. After 7 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino acids nitrogen were begun to increase. After 21 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino-N reached to 52%, 32% and 14% of total nitogen. In the soybean cheese, after 21 days of ripening, 17 or more kinds of amino acids were detected by two-dimentional paper chromatography. The product contained 63.2% of moisture, 17.5% of crude protein, 13.2% of crude fat, 2.8% of crude ash and 2.5% of sodium chloride.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.172-176
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• 2012

Doenjang is a traditional Korean fermented soybean product that provides a major source of protein. In this study, a total of 18 different home-made doenjang samples were examined for the presence of foodborne pathogens and the total aflatoxin levels. Using an enzyme-linked immunosorbent assay to assess microbial quality and potential public health risk, we showed that total coliform levels in the doenjang samples ranged from 0 to $4.43{\pm}2.32{\times}10^6\;CFU/g$, and the maximum limit of Bacillus cereus was $4.67{\pm}2.0{\times}10^5\;CFU/g$. However, other foodborne pathogens, such as Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella spp., were not detected among the tested samples. One of the samples (S3) showed a maximum limit of $42.2{\pm}9.1\;{\mu}g/kg$ for aflatoxin levels, which was above the safety limit allowed by the Codex Alimentarius Commission (CAC) regulatory agency. Further research is necessary to determine whether and how doenjang safety can be improved via elimination/reduction of microbial contamination during fermentation and storage or using microbial starter cultures for its fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1010-1016
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• 1999

Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.

• Food Science and Preservation
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• v.19 no.4
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• pp.547-553
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• 2012

Cheongkookjang that was prepared with three kinds of soybeans [non-germinated soybean (NG), soybeans germinated for 12 hr (GS12), and soybeans germinated for 24 hr (GS24)] were investigated. The changes in the pH, total aerobes, and slime content of Cheongkookjangs that were prepared with NG, GS12 and GS24 did not significantly differ during their fermentation for 48 hr at $40^{\circ}C$. The total aerobes of the Cheongkookjang variants reached $10^8{\sim}10^9$ CFU/mL after theirfermentation for 48 hr. The total polyphenol content and DPPH-radical-scavenging activities the germionated and non-germinated soybeans did not significantly differ, but increased significantly according to the germination degree during the fermentation. The isoflavone content of the Cheongkookjang with the germinated soybean increased. The isoflavone content of Cheongkookjang variant were 0.141 mg/g (NG), 0.369 mg/g (GS12) and 0.569 mg/g (GS24); their free amino acid contents were 254.26 mg% (NG), 337.49 mg% (GS12) and 528.78 mg% (GS24); and their sensory characteristics such as their taste, color, flavor, bitter taste, texture, and overall acceptability did not significantly differ.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.34-44
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• 1984

This experiment was carried out to obtain the fundamental data for development of digestibility and quality enhanced product of soy yogurt. Soy yogurt was processed from raw materials of soybean, defatted soybean and sprouted soybean which inoculated with Lactobacillus acidophilus and Bifidobacterium bifidum as a starter. Changes of chemical compositions, viable cell count and saccharides during processing were investigated including acceptibility of manufactured products. The results were summarized as follows; 1. Defatted soy milk ferment ed with Lactobacillus acidophilus was showed the greatest initial acid productivity and sprouted soy milk was showed the greatest growth of Loctobacillus acidophilus. 2. Acid production was accelerated when 2% glucose was used in soy milk. 3. Addition of reconstituted skim milk in soy milk and defatted roy milk increased acid production but was not showed the effect in the sprouted soy milk. 4. Sprouting soybean, the contents of raffinose and stachyose were decreased but those of glucose was increased. 5. When soy milk was fermented with Lactobacillus acidophilus. the contents of raffinose and stachyose were decreased. 6. As a result of panel test, sprouted soy yogurt which was produced by addition of reconstituted skim milk of 10% showed the greatest flavor and tastes.

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

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.843-850
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• 2016

This study was conducted to investigate changes in isoflavone composition (glycosides and bio-active aglycones) and evaluate the quality characteristics of doenjang prepared using different Bacillus strains (KACC15935 and HJ18-9). After 60 days of fermentation, ${\beta}-glucosidase$ activity of doenjang fermented with B. subtilis HJ18-9 was higher than those of other samples. Contents of aglycones (daidzein, genistein, and glycitein) in B. subtilis HJ18-9 significantly increased up to $703.90{\pm}11.09{\mu}g/g$. In addition, total phenolic content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity increased markedly during fermentation. These results suggest that fermentation with B. subtilis could be used to increase ${\beta}-glucosidase$ activity with a view towards development of functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.702-710
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• 2016

The bioactivity of soy grits cheonggukjang was enhanced by fermentation using three ${\beta}$-glucosidase-producing Bacillus subtilis strains (HJ 18-9, HJ 25-8, and HJ 18-9+HJ 25-8) for 48 h at $37^{\circ}C$. The results indicate that protease, cellulase, and a-amylase activities significantly increased (P<0.05) with increasing fermentation time. In addition, the amino-type nitrogen content of B. subtilis-fermented soy grits cheonggukjang increased to 91.0~168.0 mg% after 48 h of fermentation. Among the isoflavones in soy grits cheonggukjang, contents of ${\beta}$-glucosides or acetyl-glucosides were reduced while aglycone content increased upon fermentation. In particular, soy grits cheonggukjang fermented with B. subtilis HJ18-9 and HJ25-8 showed the largest increases in aglycone content compared to complex treatment. These results provide useful information for development starter (single and complex) as well as for production of high quality fermented soybean food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.75-80
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• 2002

The growth inhibition by nisin-Producing lactococci against Bacillus subtilis and its application to doenjang fermentation were investigated. Lactococcus lactis subsp. lactis IFO 12007, L. lactis subsp. lactis ATCC 7962 and L. lactis subsp. lactis ATCC 11454 were used as nisin-producing lactococci. All of three strain rapidly proliferated to more than 10$^{9}$ CFU/g in steamed soybeans. Only L. lactis subsp. lactis IFO 12007 was in steamed soybean without any pH decrease. In spite of the mild decrease in pH, the growth of B. subtilis was completely inhibited; no living cells were detected in a soybean sample inoculated with 10$^{6}$ CFU/g and incubated for 24 to 72h. The L. lactis subsp. lactis IFO 12007 was applied to doenjang fermentation as a starter culture. It produced high nisin activity in steamed soybean, resulting in the complete growth inhibition of B. subtilis, which had been inoculated at the beginning of the meju fermentation, throughout the process of doenjang production. Over-acidification, which is undesirable for doenjang quality, was successfully prevented simply by adding salt which killed the salt-intolerant L. lactis subsp. lactis IFO 12007. Furthermore, the nisin activity in doenjang disappeared with aging.