• The Plant Pathology Journal
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• v.33 no.5
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• pp.478-487
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• 2017

Soybean is the most important legume crop in the world. Several diseases in soybean lead to serious yield losses in major soybean-producing countries. Moreover, soybean can be infected by diverse viruses. Recently, we carried out a large-scale screening to identify viruses infecting soybean using available soybean transcriptome data. Of the screened transcriptomes, a soybean transcriptome for soybean seed development analysis contains several virus-associated sequences. In this study, we identified five viruses, including soybean mosaic virus (SMV), infecting soybean by de novo transcriptome assembly followed by blast search. We assembled a nearly complete consensus genome sequence of SMV China using transcriptome data. Based on phylogenetic analysis, the consensus genome sequence of SMV China was closely related to SMV isolates from South Korea. We examined single nucleotide variations (SNVs) for SMVs in the soybean seed transcriptome revealing 780 SNVs, which were evenly distributed on the SMV genome. Four SNVs, C-U, U-C, A-G, and G-A, were frequently identified. This result demonstrated the quasispecies variation of the SMV genome. Taken together, this study carried out bioinformatics analyses to identify viruses using soybean transcriptome data. In addition, we demonstrated the application of soybean transcriptome data for virus genome assembly and SNV analysis.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.50-56
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• 2001

Thirty-three bacterial and fungal strains were isolated from the rotten soybeans and soybean sprouts to isolate pathogenic microorganisms which cause soybean sprouts rot during soybean sprouts cultivation. In pathogenicity tests of the isolates on soybean sprouts, two isolates(K-17 and K-28) caused soybean sprouts rot and were identified as Erwinia carotovora and Fusarium sp., respectively. To isolate antagonists aganist K-17 and K-28 pathogens, bacteria were isolated from various soybean-cultivated soils and screened by the inhibition zone method. A bacterial isolate(J-232) which inhibited growth of both pathogens was identified as Pseudomonas fluorescens and further examined. The culture filtrate of P. fluorescens J-232 (dilution rate of 500 times) inhibited the growth of Erwinia carotovora K-17 and Fusarium sp. K-28 both on potato dextrose agar medium and on soybean sprouts cultivated in vessel. The development of soybean sprouts rots was observed during cultivation by inoculation of soybean seeds with culture filtrate of both pathogens. The combined inoculation of soybean seeds with culture filtrate of antagonistic bacterium and that of pathogens prevented soybean sprouts rot, and the growth of soybean sprouts was similar to that of control. The soybean sprouts inoculated with antagonists culture filtrate alone did not develop soybean sprouts rot, and the growth of the seedlings was shown to be slightly promoted as compared with that of control.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.363-368
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• 1990

As a work on the investigation of the processing aptitude of the Korean soybean cultivars, the soybean curd was made from 19 Korean soybean cultivars on a laboratory scale. The yield, proximate composition and rheological and organoleptic property of the resultant soygean curd were analyzed. The yields of soybean curd were ranged from 262.33% to 311.63%, being positively correlated with the soluble protein contents of the recommended soybean cultivars (r=0.9621). The recovery rate of protein in Baekun and Yeunha to the soybean curd was 72.94%, 70.62%, respectively. More than 80% of lipid in soybeans of Yeunha, Dankyung, Danyeob was transferred to the soybean curd. Lightness of the soybean curd made from Baekun, Kwanggyo, Saeal, Hill was higher than that of the others. The mechanical hardness of the soybean curd was strongly correlated with the final moisture content of the soybean curd (r =-0.8312), but not with the protein content of the soybean (r=0.1848). In the organoleptic test for color, texture, flavor and overall preference of the resultant soybean curd, the quality of Dankyung, Namcheon, S-138, Baekun was evaluated highly.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.441-449
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• 2010

The objective of this study was to investigate the physicochemical characteristics of soybeans cultivated in different regions and the accompanying soybean curd properties. To produce soybeans with regional competitiveness and demonstrate the distinctiveness of the soybean product, four regions(Paju, Andong, Muju, Hadong) and four varieties of soybean(Daewonkong, Daepungkong, Seonyukong, Cheogja 2) were selected for these experiments. There was a significant difference in the isoflavone content of soybeans and soybean curds(p<0.05). Soybeans from Andong had the highest content of genistein, daidzein and total isoflavone and soybeans from Hadong had the lowest content of these compound. Fatty acid composition of soybeans demonstrated a significant difference according to region(p<0.05). In particular, soybeans grown under adverse environmental conditions, such as high temperature and low latitude, contained the highest composition of oleic acid and the lowest composition of linoleic acid and linolenic acid. Although fatty acid content of soybean curd had a third of the fatty acid concentration of soybean, the same characteristic was observed in the fatty acid composition of soybean curd. In addition, both soybean and soybean curd had more than 80% unsaturated fatty acids and 50% of the unsaturated fatty acid content was linoleic acid. In conclusion, these results demonstrate the significant difference of soybean and soybean curd originating from different regions and showed the transition of nutritional constituents from soybean to soybean curd as a function of environmental factors. Therefore, we must consider these factors when manufacturing soy products.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.702-707
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• 2011

The purpose of this study was to analyze the bioactive compounds of soybean snacks and to carry out a sensory evaluation of those variations which had various seasoning mixing ratio. Five soybean snacks were developed for these experiments. Proximate composition, the contents of total phenol compounds and isoflavone, and sensory characteristics of the soybean snacks were measured. There were significant differences in amounts of isoflavones and total phenolic compounds of soybean snacks($p$ <0.05). The seasoned soybean snacks had a higher level of daidzein and genistein contents than did control group. The total phenol compound contents of the control group was 210.3 mg gallic acid equivalents/100 g, whereas those for individual soybean snacks(A~E) were 152.3, 160.2, 162.4, 158.4 and 164.6 mg gallic acid equivalents/100 g, respectively. In sensory evaluation, there were significant differences($p$ <0.05) in taste, texture, and overall acceptability of the soybean snacks.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.44-55
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• 2016

Bacillus cereus is a gram-positive, rod-shaped, spore-forming bacterium that has been isolated from contaminated fermented soybean food products and from the environment. B. cereus produces diarrheal and emetic toxins and has caused many outbreaks of foodborne diseases. In this study, we investigated whether B. amyloliquefaciens RD7-7, isolated from rice doenjang (Korean fermented soybean paste), a traditional Korean fermented soybean food, shows antimicrobial activity against B. cereus and regulates its toxin gene expression. B. amyloliquefaciens RD7-7 exhibited strong antibacterial activity against B. cereus and inhibited the expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM). We also found that addition of water extracts of soybean and buckwheat soksungjang (Korean fermented soybean paste made in a short time) fermented with B. amyloliquefaciens RD7-7 significantly reduced the growth and toxin expression of B. cereus. These results indicate that B. amyloliquefaciens RD7-7 could be used to control B. cereus growth and toxin production in the fermented soybean food industry. Our findings also provide a basis for the development of candidate biological control agents against B. cereus to improve the safety of fermented soybean food products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.980-985
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• 1994

We investigated the quality of soybean paste(Doenjang) fermented by BAcillus brevis. The results obtained were as follows : soybean paste fermented by Bacillus brevis had alkaline pH and yellow ochre color. Dextrinizing activity was about 98 D.P. unit from 5th to 25th day of fermentation at 3$0^{\circ}C$ and after that day somewhat decreased . Saccharifying activity was respectively 6.1, 7.2, 6.8, 6.4 S.P. unit on 5, 15, 25 and 35th day of fermentation. Protease activity suddenly increased after 15th day of fermentation and was 250, 275, 299 unit on15, 25, 35 th day of fermentation , respectively. The most abundant free amino acid was found to be glutamic acid (561.8mg%) in soybean paste fermented by Bacillus brevis. In case of free sugar and non-volatile organic acid, fructose and oxalic acid showed highest content of 10.25mg% on 25th day and 12.20mg% on 15th day. The contents of free amino acids, free sugars, organic acids in soybean paste fermented by B.brevis were most abundant after 25 days of fermentation and this results were similar to that of traditional soybean paste. The odor of soybean paste fermented by Bacillus brevis was improved to be a nice soybean paste odor on 25th day of fermentation. However, sensory evaluation value of the taste of it decreased after 10 th day of fermentation.

• Korean journal of food and cookery science
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• v.18 no.4
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• pp.381-389
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• 2002

The purpose of this study was to select an ingredient acting as a natural emulsifier to retard the retrogradation of rice cake by the measurement of mechanical characteristics of the cakes. For the purpose, Backsulgi, the most basic type of rice cake, was prepared by adding various ingredients having high contents of lecithin such as raw soybean powder, parched soybean powder, soybean oil, egg yolk powder, and the measurements and observations on the chromaticity, swelling power, pore ratio and cross-section were made. In addition, changes in the textural characteristics of Backsulgi samples were determined while storing them at the temperatures of 4$^{\circ}C$ and 20$^{\circ}C$ for 0, 1, 2 and 3 days. The results of the study were as follows: 1. In terms of chromaticity, the Backsulgi samples added with egg yolk powder, raw soybean flour and parched soybean flour were higher in yellowness(b) than the controls. 2. Both swelling power and pore ratio of Backsulgies added with raw soybean flour were higher than those of controls. 3. A cross-sectional observation using an electron microscope indicated that rice flour particles of controls had uneven pores and were conglomerated in a large lump while Backsulgi samples of raw soybean flour or roasted soybean flour had large and even pores and showed loosened bonding to be transformed into a sponge shape. 4. In hardness, Backsulgi samples added with raw soybean flour had less changes in hardness than that of controls, indicating that the effect of retarding retrogradation was higher when the storage time got longer.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.426-433
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• 2007

We analyzed the isoflavone content of domestic soybeans during steaming, boiling, fermentation, germinating cultivation, fermentation, and soybean curd production. The isoflavone content of the beans was reduced by steaming and boiling, and overall reductions ranging from 16.0 to 65.0% of initial isoflavone values were detected. After 4 days of germinating cultivation, the total isoflavones of Eunhakong increased from 1,341 to $2,017\;{\mu}g/g$ and the total isoflavones of Guinunikong increased from 1,284 to $1,535\;{\mu}g/g$. The isoflavone content of the vinegar beans produced from Hwangkeumkong and Black No.1 increased from 1,877 to $1,956\;{\mu}g/g$, and from 885 to $1,956\;{\mu}g/g$ after 8 days of immersion in 4% acetic acid, respectively. During soybean curd production, significant amounts of isoflavones were lost in the whey (30-31 %) and soybean curd residue (15-20%). Only 37.4% of the isoflavones present in the original soybeans remained in the soybean curd with the hot extraction method, and 50.7% of them with the cold extraction method. Soybean curd prepared with whole soybean method, however, retained 80.7% of the initial isoflavones.

• Korean journal of food and cookery science
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• v.22 no.4 s.94
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• pp.545-551
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• 2006

The effects of the addition of germinated soybean powder on Injulmi characteristics were investigated in this study. Injulmi was prepared with five different levels of germinated soybean powder (0%, 4%, 8%, 12% and 16%)and the physical properties were examined. The moisture content decreased, while the protein, fat and ash contents increased With increasing germinated soybean powder content. Total isoflavone contents, 3.39${\sim}$15.35 mg% before cooking, slightly increased to 3.94${\sim}$15.96 mg% after cooking. Genistin, genistein, daidzin and daidzein, which are blown to be the major functional isoflavones, accounted for approximately 93% of total isoflavone contents. The color of Injulmi darkened slightly and became greenish yellow with the addition of germinated soybean powder. Textural profile analysis showed that hardness and gumminess increased, but cohesiveness and springiness decreased with increasing germinated soybean powder level. Sensory test showed that Injulmi prepared with up to 8% added germinated soybean powder was evaluated as being equally acceptable as Injulmi without germinated soybean powder.