• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.9-22
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• 1994

The changes of the time-dependent accumulation of isoflavone aglycones(daidzein, genistein) and their glucosides(daidzin, genistin) by various stress-inducing treatment on cotyledon of soybeans(Dankyungkong and Paldalkong) were investigated. Levels of isoflavone aglycones and their glucosides in soybeans treated with UDP-glucose, $MgSO_4$ and $HgCl_2$ and infected with phytopathogen appeared to be higher than those of treatment with distilled water. When compared with data for control, the levels of isoflavone glucosides in citrate-treated soybeans were increased but those of their aglycones did not appear appreciable differences. In Paldalkong treated with UDP-glucose, $MgSO_4$ and $HgCl_2$ the levels of isoflavone aglycones and their glucosides were higher than in Dankyungkong. In particular, the accumulation of daidzein in Paldalkong was significantly higher than in Dankyungkong. By infection with Botrytis cinerea, the maximum amount of accumulation of daidzein in two cultivar did not to be a large different, but accumulation time appeared more rapidly in Paldalkong than Dankyungkong. The accumulation amount of daidzein and genistein in Dankyungkong treated with elicitors appeared to be similar at initial stage, but the level of daidzein after 48hours appeared to be higher than that of genistein. In Paldalkong, the level of daidzein was higher than that of genistein at all stage. The level of daidzein in soybeans infected with phytopathogen appeared to be higher than that of genestein.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1405-1409
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• 1999

This study was conducted to investigate the isoflavone contents of soybeans, Meju, and Doenjang. $The\;{\beta}-glucosidase$ activities were also determined and characterized in soybeans, Meju, and Doenjang. The total concentration of daidzein was 406 mg/kg of soybeans, 433 mg/kg of Meju, and 538 mg/kg of Doenjang. Aglycones compose 26.03% of total isoflavones in soybeans, 61.96% in Meju, and 107.68% in Doenjang. The total concentration of genistein was 484, 200 and 538 mg/kg of soybeans, Meju and Doenjang, respectively. Aglycones compose 19.49% of total isoflavones in soybeans, 68.52% in Meju, and 85.26% in Doenjang. The ${\beta}-glucosidase$ activity was detected in soybeans (5.65 units/mg protein), Meju (2.04 units/mg protein), and Doenjang (0.69 units/mg protein). The optimal pH of ${\beta}-glucosidase$ activities were $6.5{\sim}7.0$ and the optimal temperature of ${\beta}-glucosidase$ activities was $50^{\circ}C$.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.157-167
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• 2016

The changes of total phenolic and isoflavone contents and antioxidant activities in of brown soymilk fermented by Lactobacillus plantarum P1201 were investigated. The brown soymilk proliferated the cell growth and reached about 11.55log cfu/g after fermentation for 60hr, while pH and titratable acidity ranged from 6.25 to 4.03 and 0.18% to 1.03%, respectively. The total phenolic contents of brown soymilk slightly increased from 2.87mg/g to 2.98mg/g after fermentation for 60hr. The levels of isoflavone-glycosides and -malonylglycosides decreased, while the isoflavone-aglycone contents increased during fermentation of brown soymilk. In particular, the isoflavone contents was 38.30㎍/g, but increased the highest value of 84.31㎍/g after fermentation for 60hr. After then, it was slightly decreased after 60hr of fermentation. In addition, the levels of daidzein, glycitein and genistein among isoflavone aglycones were 24.12㎍/g, 25.25㎍/g and 24.71 ㎍/g, after fermentation for 36hr. The DPPH and ABTS radical scavenging activities and FRAP assay showed to be slightly increased during lactic acid fermentation of brown soymilk.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.442-445
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• 2008

Meju, a major ingredient of doenjang which is a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in natural environment in which steamed soy was exposed to airborne microorganism, in particular, fungi. Total isoflavone content was reduced from 1,849 mg/kg of cooked soy to 816 mg/kg of meju at the $90^{th}$ day of fermentation. Total glycosides and aglycones of isoflavones in meju were 1,827 and 22 mg/kg at 0 day and changed into 487 and 329 mg/kg at the 90th day of fermentation, respectively. Meanwhile, the ratio of glycosides to aglycones of isoflavones was not changed during aging of doenjang but remained relatively constant with 592 and 644 mg/kg aglycones at the 0 and $160^{th}$ day, respectively. When cooked soy was fermented with Aspergillus oryzae and Aspergillus flavus, isoflavone profiles were significantly different from each other while A. oryzae caused more extensive metabolism of isoflavones than A. flavus.

• KSBB Journal
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• v.16 no.2
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• pp.174-178
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• 2001

Soybeans contain the phytoestrogens genistein and daidzein, their glucosides genistin and daidzin and coumesterol. These isoflavonoid compounds are capable of producing an estrogenic response in a number of diverse species. This study determined optimum conditions for the extraction of the main isoflavones(daidzin, genistin, daidzein, genistein) in defatted soybean meal using high-performance liquid chromatography. The best optimum extraction was achieved at 75% ethanol, $80^{circ}C$, pH4 and a three hour contact time. In addition, isoflavones with high purity were separated by adding up to 4%(w/v) of calcium chloride dihydrate. Most soybean extracts were composed of $beta$-glucosidic conjugate(daidzin, genistin) which is difficult to adsorb in body. Therefore, $beta$-glucosidase was used to convert as conjugate to aglycone form (daidzein, genistein) which is easy to adsorb. The optimal conditions of enzyme reaction involved to be 8.4 units of enzyme concentration, pH5.0, $40^{circ}C$ and 40 minutes.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.229-235
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• 2004

Chemical composition, total dietary fiber(TDF), oligosaccharide, isoflavone and phytic acid contents of seven domestic and three imported soybean cultivars were determined. TDF contents were ranged from 16.83 to 21.71％(w/w) without remarkable differences among soybean cultivars. Phytic acid contents of domestic cultivars such as Geomjongkong 1 (3.02％) and Dawonkong (2.92％) were higher than imported ones such as Canadian (2.07％) and American (2.22％) soybeans for soybean sprout and US No. 1 (2.16％). The phytic acid contents of cotyledon parts were 1.5 to 2 times higher than those of hypocotyl parts. Isoflavone contents in whole seed were wide ranged from 371 to 2,398 $\mu\textrm{g}$/g among cultivars and it were existed mainly as glucoside isomers. Profiles of isoflavone aglycones were composed of 52％ genistein, 36％ daidzein and 11％ glycitein. Hwanggumkong, Dawonkong, Geomjongkong 1 and American soybean for sprout contained lower isoflavone than others. Hypocotyl parts of soybeans contained from 6120.1 to 16921.1 $\mu\textrm{g}$/g isoflavone with ratio of 48％ glycitein, 35％ daidzein and 10％ genistein. Isoflavone contents of cotyledon parts were ranged 375-2393 $\mu\textrm{g}$/g, composition of which had no glycitein, 55％ genistein and 38％ daidzein. Oligosaccharide contents were similar among cultivars. Stachyose of 3.0-3.9％, raffinose of 0.8-1.2％, sucrose of 4.5-7.8％ and fructose of 0.3-0.8％ were determined.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1952-1960
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• 2017

Recently, soybean isoflavone aglycones (i.e., daidzein and genistein) and ${\gamma}-aminobutyric$ acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides (i.e., daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. Lactobacillus brevis GABA 100 and Aspergillus oryzae KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and $59{\mu}g/g$, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell L. brevis GABA 100 and A. oryzae KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.294-298
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• 2009

Distribution of isoflavones and fatty acids in soymilk fermented with 7 Lactobacilli (L-type), 7 Bifidobacteria (B-type), or 5 Streptococci (S-type) were monitored. Total isoflavones in fermented soymilk ranged from 5.24 to $8.59{\mu}mol/g$ dry basis while those in unfermented soymilk were $8.06{\mu}mol/g$ dry basis. Depending on the types of inoculated microorganisms, fermented soymilk showed different profiles in isoflavones, especially aglycones and $\beta$-glucosides. Four L-type fermented soymilk had significantly higher aglycone content (33.69-46.21%) and low $\beta$-glucosides compared to control (p<0.05). All B-type fermented soymilk showed significantly high aglycone levels (p<0.05). Out of 5 Streptococci, 4 strains produced over 82.2% aglycones. Lipid content ranged from 162 to 224 mg/g and linoleic acid was the highest, followed by oleic, linolenic, palmitic, and stearic acids. Average ratio of unsaturated to saturated fatty acids in control, L-, B-, and S-type fermented soymilks was 6.30, 6.09, 6.30, and 5.94, respectively. This study can help to develop a fermented soymilk containing high isoflavone aglycones and low fat content.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.745-750
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• 1998

Soybean isoflavones known as an anticarcinogenic factor were evaluated in some Korean soybean foods by high performance liquid chromatography. Unfermented soybean foods contained predominantly isoflavone ${\beta}-glycosides$ (genistin and daidzin), but in the fermented soybean foods isoflavones were present mainly as aglycones (genistein and daidzein). Average contents of isoflavones of tofu, soymilk and soy sprout were 1, 151, 676 and 424 mg/kg, respectively. Among the fermented soybean products, soybean paste (Chongkukjang) was highest in the isoflavone content (920 mg/kg) and the degree of hydrolysis of ${\beta}-glycosidic$ bonds was ranged from 30 to 100%. Doenjang, Chunjang and Kanjang contained lesser amounts of isoflavones and their contents were 627, 291 and 10 mg/kg, respectively. Korean traditional fermented foods, Chongkukjang and Doenjang could be regarded as the excellent sources of soy isoflavone aglycones.

• The Korean Journal of Food And Nutrition
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• v.36 no.2
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• pp.87-92
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• 2023

Isoflavones found in soybeans are present as glycosides and aglycones, which differ according to their chemical structure. The absorption rate and bioavailability of aglycones are greater than those of glycosides. It is known that aglycone isoflavones in soybean was converted from glycoside isoflavones by activating of endogenous β-glucosidase under drying (40~60℃) conditions after soaking. In this study, we compared and analyzed the proximate composition and isoflavone contents of soybean powders prepared under dried after soaking were analyzed. In the comparison of the proximate compositions, the moisture contents of white soybean powder dried after soaking (WSPDS) and black soybean powder dried after soaking (BSPDS) were decreased as compared with those of the control white soybean powder (CWSP) and control black soybean powder (CBSP). Whereas the contents of other proximate compositions were increased. The aglycone isoflavone contents were higher in WSPDS than in CWSP. Whereas the aglycone isoflavone contents of BSPDS had a similar content those of CBSP because of the component characteristics of black soybean. In conclusion, we believe that it is appropriate to identify and utilize the component characteristics of soybean varieties in order to induce an increase in the functional component content of soybeans under drying conditions after soaking.