• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.245-250
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• 2003

Composition of isoflavone in cotyledon and hypocotyl of soybean were detected using HPLC. Optimum conditions for extracting isoflavone from hypocotyl were studied as well. Contents of isoflavone in soybean cotyledon and hypocotyl were 482.5 mg 100 $g^{-1}$ and 3453.3 mg 100 100 $g^{-1}$, respectively. Hypocotyl contained 7~8 times move isoflavone than corresponding cotyledon of the soybean. Malonyl glycoside accounted for move than 70% of the total isoflavone, followed by glycoside, acetyl glycoside, and aglycone. Aqueous ethanol of 60~80% was the most suitable solvent for extracting isoflavone from the hypocotyl. Optimum temperature and time was $90^{\circ}C$, 1hr. Acetic acid, NaCl, and NaOH added to 80% ethanol suppressed extraction yield of the phytochemieal.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1048-1050
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• 2011

• Food Science of Animal Resources
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• v.27 no.3
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• pp.329-336
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• 2007

This study was designed to find the optimum conditions for converting isoflavone glycoside to aglycone by ${\beta}-galactosidase$. Three different forms of the enzyme were tested and the optimum enzyme concentration, incubation temperature, pH, and incubation time were determined. Before treatment with enzyme, isoflavone contained 89.4% glycoside including daidzin, glycitin and genistin, and only 10.6% aglycone including daidzein, glycitein and genistein. Among the enzymes tested, the highest rate of isoflavone hydrolysis to aglycone, 35%, was observed when 3 unit/g Fungal Lactase (Amano Enzyme) was used. Higher incubation temperatures resulted in a higher rate of hydrolysis along with a greater loss of isoflavone mass. Therefore, body temperature $(37^{\circ}C)$ may be adequate for isoflavone conversion, with 44.9% hydrolysis and less than 10% loss of mass. As expected, a higher amount of aglycone was produced at pH 7 compared with other pH values. During 5hr of incubation, the conversion of glycoside to aglycone increased dramatically from 0 to 1hr, and plateaued thereafter. In addition, commercial soy-based milk was hydrolyzed more effectively with ${\beta}-galactosidase$ when incubated for 5hr. Based on the above results, the optimum conditions for isoflavone hydrolysis by ${\beta}-galactosidase$ were for 3 hr at $37^{\circ}C$, pH 7 with 3 unit/g Fungal Lactase (Amano Lactase), yielding an average total amount of aglycone ranging from 40 to 47%.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.163-169
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• 2009

A total of 155 microbial strains were isolated from the Korean traditional soybean paste based on their morphological features on the growth of agar plate. Among the isolated strains, a total of 28 strains were capable of hydrolyzing isoflavone glycoside to isoflavone aglycone efficiently in the soybean paste. Finally, two strains, K123-1 and SI, were selected because of their resistance to 15% NaCl and ability to convert isoflavone glycoside to isoflavone aglycone efficiently during the fermentation of soybean paste. The isolated strains K123-1 and SI were identified to be Pichia guilliermondii and Candida fermentati, respectively, using the partial 26S rDNA sequence analysis and phylogenic analysis. Pichia guilliermondii K123-1 and Candida fermentati SI converted daidzin to daidzein up to 96% and 95%, respectively, and genistin to genistein up to 92% when soybean pastes were fermented at $30^{\circ}C$ for 20 days with a single isolated strain. Pichia guilliermondii K123-1 and Candida fermentati SI were able to grow in the presence of 15% NaCl on both liquid medium and agar plate. We think that Pichia guilliermondii K123-1 and Candida fermentati SI might be one of good candidates for making functional soybean paste because they are isolated from the Korean traditional soybean paste and have a good ability to convert isoflavone glycosides to isoflavone aglycones and a high salt tolerance.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.371-374
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• 2004

본 연구는 식물성 에스트로겐인 isoflavone 배당체의 ${\beta}-1,4\;glycoside$ 결합을 ${\beta}-galactosidase$로 분해하여 그 생리적 작용이 더욱 효과적인 aglycone화 하기 위한 조건을 연구하여 기능성식품개발에 응용토록 하는데 목적이 있다. 실험 결과, 모든 ${\beta}-galactosidase$가 ${\beta}-1,4\;glycoside$ 결합의 분해력이 인정되지는 않았으며, 분해 가능성이 인정된 효소를 선택하여 실험한 결과 효소의 함량이 증가함에 따라 aglycone의 성분비율이 증대된 반면, 그 손실률 또한 증대되었고 배양시간이 길수록 aglycone의 성분비율이 증가하였으나 배양초기에 급격한 증가율을 보였으며, pH6과 7, 8에서 유사한 정도의 증가율을 보였고, 온도가 증가함에 따라 aglycone 성분비율이 증가되었지만 $40^{\circ}C$이상에서는 그 손실률이 크게 증가하였다. 결과적으로 판단해 볼 때, isoflavone을 aglycone화 하는데 있어 인체 내 유사조건에서 aglycone의 증가율이 높았으며 최적의 조건과 많은 차이를 나타내지 않았고 그 손실률 또한 최소화된 결과를 나타내어 isofalvone을 적용한 기능성 유제품을 연구하는데 있어 긍정적인 가능성을 보였다.

• Food Science and Preservation
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• v.22 no.1
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• pp.119-128
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• 2015

In this study, the ${\beta}$-glucosidase activity and total phenolic and isoflavone contents and antioxidant activities during Cheonggukjang fermentation with bitter melon powder (BMP) were investigated and evaluation of the same was performed. The level of ${\beta}$-glucosidase activity was increased at 48 hr and decreased after 72 hr, and the total phenolic and isoflavone-malonylglycoside and aglycone contents increased, while the antioxidant activities increased, but the total isoflavone and isoflavone-glycoside contents decreased during the Cheonggukjang fermentation. In particular, the soybean with 5% BMP fermented at $37^{\circ}C$ for 72 hr displayed the highest antioxidant activities, among all the samples. The highest levels of total phenolic and daidzein contents and DPPH radical scavenging activity, ABTS radical scavenging activity and FRAP assay results after 72 hr fermentation in Cheonggukjang with 5% BMP were found to be 13.5 mg/g, $390.57{\mu}g/g$, 90.74%, 99.79%, and 1.705 (OD593 nm) respectively. In addition, the more BMP was added to the Cheoggukjang, the more the off-odor of the Cheonggukjang decreased. These results suggest that BMP can be used to come up with a new type of Cheonggukjang with improved palatability and antioxidant activity.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3863-3866
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• 2013

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.391-397
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• 2013

Changes in ${\beta}$-glycosidase activity, total phenolic and isoflavone contents, and antioxidant activities during the fermentation of Korean black soybeans (Seoritae and Seomoktae) fermented food cheonggukjang by the potential probiotic Bacillus subtilis CSY191 were investigated. The levels of total phenolic and isoflavone-malonylglycoside and -aglycone contents increased, while 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity and ferric reducing/antioxidant power (FRAP) increased, but the isoflavone-glycoside contents decreased after cheonggukjang fermentation. The content of antioxidant compounds, including isoflavone-aglycones and -malonylglycosides, was increased by fermenting-processing, whereas the content of isoflavone-glycosides was decreased in the fermented soybeans. In particular, the Seoritae soybean fermented at 3 $7^{\circ}C$ for 48 h displayed the highest antioxidant activities, compared to those of the Seomoktae soybean and the fermented. The highest levels of daidzein, glycitein, and genistein were present at concentrations of 253.0 ${\mu}g/g$, 72.5 ${\mu}g/g$, and 114.1 ${\mu}g/g$ after 48 h of Seoritae soybean fermentation. From those results, we suggest that the high antioxidant activity of cheonggukjang of black soybeans might be related to the markedly higher levels of total phenolic and isoflavone-aglycone and -malonylglycoside contents achieved during fermentation.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.544-546
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• 2004

Phytochemical investigation of the whole plants of Grata/aria sessiliflora L. led to the isolation of four flavonoids. The structures of these compounds were identified as 2',4',5,7-tetrahydroxy-isoflavone (1), 2',4',7-trihydroxyisoflavone (2), 4',7-dihydroxyflavone (3), and isovitexin (4) using spectroscopic analysis. Among these, compounds 2, and 3 have not been reported from Crotalaria species, whereas compounds 1, and 4 were reported from this plant for the first time.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.5
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• pp.641-645
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• 2014

This study was performed to investigate the possibility of using three commercial bifidobacteria as a starter for soybean paste fermentation. In order to determine susceptibility to inhibition by high concentrations of salt in soybean paste, cell growth of three strains in sterilized soybean paste was analyzed. Bifidobacterium breve KCTC 5081 was the most resistant to salt, whereas Bifidobacterium bifidum KCTC 5082 showed low cell viability. Conversion efficiencies from glycoside isoflavone to aglycon isoflavone in soybean paste ranged from 11.3~28.6%, with Bifidobacterium longum KCTC 5734 the best strain. Therefore, B. longum KCTC 5734 may be used as a starter for Cheonggukjang fermentation, which is low-salt fermented soybean paste.