• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.792-798
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• 1994

In order to investigate the antioxidant activity of phenolic compounds contained in domestic Meju and Doenjang , the methanolic extract from defatted Meju and Doenjang was fractionated into the phenolic acid and the isoflavone fractions by alumina column and polyamide-6 column chromatography, respectively. Both phenolic acid and isoflavone fractions exhibited an identical antioxidative effect against the oxidation of linoleic acid. GC analysis revealed that the phenolic acid fractio contained vanillic , chlorogenic ,p-coumalic , ferulic, and caffeine acid. The content of caffic acid was greater than 70% in the phenolic acid fraction and the content of vanillic and chlorogenic acids were disappeared during fermentation, and thus, the facts are thought to be reasons for the low antioxidant activity of the phenolic aicd fraction from Doenjang. Similarly, the isoflavone fraction cotained daidzin, glycitin-65-0 glucosider and genistin and their aglycons such as daidzein, glyciten and genistein. The content of daidzin and genistin in Meju dramatically decreased at the early stage of fermentation ,whereas the content of daidzein an dgenistein rather increased ; however, these change in isoflavone contents did not affect the antioxidant activity of isoflavone fractions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.383-389
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• 1997

Doenjang(fermented soybean paste) was prepared by the series of processes including soaking, cooking, first fermentation(3 days at 30$\pm$2$^{\circ}C$) for the preparation of meju(soybean koji) after inoclulation of Aspergillus oryzae, and further fermentation (60 days at 30$\pm$2$^{\circ}C$) for the ripening after addition of salt 13% to meju. the crude phenolics extracted from defatted soybean and doenjang were fractionated onto the neutral phenolics(isofavonoids) and acidic phenolics(phenolic acids), respectively. Composition and antioxidative characteristics of phenolic fractions were determined. The neutral phenolic fractions contained genistin, genistein and daidzein; on the other hand, acidic phenolic fractions had syringic acid and seven other components. The content of genistin in doenjang dramatically decreased at the early stage of fermentation, whereas the content of genistein rather increased. In addition, the content of syringic acid of acidic phenolic fractions were increased during fermentation. These changes in individual phenolic components affected the antioxidative activity of neutral phenolics or acidic phenolics. antioxidative activity of phenolic compounds were evaluated during soybean fermentation. The antioxidative and free radical scavenging activity of neutral phenolic fractions and acidic phenolic fractions on linoleic acid autoxidation were also investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.16-21
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• 2004

To assess the estrogenicities of Korean arrowroot (Pueraria thunbergiana) the contents of nine phytochemicals which are known to present were analyzed by HPLC. Also the estrogenecities of these phytochemicals were assayed using estrogen receptor dependent transcriptional expression assay. Daidzein and puerarin are major compounds in arrowroot, which were contained in the order of: root>stem>leaf>flower>seed. Among the assayed phytochemicals daidzein, genistein, biochanin A, formononetin, puerarin and genistin were highly estrogenic. The total estrogenicities in different parts of arrowroot and those by regions in Korea were also assessed. Roots had the highest estrogenic effects. The estrogenicities also were shown in stem and leaf. The differences in the estrogenicities of arrowroots by regions in Korea were shown. These results demonstrated that the estrogenic phytochemicals content was the highest in Korean arrowroot and also present in stem and leaf.

• Food Science and Preservation
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• v.15 no.4
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• pp.598-605
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• 2008

Korean traditional soy paste(Doenjang) was fermented for 90 days using, as a starter, a Meju prepared by inoculation of Bacillus subtilis cells. Changes in physiochemical and functional properties were investigated during fermentation. Amylase and protease activities increased and showed maximal levels(4.11 and 7.75 units/mL, respectively) after 60 days of fermentation. Both enzyme activities then fell. Inhibitory activities of the soy paste against tyrosinase and angiotensin converting enzyme(ACE) increased during the fermentation period. Antimutagenic activities during fermentation were determined using the S. enterica serovar Typhimurium TA100 and TA98 analysis system. No significant differences in activity were observed in soy pastes prepared with or without B. subtilis. Antimutagenic activities against the activities of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitro-O-phenylenediamine (NPD) increased and reached 70.33% and 60.22%, respectively, after 90 days of fermentation, as assessed using the tester strain TA100. Against the actions of NPD and 4-nitroquinoline-1-oxide(NQO), antimutagenic activities also increased during fermentation and reached 50.84% and 47.01%, respectively, as assessed using the tester strain TA98. The genistin content was much higher(187.48 g/g) in soy paste prepared using B. subtilis inoculation than the level(31.30 g/g) seen in soy paste prepared without bacterial inoculation, although the contents of daidzein and genistein were slightly reduced under such circumstances.

• Food Science and Preservation
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• v.15 no.5
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• pp.736-742
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• 2008

To evaluate changes in functional characteristics of traditional Doenjang during aging, Doenjang was prepared using an extract of Phellinus linteus (Phellinus extract). Control Doenjang was aged without the extract. The protease activity of Doenjang prepared with Phellinus extract was 3.15 units/mL. Tyrosinase and acetylcholinesterase inhibition activities were 45.78% and 55.18% of control, respectively, in the treated sample. When Salmonella enterica serovar Typhimurium TA100 was used as a reporter strain, antimutagenic activities against the mutagens MNNG and NPD were 90.42% and 82.57% of control values in the treated sample. When S. enterica serovar Typhimurium TA98 was used, antimutagenic activities were 60.28% and 50.33% of control, respectively. Hydrogen-donating activity was 86.65% in the treated sample, which was higher than that of the control (61.69%). Daidzin (an isoflavon glucoside) levels in Doenjang prepared with Phellinus extract were higher, by 35.49 mg/kg, than the control, whereas genistin was not detected in either group. Daidzin and genistin aglycone levels were 263.01 mg/kg and 262.60 mg/kg in the control and test groups, respectively.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.573-578
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• 2008

Lactobacillus paraplantarum KM (Lp), Weissella sp. 33 (Ws), and Enterococcus faecium 35 (Ef) were used in single (Lp, Ws, Ef) or mixed cultures (Lp+Ws, Lp+Ef, Ws+Ef) for soy milk fermentation ($37^{\circ}C$, 12 h). After 12 h, the cell numbers, pH, and TA of soymilk were $7.4{\times}10^8-6.0{\times}10^9CFU/ml$, 3.8-4.5, and 0.59-0.70%, respectively. Changes in the contents of glycitin and genistin in soymilk fermented with Ef were not significant. The contents of isoflavone glucosides in soymilk fermented with the other cultures decreased significantly with an increase of aglycone contents (p<0.05). It corresponded well with a sharp increase in ${\beta}$-glucosidase activity during fermentation. About 92-100% of the daidzin and 98-100% of the genistin in soymilk were converted to corresponding aglycones by Lp, Ws, or Lp+Ef within 12 h.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.231-236
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• 2007

The isoflavone distributions of soy samples treated with soaking, oven-drying, and almond additions were determined by high performance liquid chromatography (HPLC). Oven-drying was performed to increase the amount of ${\beta}-glucoside$ isoflavones, and almonds were added to convert the ${\beta}-glucosides$ into their corresponding aglycones. Oven-drying at $100^{\circ}C$ for 4 hr significantly increased ${\beta}-glucoside$ levels and decreased $malonyl-{\beta}-glucosides$, while almond additions of 2.5% and 5.0% (w/w) significantly increased aglycone contents (p<0.05) for samples with 12 hr of drying. The rate of increase for genistein from genistin was faster than that of daidzein from daidzin with almond additions. The ${\beta}-glucosidase$ activity in the 5.0% added almond soybean samples was significantly higher than in the samples without added almond (p<0.05). The aglycone content increased from 1.62% in the raw soybeans to 61.55% in the 2.5% added almond soybean samples for 12 hr of incubation. The information from this study could be used to increase the isoflavone aglycone contents of soybeans by using natural products such as almonds, without organic solvent additions or microorganism fermentation.

• Journal of Life Science
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• v.8 no.5
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• pp.473-478
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• 1998

The radical scavenging activity of the methanol extracts was in the order of doenjang〉 meju〉 soybean. The metha-nol extracts were further fractionated with dichloromethane, ethyl acetate, butanol and water in sequence. Among the solvent fractions of the methanol extracts, the ethyl acetate fraction demonstrated high levels of radical scave-nging activity. On the other hands, the nitrite scavenging activity of the methanol extrats was in the order of doen-jang〉soybean〉meju. All fractions from doenjang were exhibited the strong nitrite scavenging effect. Especially, $H_2O$, EtOAc and BuOH fractions with 6gmg/10$m\ell$ concentration exhibited much stronger nitrite scavenging effect than that of L-ascorbic acid. The ethyl acetate fraction showed remarkable antioxidant and nitrite scavenging effects compared with the other fractions obtained from soybean, meju and doenjang. The ethyl acetate fraction of doenjang was fur-ther purified by repeated chromoatograpic methods and isolated three compounds. There are identified as genistin, dai-dzein and genistein on the basis of spectral data.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.498-503
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• 2005

Stability of soybean isoflavone isomers according to extraction conditions such as temperature, pH, and extracting solvents was investigated. Heating induced three chemical reactions to occur for malony1 derivatives of isoflavones, namely decarboxylation of malony1 groups into acety1 derivatives, deesterification of malony1 residues, and hydrolysis of $\beta$-glycosidic bonds. Among the twelve isoflavone isomers, change in concentrations of acety1glycosides were most pronounced: Acety1 derivatives were present only in trace amounts in unheated hypocotyls, but the content increased dramatically during heating. As for the glycosides, concentrations of daidzin and glycitin increased due to heat treatment, though that of genistin remained almost unchanged. Heat decomposition rates and the patterns differed among the three malony1 derivatives. After 120 min at $80^{circ}C$, the relative concentrations of daidzin, glycitin and genistin were increased from $9.2\%$, $12.4\%$ and $3.3\%$ to $19.3\%$, $21.9\%$ and $6.2\%$, respectively. When crude isoflavones were solubilized in glycine buffer (pH 10.0) and incubated at $80^{circ}C$, deesterification occurred faster than at pH 7.0. When the pH of isoflavone solution was increased, the malony1glycosides were hydrolyzed to their respective glycosides at increased rate. Both acetyl and aglycone forms were unchanged and only de-esterification reactions occurred. At the acidic pH, malonylglycosides were much stable both at 60 and $80^{circ}C$. However at pH 10, $80^{circ}C$ and 1 hr, $75-80\%$ of malonylglycosides were transformed to their deesterified glycosides. When isoflavones were extracted with $60\%$ aqueous ethanol at $60^{circ}C$, isoflavone isomers were stable and the deesterification reactions did not occur in these conditions. However, at $80^{circ}C$ deesterification of malonyiglycosides occurred significantly with $15-20\%$ of malonylglycosides being hydrolyzed into their respective glycosides. This experiment showed that malonylglycosides undergo decomposition when heated or exposed to alkaline conditions. Also, aqueous ethanol was preferred to aqueous methanol as solubilizing media for obtaining extract with minimum degradation of malonylglycosides.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.24-27
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• 2006

A simple HPLC quantification method was developed for genistein, genistin, daidzein, and daidzin in soybeans and soybean products. The procedure used a $4.6{\times}100\;mm$ $Chromolith^{(R)}$ RP-18e column with a mobile phase of 1% HOAc in 20% MeOH to 1% HOAc in 80% MeOH for 10 min. The injection volume was $2\;{\mu}L$ at a flow rate of 2 mL/min. Detection was carried out under UV at 254 nm. Under these conditions, the major isoflavones daidzein, daidzin, genistein, and genistin in soybean and soybean pastes were eluted within 7 min with baseline separation. Optimal extraction of the above four major isoflavones was achieved when 40 g of soybean or soybean paste was refluxed in 100 mL of 95% ethanol for 2 hr. Ten different soybean cultivars and nine commercial soybean pastes were analyzed by this method. The total isoflavone content was highest in the cultivar Somyung ($2,497\;{\mu}g/g$ dry weight). The isoflavone content in soybean pastes varied widely from manufacturer to manufacturer (an almost five-fold difference between the highest and lowest values). Such variations were presumably due to differences in fermentation conditions, type of soybeans used, and levels of such additives as starch and salt.