• 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.

• 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.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.245-255
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• 2018

The research was aimed to analyze the functional constituents (GABA and isoflavone), radical (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl) scavenging activities and enzyme (${\alpha}-glucosidase$ and lipase) inhibitory effects of soypowder milk (SPM) and fermented soy-powder milk (FSPM) with varied Lactobacillus brevis. Ten ${\gamma}-aminobutyric$ acid (GABA) producing lactic acid bacteria that showed 96-99% similarity with L. brevis, according to 16S rRNA gene sequence analysis, were isolated from fermented kimchi. The conversion rates of GABA were obtained 66.96-93.51, 63.76-84.58, and 57.05-69.75% in monosodium glutamate, gluten and soy protein, respectively. The levels of pH and glutamic acid of FSPM were found lower than those of SPM, but the acidity and GABA contents were higher. The GABA conversion rate of FSPM with BMK484 strain was attained the highest 69.97%. The contents of isoflavone glycoside ($1290.93{\mu}g/g$) was higher in SPM, but the content of isoflavone aglycone ($287.27-501.9{\mu}g/g$) was higher in FSPM. The levels of isoflavone aglycone such as daidzein, glycitein and genistein, were found as the highest 240.2, 61.24 and $200.45{\mu}g/g$, respectively, when FSPM was made with BMK484 strain. The DPPH, ABTS and hydroxyl radical scavenging and ${\alpha}-glucosidase$ and pancreatic lipase inhibitory activities of FSPM made with BMK484 strain were the relatively higher 60.31, 88.10, 61.25, 52.71, and 39.37%, respectively. Therefore, the L. brevis can be used as a material capable of simultaneously enhanced GABA and isoflavone aglycone in FSPM.

• Food Science and Preservation
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• v.25 no.1
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• pp.7-18
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• 2018

In this study, soy-powder yogurt (SPY) with enhanced levels of ${\gamma}$-aminobutyric acid (GABA) and isoflavone aglycone was produced from sprouting high-protein soybeans (HPSs). The fermented steam-HPS sprouts (0 to 4 cm) were fermented (72 h) with Lactobacillus brevis, and the total free amino acids (FAAs) of the formed mixtures were determined to be 79.53, 489.93, 877.55, 780.53, and 979.97 mg/100 mL in the fermented HPS (FHPS), and the fermented steam-HPS with 0 cm (FSHPS-0), 1 cm (FSHPS-1), 2 cm (FSHPS-2), and 4 cm sprouting lengths (FSHPS-4), respectively. The levels of glutamic acid (GA) and GABA were observed to be the highest, 100.31 and 101.60 mg/100 mL, respectively, in the unfermented HPS (UFSHPS-1, 1 cm) and FSHPS-1 sprouts, respectively. Moreover, the total contents of the isoflavone glycoside form decreased proportionally to the increasing total levels of isoflavone aglycones after fermentation in FSHPS-0, FSHPS-1, FSHPS-2, and FSHPS-4. The levels of isoflavone aglycones were detected as 350.34, 289.15, 361.61, 445.05, and $491.25{\mu}g/g$ in FHPS, FSHPS-0, FSHPS-1, FSHPS-2, and FSHPS-4, respectively. While FSHPS-1 exhibited the highest DPPH (63.28%) and ABTS (73.28%) radical scavenging activities, FSHPS-4 contained the highest isoflavone aglycone ratio (81.63%). All in all, the FSHPS-1 mixture prepared in this study exhibited high GABA content and functional prosperity, thereby making it suitable for potential applications in the soy-dairy industry.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.105-110
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• 2015

BACKGROUND: Soy isoflavones, structurally similar to endogenous estrogens, may affect human body through both hormonally mediated and non-hormonally related mechanisms. Heat processing could change chemical compositions. The effects of different thermal processes, boiling and HTHP(high temperature and high pressure) on the composition of isoflavone compounds and total amount of domestic soybeans were investigated in this study. METHOD AND RESULTS: Three different kinds of soybean samples were collected from RDA-Genebank. The samples were extracted using methanol, distilled water, and formic acid based solvent. Also the same solvents were used for mobile phase in UPLC/ToF/MS. All of the isoflavone compounds were analyzed based on the aglycone type of external standard for quantification. The standard calibration curve presented linearity with the correlation coefficient R2 > 0.98, analysed from 1 to 50 ppm concentration. The total isoflavone contents does not change by treatment within the same breed. While "boiling" and "HTHP" processes tend to increase the contents of aglycone and ${beta}$-glucosides, "fresh" soybeans retained the high concentration of malonylglucosides. CONCLUSION: These results have to be considered while developing an effective functional food, from the health while point of view using soybeans.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.117-123
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• 2016

Bioconversion of aglycone-formed isoflavones from glycoside-formed isoflavones by commercial lactic acid bacteria in fermented soybean paste was evaluated. Enterococcus faecium KCTC 13410 showed the most resistant capacity and Lactobacillus acidophilus KCTC 3925 had a sensitive susceptibility at a high NaCl concentration (13.2%) in fermented soybean paste. Among the 5 strains tested, Lac. acidophilus KCTC 3925 showed the highest relative ratio of aglycone-formed isoflavones to total isoflavones in fermented soybean paste. Production of exopolysaccarides (EPS) by lactic acid bacteria was compared using de Man, Rogosa, and Sharpe medium containing 1% sucrose at $37^{\circ}C$ for 48 h. Among the 5 lactic acid bacteria, Lac. acidophilus KCTC 3925 and Lactobacillus rhamnosus KCTC 3929 were investigated to produce EPS. Based on the results concerning growing susceptibility and conversion of aglycone-formed isoflavones/EPS production, it is anticipated that Lac. acidophilus KCTC 3925 may be used for preparation of Cheonggukjang, which contains relative low NaCl content.

• Korean journal of food and cookery science
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• v.32 no.2
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• pp.197-203
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• 2016

Purpose: In this study, small black beans (Rhynchosia nulubilis) that were produced in the Jungsun province of South Korea were selected for use in various cooking recipes because they are known to contain higher isoflavones and excellent antioxidant effects, as compared to any other domestic soybeans. Methods: Physicochemical and antioxidant characteristics of small black beans were analyzed with uncooked beans and four other cooking methods of pan broiling, boiling, steaming, and pressure cooking. Results: Contents of ${\beta}$-glucosides (daidzin, glycitin, and genistin) and aglycone (daidzein, glycitein, and genistein) in small black beans were significantly different depending on the cooking methods (p<0.001). The results of the experiment indicated that the amount of total polyphenol in pressure cooked beans was highest, showing a value of 7.16 mg/g (p<0.001). Most contents of isoflavones (${\beta}$-glucoside, aglycone) in uncooked beans appeared to increase after cooking. In particular, the amount of glycitein was highest in pan broiled beans ($9.63{\mu}g/g$). The total isoflavone content differed among the different cooking methods, ranging from highest to lowest in the following order : pan broiled beans ($759.49{\mu}g/g$), pressure cooked beans ($725.12{\mu}g/g$), boiled beans ($591.05{\mu}g/g$), steamed beans ($511.61{\mu}g/g$), and uncooked beans ($180.80{\mu}g/g$) (p<0.001). Conclusion: Especially, the amount of isoflavones increased significantly in pan broiled beans and pressure cooked beans, suggestive of optimized cooking methods for increasing nutritional and functional contents in cooked food.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.96-102
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• 2002

The levels of biologically active compounds, such as isoflavone, total saponin, dietary fiber, soy oligosaccharides, and lecithin from each serving size of commercial soy products, were quantitatively determined from the raw soybean, soymilk, tofu, isolated soy protein (ISP), soybean paste(toenjang), natto, and tempeh from local and foreign market. Soy flour, natto, and soymilk contained 489.1 mg, 308.3 mg, and 138.1 mg of isoflavone in each 100 g of dry matter, respectively. The ratios of aglycone to glucoside of soybean paste and tempeh showed relatively high level compared with other tested soy products. Commercial soymilk showed the highest ratio of soluble fiber to total dietary(59%). The higher levels of dietary fiber (20.1 g) and lecithin (1.13 g) were also found in tofu. The lecithin and saponin content of isolated soy protein(ISP) were highest (0.63 g and 0.65 g/ 100 g of dry matter) among the tested samples. In conclusion, soy flour showed the highest level of biologically active compounds, such as saponin, isoflavone, dietary fiber, and soy oligosaccharides. But when the evaluation was based on the serving size, soymilk containing 31.5 mg of isoflavone, 2.59 g of dietary fiber, 0.57 g of oligosaccharides, 0.10 g of lecithin, and 0.11 g of saponin showed similarity to those of the tested soybeans(20 g).

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.62-71
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• 2016

BACKGROUND: Soybeans are the rich sources of isoflavones. To date, the changes of isoflavone contents in various black soybeans cheonggukjang during fermentation by Bacillus subtilis CSY191 has not been investigated.METHODS AND RESULTS: This study investigated the changes of total phenolic and isoflavone contents and antioxidant effects during cheonggukjang fermentation made with four black soybean (BS) cultivars including Cheongja, Cheongja#3, Geomjeong#5, and Ilpumgeomjeong with a potential probiotic Bacillus subtilis CSY191. The total phenolic contents, isoflavone-malonylglycoside and -aglycone contents, and antioxidant activity were increased in cheonggukjang at 48 h fermentation, while the content of isoflavone-glycosides was decreased during cheonggukjang fermentation. In particular, the Cheongja#3 soybean fermented at 37℃ for 48 h displayed the highest antioxidant activities, compared to those of the other BS cultivars tested. Also, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 17.28 mg/g, 283.7 g/g, 39.9 g/g, and 13.2 g/g at the end of Cheongja#3 soybean fermentation.CONCLUSION: The results from this study suggested that the enhanced antioxidant activity of cheonggukjang of BS might be related to increased levels of total phenolic, isoflavon-aglycone, and malonyl-glycoside contents achieved during fermentation. Furthermore, fermented Cheongja#3 soybean showed the highest levels of enhanced antioxidant activities than the other BS cultivars.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.569-578
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• 2015

BACKGROUND/OBJECTIVES: Fermentation can increase functional compounds in fermented soybean products, thereby improving antioxidant and/or anti-inflammatory activities. We investigated the changes in the contents of phenolics and isoflavones, antioxidant activity and anti-inflammatory activity of Doenjang during fermentation and aging. MATERIALS/METHODS: Doenjang was made by inoculating Aspergillus oryzae and Bacillus licheniformis in soybeans, fermenting and aging for 1, 3, 6, 8, and 12 months (D1, D3, D6, D8, and D12). Doenjang was extracted using ethanol, and sequentially fractioned by hexane, dichloromethane (DM), ethylacetate (EA), n-butanol, and water. The contents of total phenolics, flavonoids and isoflavones, 2,2-diphenyl-1 picryl hydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) were measured. Anti-inflammatory effects in terms of nitric oxide (NO), prostaglandin (PG) E2 and pro-inflammatory cytokine production and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions were also measured using LPS-treated RAW 264.7 macrophages. RESULTS: Total phenolic and flavonoid contents showed a gradual increase during fermentation and 6 months of aging and were sustained thereafter. DPPH radical scavenging activity and FRAP were increased by fermentation. FRAP was further increased by aging, but DPPH radical scavenging activity was not. Total isoflavone and glycoside contents decreased during fermentation and the aging process, while aglycone content and its proportion increased up to 3 or 6 months of aging and then showed a slow decrease. DM and EA fractions of Doenjang showed much higher total phenolic and flavonoid contents, and DPPH radical scavenging activity than the others. At $100{\mu}g/mL$, DM and EA fractions of D12 showed strongly suppressed NO production to 55.6% and 52.5% of control, respectively, and PGE2 production to 25.0% and 28.3% of control with inhibition of iNOS or COX-2 protein expression in macrophages. CONCLUSIONS: Twelve month-aged Doenjang has potent antioxidant and anti-inflammatory activities with high levels of phenolics and isoflavone aglycones, and can be used as a beneficial food for human health.