• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.916-918
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• 2002

The effect of acid hydrolysis on isoflavone contents of defatted soybean flour (DSF) was investigated in this study. Isoflavone analyzed were daidzein, genistein, glycitein, daidzein, genistein and glycitein with using HPLC. The DSF suspension was heated at $95^{\circ}C$ for 4 hour with addition of HCl (0.25-3.00 N) and analyzed isoflavone. The results showed that the total isoflavone was increased as the HCl concentration increased up to 1.0 N HCl during heating, indicating conversion of glucoside isomers of isoflavone to its aglycons. However, higher concentration than 1.0 N HCl caused a relatively fast decrease in isoflavone after 4 hour of heating. These results were probably caused by degradation of isoflavone by high concentration of acid during heating. The glucosides of isoflavone were steadily decreased while its aglycons were rather increased during $1.0{\sim}2.0$ hour of heating.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1544-1552
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• 2007

The present study evaluated the effects of isoflavone-rich bean sprout on the lipid metabolism in ethanol-treated rats. Fifty male Sprague-Dawley rats were randomly divided into five groups: normal control, alcohol control, low soybean sprout+ethanol (low SS), high soybean sprout+ethanol (high SS) and isoflavone extract+ethanol (IE). They were fed experimental diets based on Lieber-DeCarli liquid diet for 40 days. Body weight, food intake and feed efficiency ratio (FER) of ethanol-treated groups were significantly suppressed compared with that of the normal control group. Among the ethanol-treated groups, high SS group showed in significant increase in the body weight, food intake and FER. Supplementation of isoflavone-rich soybean sprout powder or isoflavone extract significantly decreased plasma triglyceride (TG), total cholesterol (TC), atherogenic index (AI) and increased the ratio of HDL-cholesterol to TC. Supplements also significantly decreased total lipid, TG and TC in liver tissue compared with that of alcohol control. There was a significant decrease in hepatic lipid peroxidation products in IE group compared with other ethanol-treated groups. This results suggest that supplementation of isoflavone-rich bean sprout powder may exert beneficial effects on lipid metabolism in chronically alcohol-treated animals by improving lipid profiles in plasma and liver tissues.

• 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.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.

• 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.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.959-968
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• 2014

The changes in the ${\beta}$-glucosidase activity, total phenolic contents, isoflavone contents, and antioxidant activities during the fermentation of cheonggukjang by Bacillus amyloliquefaciens MJ1-4 with and without garlic were investigated. The levels of total phenolic and isoflavone-malonylglycoside, -acetylglycoside, and -aglycone contents increased, whereas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric reducing/antioxidant power (FRAP) assay results increased, but isoflavone-glycoside levels decreased during cheonggukjang fermentation. The levels of total phenolic and total isoflavone contents and the antioxidant activities were higher in cheonggukjang fermented without garlic (CFWOG) than in cheonggukjang fermented with garlic (CFWG) after 24 h of fermentation, but they were lower in CFWOG than in CFWG after 72 h of fermentation. In particular, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 15.18 mg/g, $264.4{\mu}g/g$, $16.4{\mu}g/g$, and $31.1{\mu}g/g$ after 72 h of fermentation in CFWG, showing 82.89% in DPPH radical scavenging activity, 106.32% in ABTS radical scavenging activity, and 1.47 ($OD_{593nm}$) in FRAP assay, respectively. From these results, we suggest that the high antioxidant activity of CFWG might be related to the markedly higher levels of total phenolic contents, isoflavone-malonylglycosides, -acetylglycosides, and -aglycones achieved during fermentation.

• Journal of Nutrition and Health
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• v.37 no.1
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• pp.45-51
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• 2004

In this study, isoflavone (genistein, genistin, daidzein, daidzin) contents in various parts of twelve soybean cultivars and three soy sprouts were determined by high performance liquid chromatography with UV detector. Three cultivars of soybean were selected and cultured in the lab to produce sprout for five days. Total isoflavone (Total IF) varied greatly among differnt breeds of soybean in range of 99 - 649.9 $\mu\textrm{g}$/g and 522.3 - 1,277.7 $\mu\textrm{g}$/g respectively, domestic and foreign cultivars. There were greatly difference in total IF of various parts of the soybean sprouts. Sprout from the Myunjunamul-kong appeared to have 69% genistein and 22% genistin in head part, and 30% and 62% of daidzin and daidzein, respectively, in root. Meanwhile, the sprouts from Junjori contains most (84%) of daidzein in its root. Sprout from chinese black-soybean had the largest amount of genistein among the sprouts but, there were no differences in the average genistein content between three selected black and non-black soys. The glycosidic form of IF were dominant compared to aglycone forms both in soybean and sprouts by 24 times and 12 times, respectively, suggesting that during the sprouts cultivation glycosidic forms could change to aglycone forms. There are no difference in total content between genistein + genistin and daidzein + daidzin in soy and soy sprout. Therfore, considering the total IF contents, the intake of 1 soy sprout is similer to 1.5 times as soybean.

• Journal of Nutrition and Health
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• v.35 no.4
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• pp.409-413
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• 2002

The purpose of this study was to determine to which differences in the source of protein (soy vs casein) and of isoflavones in soy protein are responsible for differential effects of bone mineral density and bone mineral content. Thirty 21-d-old Sprague-Dawley young rats were divided into 3 groups: the control group was find a casein-based diet, the soy concentrate group was fed soy protein with totally reduced isoflavones content (isoflavone 0.07 mg/g protein), and soy isolate group was fed with a higher isoflavone content (isoflavone 3.4 mg/g protein) than normal. The animal was scanned to determine the BMD and BMC using dual energy X-ray absorptiometry (DEXA, Lunar Corporation, Madison, WI). The soy concentrate group had significantly higher total body calcium/weight and total mineral content/weight than the casein group. The soy isolate group had significantly greater total bone mineral density/weight, spine bone mineral density/weight, and femoral bone mineral density (in g/$\textrm{cm}^2$ than the control and soy concentrate group. The findings of this study suggest that soy protein and isoflavones in soy protein are beneficial for bone-formation in growing male rats. Therefore exposure to these soy protein and isoflavones early in life may have long-term health benefits for bone diseases such as osteoporosis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.25-45
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• 1996

Soyfoods have potential roles in the prevention and treatment of chronic diseases, most notably cancer, osteoporosis, and heart disease. There is evidence that carcinogenesis are supressed by isolated soybean derived products in vivo such as a protease inhibitor, phytic acid, saponins and isoflavones. It is believed that supplementation of human diets with soybean products markedly reduces human cancer mortality rates. Especially, recent papers recognize the potential benefit of soybean isoflavone components for reducing the risk of various cancers. Isoflavones exhibit a multitude of medicinal effects that influence cell growth and regulation, which may have potential value in the prevention and treatment of cancer. In addition to potential biological effects, soybean isoflavones have the important physiological functions such as the induction of Bradyrizobium japonicum nod genes and the responses of soybean tissues to infection by Phytophthora megasperma as well as biochemical activities such as antifungal and antibacterial actions. Genistin, daidzin, glycitin and their aglycone (genistein, daidzein, glycitein) are the principal isoflavones found in soybean. Malonyl and acetyl forms have also been detected but they are thermally unstable and are usually transformed during the processing in glucoside form. Most soy products, with the exception of soy sauce, alcohol-extracted soy protein concentrate, and soy protein isolate, have total isoflavone concentrations similar to those in the whole soybean. Soybean-containing diets inhibit mammary tumorigenesis in animal models of breast cancer, therefore, it is possible that dietary isoflavones are an important factor accounting for the lower incidence and mortality from breast cancer. Of the total soybean seed isoflavones, $80\~90\%$ were located in cotyledons, with the remainder in the hypocotyls. The hypocotyls had a higher concentrations of isoflavones on a weight basis compared with cotyledons. Isoflavone contents were influenced by genetics, crop years, and growth locations. The effect of crop year had a greater impact on the isoflavone contents than that of location. The climate condition might be the attribution factor to variation in isoflavone contents. Also, while the isoflavone content of cotyledons exhibited large variations in response to high temperature during seed development, hypocotyls showed high concentration in isoflavone content. So, it is concluded that one of the factors affecting isoflavone content in soybean seeds is temperature during seed development. High temperature, especially in maturity stage, causes lower isoflavone content in soybean seed. It is also suggested that there may exist a different mechanism to maintain isoflavone contents between cotyledon and seed hypocotyls. In a conclusion, soy foods may be able to have a significant beneficial impact on public health.

• Journal of Nutrition and Health
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• v.38 no.6
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• pp.411-418
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• 2005

To elucidate the effect of soy isoflavone supplementation and exercise on serum lipids in normolipidemic and mildly hyperlipidemic postmenopausal period, 54 women residing in Seoul area were recruited. The subjects were divided into 4 groups: control group (n=13), isoflavone group (n=14), exercise group (n=14), isoflavone + exercise group (n=13). The control group was given placebo capsules, isoflavone group was given soy isoflavone supplements (90 mg/day), exercise group was given placebo capsules and exercised 3 times/week, over 30 min/time, and isoflavone + exercise group took soy isoflavone supplement and exercised. The duration of study were 8 weeks. The average age of the subjects was 57.0 years, 56.0 years, 54.4 years, and 55.2 years, respectively. There were no significant differences among the four groups in terms of height, weight, and body mass index. There were no significant differences among the four groups in terms of serum, total cholesterol, HDL-cholesterol. But the subjects indicated a significant difference in serum LDL-cholesterol (110.5 mg/day in before versus 74.6 mg/day in after) in the isoflavone + exercise group at the levels of p<0.05. In conclusion, the isoflavone supplementation and exercise may be helpful to decrease serum lipids of normolipidemic and mildly hyperlipidemic postmenopausal women.