• Journal of Nutrition and Health
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• 제35권6호
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• pp.695-704
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• 2002

• Korean Journal of Food Science and Technology
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• 제36권4호
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• pp.558-562
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• 2004

Conditions for rapid quantification of isoflavones were studied. Rapid and clear separation of isoflavones (genistin and daidzin) was obtained using solvent system of chloroform : methanol : water : acetic acid (60 : 30 : 10 : 0.5, v/v/v/v). Quantification of each isoflavone separated by TLC was conducted by densitometry analysis. Genistin and daidzin were quantified in $0.15-1.80\;{\mu}g/{\mu}L$ range with 99% confidence. Concentrations of isoflavones in soybeans and kudzu roots originated from Korea were determined, and validity of TLC method for quantification of isoflavones was confirmed by comparison with HPLC analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제57권4호
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• pp.424-429
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• 2012

This study was carried out to investigate the influence of different planting time on the synthesis of isoflavone in black soybean, Three varieties used in this experiment were lpumgeomjeongkong, Cheongjakong and Heugcheongkong which had different ecotypes, repectively. Seeds were sown at different time, May 15th, May 30th and June 15th with planting density of $60{\times}15cm$. In order to analyze the content of isoflavone, we collected sample every 5 days from 30 days after flowering to harvest and analyzed them with UPLC. As sowing was delayed, the content of isoflavone increased in all of three varieties. The content of genistein was greater than daidzein and glycitein. Increase of Glycitein was not distinct from 55 days after flowering(DAF) and it was stable against temperature change during the seed developing period. Although the content of genistein in Ilpumgeomjeongkong from 50 to 55 DAF, in Cheongjakong from 40 to 55 DAF and in Heugcheongkong from 60 to 65 DAF was lower than the content of daidzein, it was higher than that of daidzein afterward. In the statistical analysis on the relationship between average temperature and the content of aglycone isoflavone at 5-day intervals from 30 DAF during the grain filling period, genistein in Ilpumgeomjeongkong showed meaningful correlation as y=-15.28x+407.9 ($R^2=0.505^*$), diadzein in Cheongjakong showed meaningful correlation as y=-6.188x-164.5($R^2=0.454^*$), and genistein showed significantly high correlation as y=-11.59x+297.6 ($R^2=0.545^{**}$). Taking all the above results into consideration, it was suggested that the regions suitable for high content of isoflavone in black soybean be the northern area of Gyeonggi-do and Gangwon-do, Chungcheongbuk-do and inland area of Gyeongsangbuk-do, where are relatively low average temperature from flowering stage($R_2$) during the grain filling period.

• Korean Journal of Breeding Science
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• 제50권4호
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• pp.442-452
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• 2018

In this study, we analyzed the growth characteristics and isoflavone content of 43 soybean varieties highly adaptable to highland areas. The flowering period of each cultivation zone was from July 15 to August 12 at Daewallyeong, from July 18 to August 11 at Jinbu, and from July 23 to August 13 at Gangneung. The accumulated temperature from flowering to maturity was $1,297^{\circ}C$ for Daegwallyeong, $1,391^{\circ}C$ for Jinbu, and $1,685^{\circ}C$ for Gangneung. Forty-three varieties were classified into four utilities; soy sauce and tofu, bean sprouts, cooking with rice, and vegetable and early maturity. The content of isoflavone was highest at $2,579{\mu}g/g$ in varieties for soy sauce and tofu usage. Five varieties ("Paldalkong," "Sinpaldal2," "Ilmikong," "Sinpaldalkong," and "Daepung") cultivated in Daegwallyeong had over $4,000{\mu}g/g$ of isoflavone. The isoflavone content of the region Daegwallyeong was different at the significance level of 0.1 (p=0.061) compared to Gangneung. There was no significant difference between Gangneung and Jinbu. It is thought that the low temperature of the maturation stage during the growing period affected isoflavone accumulation. The varieties with more than $3,000{\mu}g/g$ of isoflavone content in Daegwallyeong, Jindu, and Gangneung were "L29," "Williams82," "Ilmikong," and "Daepung." These were genetically and environmentally stable in isoflavone content. It is expected that this study will be used as basic data for the functional breeding and selection of soybean varieties highly adaptable to a specific region, and to help expand soybean cultivation areas in highlands.

• Korean Journal of Human Ecology
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• 제14권3호
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• pp.485-489
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• 2005

The purpose of this study is to investigate changes of isoflavone and nutrients during germination of soybean varieties and to determine the optimal germination condition for soybean processing. After 5 days' germination, water content of the soybeans increased in the order of Poongsannamoolkong> Sinpaldal#2> Black#1> Jinpumkong. Ash content was higher in the order of Poongsannamoolkong> Sinpaldal#2> Jinpumkong> black#1 soybean. All varieties of the soybean samples increased in ash content during germination. Crude fat content was higher in the order of Poongsannamoolkong> Black#1> Jinpumkong> Shinpaldalkong. Crude protein content was higher in the order of Shinpaldalkong> Black#1> Jinpumkong> Poongsannamoolkong. Polypeptide subunits separated from the SDS-PAGE of the entire proteins were showing comparatively high level in the range of 2-16KD in Jinpumkong and 2-21KD in Poongsannamoolkong till the first day of germination, 2-25KD in Sinpaldal#2 till the second day, and 6-27KD in Black#l till the third day. Changes of total isoflavone contents during germination showed different patterns in soybean varieties: Jinpumkong and Black#1 had the highest total isoflavone content on the fourth day of germination, Poongsannamoolkong and Sinpaldal#2 on the first and the second day of germination, respectively.

• Korean Journal of Food Science and Technology
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• 제34권1호
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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).

• Journal of the Korean Society of Food Science and Nutrition
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• 제37권3호
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• pp.302-308
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• 2008

This study was performed to evaluate the effects of soybean powder with rich aglycone isoflavone through bio-transformation on lipid metabolism and antioxidative activites in diet induced hyperlipidemic rats. The rats were randomly divided into four groups: NO (basal diet normal group), CO (high fat diet control group), BFF10 (soybean powder with rich aglycone isoflavone 10% group), and BFF20 (soybean powder with rich aglycone isoflavone 20% group). After 7 weeks of BFF10 or BFF20 diets consumption, the concentrations in serum triglyceride, total cholesterol, LDL-cholesterol, and atherogenic index ratios were significantly decreased in the BFF10 and BFF20 diets groups compared with those in the CO group. The activities of alanine amino transferase and aspartate amino transferase were significantly decreased in the BFF10 and BFF20 than those in the CO group. Thiobarbituric acid reactive substance levels of serum were decreased in BFF10 and BFF20 groups compared to that of the CO group. The super oxide dismutase activites were increased in BFF10 and BFF20 groups compared to that of the CO group.

• Microbiology and Biotechnology Letters
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• 제47권1호
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• pp.64-68
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• 2019

To utilize soybean leaf, which is a waste product in soybean production, as a value-added food material, this study aimed to investgate the extraction efficiency of isoflavone from soybean leaf and to characterize physicochemical properties of the extract. Maximum isoflavone content of $59.74{\pm}4.54mg/l$ was obtained from soybean leaf extracted at $90^{\circ}C$ for 12 h. DPPH (1,1-diphenyl-2-pricylhydrazyl) radical-scavenging activity and total polyphenol contents reached maximum levels of $67.26{\pm}3.64%$ and $1,688.68{\pm}97.37{\mu}g/ml$ chlorogenic acid equivalent, respectively. Based on the contents of isoflavone and total polyphenol, and DPPH radical-scavenging activity, optimum extraction conditions for soybean leaf using water as solvent were $90^{\circ}C$ and 12 h.

• Journal of Applied Biological Chemistry
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• 제63권4호
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• pp.305-317
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• 2020

This study investigated that change of the nutrients (including fatty acids, amino acids, and minerals) and total phenolic (TP), total flavonoid (TF), and isoflavone contents and antioxidant activities during the storage of soybean leaves containing high isoflavone contents at 5, 25, and 55 ℃ for 180 days. The contents of free amino acids were increased from 1313.81 mg/100 g at 0 day to 1776.15, 1693.93 and 1551.18 mg/100 g at 5, 25, and 55 ℃ storage for 180 days, respectively, but the values of fatty acids were little unchanged. The contents of minerals were detected from 51.65 mg/100 g (0 day) to 49.93 (5 ℃), 50.20 (25 ℃), and 61.21 (55 ℃) mg/100 g at 180 days, respectively. The levels of total isoflavones did not change during the storage periods. In case of storage at 55 ℃, the contents of glycosides (1347.78→2195.13 ㎍/g) and aglycones (342.79→480.61 ㎍/g) increased during storage, while the levels of malonylglycosides (2209.22→1289.48 ㎍/g) decreased. Also, the TP and TF contents were slightly increased from 9.31 and 8.61 mg/g at 0 day to 9.97 and 9.3 mg/g at 180 days, corresponding to the radical scavenging activities of 2,2-diphenyl-1-picrydrazyl, 2,4,6-azino-bis (3-ethylbenzthiazoline-6-sulphnoic acid), and hydroxyl increased from 30.91, 55.98 and 23.27% from 37.10, 62.54, and 30.95%, respectively.

• Journal of the Korean Applied Science and Technology
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• 제40권4호
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• pp.589-605
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• 2023

Soy isoflavones are attracting attention from postmenopausal women because of their beneficial effects on menopausal symptoms. This study was investigated whether a combination of soy isoflavone genistein and swimming exercise (Gen+SE) would have a beneficial synergistic effect on obesity and improvement of liver function compared to the genistein only (Gen) and swimming exercise only (SE) in ovariectomized mice. Ovariectomized mice were randomly divided into control group (Con), Gen, SE, and Gen+SE, and were fed a high-fat diet for 8 weeks. As a result of examining the body weight, weight of white adipose tissue, lipid accumulation of liver, and serum ALT and AST levels, both Gen and SE decreased compared to Con, and Gen+SE decreased more than compared to Gen and SE. The expression of inflammatory cytokines MCP-1, IL-6 and TNF-𝛼 genes in liver decreased in both Gen and SE compared to Con, and were further decreased in Gen+SE compared to Gen and SE. But The expression of adiponectin showed opposite results. The expression of fatty acid oxidation related genes in liver increased in both Gen and SE compared to Con, and were more effectively than increased in Gen+SE compared to Gen and SE. Therefore this study suggests that the interaction between soy isoflavone and swimming exercise is very effective controlling obesity and recovering decreased liver function, and this is caused by promoting fatty acid oxidation in the liver in ovariectomized mice.