• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.55-62
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• 2008

To obtain food materials of high isoflavone content from soy-sprouts, 8 soy-sprout varieties, Aga 1, Aga 2, Aga 3, Aga 4, Pungsannamulkong, Eunhakong, Jangkikong and Bosugkong, were grown into soy-sprouts for 7 days under light condition and stored for 5 days at 6 different temperatures; 3, 6, 9, 20, 30, and $40^{\circ}C$ in the dark. The isoflavone content of 7 days grown sprout varieties were highest in the order of Aga 3>Aga 1>Aga 2>Aga 4>Jangkikong>Bosugkong>Eunhakong>Pungsannamulkong. The highest isoflavone content of Aga 3 was $4,619{\mu}g/g$. The isoflavone content of soy-sprouts showed much varietal differences depending on the storage temperatures. Comparative high isoflavone content was obtained at storage temperatures of $6^{\circ}C$ and $20^{\circ}C$ while most of varieties showed low isoflavone content at $9^{\circ}C$ and $30^{\circ}C$. No constant trend in isoflavone content for the tested varieties along with the days to storage but most of varieties showed the highest isoflavone content in 3 days of storage. On the contrary, Aga 4 and Jangkikong showed high isoflavone content even at 5 days of storage. The comparatively high isoflavone content for 4 varieties including of Aga 3 out of 8 varieties was obtained from the treatment of one day storage at $20^{\circ}C$. Out of all treatments, the highest isoflavone content was obtained from one day storage at $20^{\circ}C$ for Aga 3 and the content was as high as $11,705{\mu}g/g$. In this experiment, soy-sprouts were believed to be made continuous growth during the storage because the sprouts were being dipped in water during the temperature treatment to protect soy-sprouts from drying. Thus, it is inferred that additional researches should be made to establish better method to increase isoflavone content in soy-sprouts during the storage.

• 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.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.568-575
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• 2003

Selection of high-quality varieties of sprout bean and bean sprout containing high levels of total isoflavones was performed by high performance liquid chromatography. The range and mean of total isoflavone contents of sixty six varieties of sprout beans were $247{\sim}2,256$ and $1209{\pm}470\;mg/kg$, respectively, with KLG10618, KLG11118, KLG10600, KLG10022, KLG1085 and sohokong containing the highest amounts of isoflavone among the samples. Medium-sized bean variety with green seed-coat color contained highest amount of total isoflavones among samples. The range and mean of total isoflavone contents of thirty varieties of bean sprouts were $768{\sim}3,343$ and $1,898{\pm}577\;mg/kg$, respectively, with soho bean sprout containing the highest total isoflavone content (3,343 mg/kg, dry basis). Total isoflavone contents of bean sprouts increased gradually during cultivation period, reaching maximum level on the 5th day of cultivation, and were the highest in the order of roots, cotyledon, and hypocotyl.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.57-62
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• 2008

Isoflavone content in various parts of six soybean cultivars and soybean sprout during germination was analyzed by high performance liquid chromatography. The parts analyzed were seed coat, cotyledon, and axis for seeds and whole sprout, root, hypocotyl, and cotyledon for sprout. Two cultivars, Aga3 which is known to have the smallest seed size and the highest isoflavone content among the Korean soybean cultivars and Pungsannamulkong which is the most widely being used as soy-sprout, were selected for sampling from 1 to 10 days after germination. At the same weight, the order of isoflavone content increased from seed coat to cotyledon to axis. The highest total isoflavone(isoflavone$\times$dry weight) content was observed in the cotyledon and the lowest in the seed coat. The cotyledon of the Aga3 variety had the highest total isoflavone content and the lowest was measured in the Pungsannamulkong variety. The highest total isoflavone content, $10,788{\mu}g/g$, was observed in whole sprouts(cotyledon+hypocotyl+root) on day 7 for Aga3. After day 7, there was a decreasing trend in isoflavone content as the germination period increased. Total isoflavone content in the cotyledon of Aga3 significantly increased after seed germination, whereas the isoflavone content in the cotyledon of Pungsannamulkong decreased. However, total isoflavone content in the root of both varieties increased while isoflavone content in the hypocotyls decreased after seed germination.

• Nutritional Sciences
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• v.9 no.3
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• pp.179-189
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• 2006

Objective: We investigated the efficacy of a 12-week supplementation of soy isoflavone with L-carnitine on the development of obesity in high fat-induced obese C57BL/6J mice, which are known as a good model of diet-induced obesity. Methods: We measured body weights, adipose tissue mass, serum/liver lipid profiles and fat cell size/number in C57BL/6J mice fed diets containing either low fat (4%) or high fat (35%), or high fat supplemented with soy isoflavone powder containing 10% isoflavone and L-camitine for 12 weeks. Results: Body weight gain, abdominal adipose tissue and liver weight were lower by 31% 78% and 31.4% respectively, in mice on high fat diet containing soy isoflavone+L-carnitine (SC mixture) compared with high fat diet group. Also, SC mixture improved serum lipid profiles such as total cholesterol (TC), triglycerides (TG), and liver lipid profiles such as total lipids and TG. As subsequent results, this SC mixture prevented high-fat diet from accumulating TG in the liver. The size of fat cell was also significantly decreased in SC mixture fed mice. At the end point of this experiment, our results showed that feeding with soy isoflavone for 12 weeks finally increased camitine palmitoyltransferase 1 (CPT 1) activity through elevating the level of CPT1 expression. Conclusions: This study suggests that long-tenn supplementation with dietary soy isoflavone and L-carnitine is more synergistically beneficial for the suppression of high-fat diet induced obesity by inhibiting liver TG accumulation and the gain in abdominal adipose tissue weight than that with soy isoflavone. The antiobesity effects of SC mixture might be attributed, at least in part, to the induction of fatty acid catabolism by soy isoflavone, genistein.

• 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.

• Korean Journal of Community Nutrition
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• v.9 no.5
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• pp.606-614
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• 2004

This study was conducted to investigate the attitude to various soy foods and to estimate dietary isoflavone intake among Korean adolescents. The survey was carried out by self-administered questionnaire with 800 middle and high school students residing in urban and rural areas and 714 questionnaires were collected: resulting in 89% response rate. The dietary isoflavone intake was estimated by food frequency questionnaire developed for rapid assessment of isoflavone intake. Soybean paste, soybean curd, soy milk, bean sprouts and dambuk were recognized as nutritious and healthy food in order. Dambuk got the lowest score in taste and flavor. Bean sprouts, soybean curd and soybean paste were recognized as familiar food in order. Stuffed rice in fried soybean curd got the highest score and Miso soup got the lowest in preference. More than 50% of the subjects consumed soybean paste stew/soup and soybean curd over twice per week and 12.3% of the subjects consumed soybean over once a day. The estimated daily intake of isoflavones ranged from 0 to 227 mg, and the mean daily isoflavone intake of the subjects was 28.1 mg (16.3 mg genistein and 12.0 mg daidzein) whereas the median value of isoflavone intake was 19.7 mg. There was statistically significant relationship among Kyung Gi Do, Chung cheung Do and Seoul residents in their intake of isoflavone. The highest monthly income group consumed isoflavone more than the other groups. These results suggest that Korean adolescent perceived the soybean dishes as high quality foods but they didn't take much because of difficulty to cook or less chance to eat. Nutrition education program is needed to enhance consuming soy foods for prevention of chronic diseases related to dietary isoflavone intake. More detailed information on easy cook method of soy food is also needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.84-92
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• 2020

For humans, soybean and soybean products are the main dietary sources of isoflvones, which are polyphenolic compounds that represent one of the most common categories of phytoestrogens. The objective of this study was to determine isoflavone concentrations in soybean cultivars during germination when treated with some biotic substances. Three soybean cultivars were germinated in replicated trials in 2018/2019 and their individual and total isoflavone concentrations were determined using HPLC (High-Performance Liquid Chromatography). Significant differences were observed in total isoflavone content were observed among cultivars regardless of years and treatments. 'Daepung2-ho' and 'Uram' had significantly higher total isoflavones than 'Pungsannaul-kong'. Differences among treatments were also significant for total isoflavone content. In 2018, with chitosan treatment, total isoflavone concentration ranged from 551.15 to 7584.07 ㎍ g^-1, with an average of 2972.64 ㎍ g^-1 across cultivars. In 2019, there was no significant difference among treatments in total isoflavone content. Regarding individual isoflavone concentrations, the malonyl-glucoside groups accounted for over 85% of the total isoflavone content, which is indicated that these groups play an important role with regard to isoflavone components in soybean seeds. The individual proportions in the total concentrations of isoflavones varied according to germination period and seed tissues. Glucosides and malonyl-glucosides showed differences in concentrations among seed tissues, aglycones were further accumulated as germination period was progressed. This study suggests that biotic substances have an impact on seed isoflavone content during germination. However, cultivars with consistently high or low isoflavone concentrations across biotic substance treatments were identified desspite differences in germination period and seed tissues, demonstrating that the genetic factor plays the most important role in isoflavone accumulation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.102-109
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• 2008

This study was performed to obtain fundamental information on growth adaptability and isoflavone contents of soybean cultivars in highland area of Korea. For this study, we cultivated nineteen cultivars and investigated yield and isoflavone contents. In Jinbu-myeon located at altitude of 600 m, most of cultivars showed more than 2.5 t/ha seed yield except three cultivars, and the range of isoflavone contents among nineteen cultivars was 715 to $2,545\;{\mu}g/g$. Cultivars with both high seed yield and isoflavone contents were Manrikong, Sinpaldalkong2, Cheongjakong, and Cheongjakong2 in this area. In Daegwallyeong-myeon located at altitude of 800 m, the range of seed yield and isoflavone contents was 1.4 to 2.4 t/ha and 437 to $2,370\;{\mu}g/g$, respectively. Cultivars with both high seed yield and isoflavone contents were Ilpumgeomjeongkong and Dooyookong in this area. Cultivars selected on the basis of seed yield and isoflavone contents in 2004 and 2005 showed also similar results for yield and isoflavone contents at farmer's field in highland area in 2006. In conclusion, it could be expected to produce soybeans having both higher yield and better quality if the selected soybean cultivars are cultivated in highland area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.365-374
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• 2021

Soybean isoflavones are essential secondary metabolites synthesized through the phenylpropanoid pathway, and they play vital roles in human health. Isoflavone content is a complex quantitative trait controlled by multiple genes, and the genetic mechanisms underlying isoflavone biosynthesis remain largely unknown. Therefore, the present study analyzed the content of isoflavone and expression of six key genes involved in its biosynthesis (i.e., CHS6, HID, IF7GT, IF7MaT, GmIMaT1, and GmIMaT3) during soybean seed germination. Isoflavone content was quantified using high-performance liquid chromatography, and isoflavone biosynthetic gene expression was analyzed using quantitative real-time PCR. Two cultivars, namely 'Daepung2ho' and 'Pungsannamulkong', which are high- and low-isoflavone cultivars, respectively, were used. Isoflavone accumulation gradually increased with the progression of the germination period. As such, malonyl glucosides accounted for over 80% of the total content, whereas acetyl glucosides were present at trace amounts. Transcriptional analysis of isoflavone biosynthetic genes demonstrated expression patterns parallel to isoflavone content; however, there was no clear correlation between isoflavone content and gene expression. Moreover, most isoflavone biosynthetic genes showed different expression patterns depending on the individual gene or genotypes. Among the tested genes, HID showed consistently higher expression, except at 3 days after germination, and its expression was upregulated in 'Daepung2ho' but downregulated in 'Pungsannamulkong'. In addition, all tested genes exhibited different expression patterns between cotyledons and hypocotyls and responded differently to the germination period. These findings suggest that the expression levels of isoflavone biosynthetic genes are not consistent with the germination period and appear to be genotype-dependent.