• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1043-1047
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• 2002

It is well known that soy isoflavones play beneficial roles in the prevention of chronic diseases such as breast cancer, cardiovascular disease and osteoporosis. However current data are not sufficient for estimating the level of isoflavone intake. To use the urinary isoflavone excretion as a maker of isoflavone intake,26 participants consumed the isoflavone extract capsule (90 mg soy isoplavones/capsule) daily for 3 months. The study compared effects of pre- and post-isoflavone supplement in the following parameters; physical examination, dietary recalls, and urinary isoflavon excretion. The average age, height and weight were 65.7 years, 149.4 cm, and 57.3 kg. Subjects maintained regular diet pattern, and average daily nutrient intakes between pre- and post- supplementation were not significantly different except vitamin A, carotene and vitamin C. There was no significant difference between pre- and post- supplementation in terms of daily isoflavone intake. The basal urinary isoflavone excretion was 8.37 mg/day (daidzein 6.23 mu genistein 2.14 mg), and average daily excretion rate was IS.8%. Urinary isoflavone excretion was significantly increased, after isoflavone supplementation for 3 months as compared the basal level (p<0.01). Our data suggest that urinary isoflavone level, especially daidzein and genistein, may be a useful maker to estimate isoflavone intake.

• 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.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.859-865
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• 2005

This study was designed to develop a microencapsulated, water-soluble isoflavone for application into milk and to examine the hypocholesterolemic effect of such a milk product in a rat diet. The coating material was medium-chain triglyceride (MCT) and the core material was watersoluble isoflavone. The microencapsulation efficiency was 70.2% when the ratio (w/w) of coating material to core material was 15:1. The isoflavone release from the microcapsules was 8% after 3-day storage at $4^{\circ}C$. In in vitro study, 4.0-9.3% of water-soluble isoflavone in simulated gastric fluid was released in the pH range of 2 to 5 after 60 min incubation; however, in simulated intestinal fluid at pH 8, 87.6% of isoflavone was released from the capsules after 40 min incubation time. In sensory analysis, the scores of bitterness, astringency, and off-taste in the encapsulated isoflavone-added milk were slightly, but not significantly, different from those in uncapsulated, isoflavone-added milk. In blood analysis, total cholesterol was significantly decreased in the isoflavone-added group compared with that in the control after 6-week feeding. Therefore, this study confirmed the acceptability of MCT as a coating material in the microencapsulation of water-soluble isoflavone for application into milk, although a slight adverse effect was found in terms of sensory attributes. In addition, blood total cholesterol was lowered in rats which had been fed a cholesterol-reduced and microencapsulated, isoflavoneadded milk for 6 weeks.

• 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.

• Proceedings of the KSCN Conference
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• 2004.05a
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• pp.439.1-439
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• 2004

콩단백질에 풍부한 isoflavones는 약한 estrogenic한 효과를 가진다고 보고 되면서 폐경 여성이나 난소절제쥐를 대상으로 골 대사에 미치는 효과에 대한 연구가 많이 이루어졌다. 그러나 isoflavones가 골대사에 미치는 효과는 isoflavones의 량, 섭취기간, 생리상태, 칼슘의 섭취량 등 여러 가지의 변수에 따라 다르게 나타났다. 일반적으로 isoflavones의 섭취가 너무 작거나 너무 많아도 그 효과 미미하여 isoflavones의 적당량에 대한 연구가 계속 요망되고 있다.(중략)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.423-428
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• 2004

Soybean seeds contain high amounts of isoflavones that display biological effects and isoflavone content of soybean seed can vary by year, environment, and genotype. Objective of this study was to identify quantitative trait loci that underlie isoflavone content in soybean seeds. The study involved 85 $F_2$ populations derived from Korean soybean cultivar 'Kwangkyo' and wild type soybean 'IT182305' for QTL analysis associated with isoflavone content. Isoflavone content of seeds was determined by HPLC. The genetic map of 33 linkage groups with 207 markers was constructed. The linkage map spanned 2,607.5 cM across all 33 linkage groups. The average linkage distance between pair of markers among all linkage groups was 12.6 cM in Kosambi map units. Isoflavone content in $F_2$ generations varied in a fashion that suggested a continuous, polygenic inheritance. Eleven markers (4 RAPD, 3 SSR, 4 AFLP) were significantly associated with isoflavone content. Only two markers, Satt419 and CTCGAG3 had F-tests that were significant at P<0.01 in $F_2$ generation for isoflavone content. Interval mapping using the $F_2$ data revealed only two putative QTLs for isoflavone content. The peak QTL region on linkage group 3, which was near OPAG03c, explained $14\%$ variation for isoflavone content. The peak QTL region on linkage group 5, which was located near OPN14 accounted for $35.3\%$ variation for isoflavone content. Using both Map-Maker-QTL $(LOD{\geq}2.0)$ and single-factor analysis $(P{\leq}0.05)$, one marker, CTCGAG3 in linkage group 3 was associated with QTLs for isoflavone content. This information would then be used in identification of QTLs for isoflavone content with precision

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.89-101
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• 2019

The variation of content of 12 soybean seed isoflavone components was determined in the aglycone, glucoside, malonylglucoside and acetylglucoside groups of 44 Korean soybean cultivars grown in 2016 as well as in 2017. The total isoflavone content of the 44 cultivars averaged at $2935.4{\mu}g/g$ and was in the range of 950.6 to $5226.3{\mu}g/g$ for two years. Malonylglucoside group averaged at $2437.2{\mu}g/g$ with the highest proportion of isoflavone composition (83.0%). Significant differences were observed between cultivars, years and their interactions for both the total isoflavone and each composition group contents (P < 0.0001); however, no year-wise differences were observed for daidzein and genistin. The broad-sense heritability ($h^2$) within the set of 44 Korean soybean cultivars was as high as 0.93 for the total isoflavone content and was in the range of 0.8-0.92 for each composition group of isoflavone except for acetylglucoside. The total isoflavone content in cultivar group for soy-sprout was higher ($3850.4{\mu}g/g$) than that for the other cultivar groups of soy-paste and tofu ($3082.8{\mu}g/g$), black or green soybean cooked with rice ($2345.8{\mu}g/g$), and early maturity group ($1298.6{\mu}g/g$). The total isoflavone content of 'Sowonkong', a soybean cultivar for soy-sprout, was the highest ($5226.3{\mu}g/g$). In the cultivar group for soy-paste and tofu, the average isoflavone contents of 'Daepung', 'Daepung2ho', 'Saegeum', 'Uram', and 'Jinpung' were higher than $4000{\mu}g/g$. With the exception of small seeded cultivars with low isoflavone contents such as 'Sohwang' and 'Socheongja', the seed size and total isoflavone content were significantly negatively correlated in 2016 and 2017, respectively ($r=-0.47^{**}$ and $-0.49^{**}$). The number of days of growth from flowering to maturity did not affect the variations observed in isoflavone content.

• Korean Journal of Community Nutrition
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• v.6 no.1
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• pp.69-75
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• 2001

Intake of soy protein the fisk factors associated with cardiovascular disease in postmenopausal women. This study was designed to effects of isoflavone supplementation on serum lipids in 16 hyperlipidemic postmenopausal women . For this purpose, an intervention study was conducted for 12 weeks. Subjects were healthy, free-living women consuming habitual diets with 0.3ｇ/ｄ of isoflavone. Food and nutrient intake was obtained by 24-hr recall method and anthropometric measurement were made. Systolic and diastolic blood pressure, total serum cholesterol. HDL-cholesterol and LDL-cholesterol were determined before and after the isoflavone supplementation. The results were summarized as follows. The average age, hight, weight and BMI of the subject were 65.3 years, 151.4 cm, 62.2 kg and 27.1, respectively. The systolic blood pressure and diastolic blood pressure were not reduced significantly with isoflavone supplementation. Total cholesterol (p＜0.001), HDL-C(p＜0.05), and LDL-C(p＜0.01) were significantly increased after isoflavone concentration. In conclusion, isoflavone supplementation was not effective to modify risk factors for cardiovascular disease.