• Journal of Nutrition and Health
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• v.35 no.6
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• pp.635-642
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• 2002

This study was performed to investigate the effects of isoflavone consumption on plasma and liver lipid profiles and immune responses in Sprague-Dawley male rats. Experimental animals fed isoflavone at various doses for 4 weeks (0, 1095, 2190, 4380 isoflavone mg/kg diet). Exposure to isoflavone decreased the food consumption and final body weights of rats without decreasing the relative weights of organs, hemoglobin and hematocrit. And the plasma cholesterol and LDL-cholesterol, liver total lipid, cholesterol and triglyceride concentrations were significantly decreased by isoflavone intakes. The absolute and relative weights of thymus were significantly decreased in groups fed isoflavone than in control. Also splenocyte proliferations with Con A or PHA were decreased according to isoflavone consumption in rats, although there was not significant. These results demonstrate that isoflavone intakes significantly improve lipid profiles in plasma and liver. But the effects of isoflavone intakes on immune responses are needed further experiments.

• 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 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.174-178
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• 2006

This study was conducted to compare the changes of isoflavone content grown at different planting dates and to determine a relationship between growing periods and isoflavone content, in soybean. A total fifty six soybean varieties, including summer type soybean, Chinese varieties and domestic soybean varieties, were used this experiment. Mean total isoflavone content of domestic soybean varieties was higher than summer type soybean varieties and Chinese varieties. And, the soybean isoflavone content was significantly increased in growth at late planting dates. Soybean isoflavone contents was increased with longer reproductive growth period. While, the relationship between seed weight and isoflavone content showed significantly negative correlation coefficient, -0.57 at Apr. 15, -0.51 at May 15, and -0.38 at Jun. 15, respectively planting dates.

• 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.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.426-431
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• 2003

This study was carried out to investigate the addition of water-soluble isoflavone into milk by means of microencapsulation technique. The yield of microencapsulation, sensory attributes, and capsule stability of water-soluble isoflavone microcapsules in milk were measured. Coating materials used was polyglycerol monostearate (PGMS), and core material was water-soluble isoflavone. The encapsulation yield of water-soluble isoflavone with PGMS was 67.2% when the ratio of coating material to core material was 15 : 1. The rate of water-soluble isoflavone release from capsules was 18, 19, and 25% when stored at 4,20, and $30^{\circ}C$ for 12 days in milk, respectively. In sensory evaluation, beany flavor and color of microencapsuled water-soluble isoflavone added milk were significantly different from uncapsuled water-soluble isoflavone added milk, however, bitterness was not significantly different. In vitro study, micro-capsules of water-soluble isoflavone in simulated gastric fluid with the range of 3 to 6 pHs were released 3.0∼15.0%, however, the capsules in simulated intestinal fluid with pH 7 were released 95.7% for 40 min incubation time. In conclusion, this study provided that PGMS as coating materials was suitable for the microencapsulation of water-soluble isoflavone, and the capsule containing milk was almost not affected with sensory attribute.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.134-146
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• 2022

BACKGROUND/OBJECTIVES: Accumulating evidence has shown the beneficial effects of isoflavone on health. There is limited information on the usual isoflavone intake for Koreans. This study examined the usual intake of total isoflavone and its major food sources in Koreans according to age and gender. SUBJECTS/METHODS: The dietary intake data of 21,271 participants aged 1 yrs and older from the Korea National Health and Nutrition Examination Survey (KNHANES) VII 2016-2018 were analyzed. The average isoflavone intake was estimated based on the 24-h dietary recall data in KNHANES and the isoflavone database from the Korea Rural Development Administration (RDA) and literatures. The usual isoflavone intake was estimated by applying the ratio of within- and between-participant variance estimated from the 2009 KNHANES data to the 7th KNHANES (2016-2018) data. The variance of the isoflavone intake was calculated using MIXTRAN macro with intake data for two days in the 2009 KNHANES. Complex sample analysis with stratified variables and integrated weights was conducted. RESULTS: The mean total isoflavone intake in the Korean population aged 1 yrs and older (n = 21,271) was 139.27 mg/d, which was higher than the usual intake of 47.44mg/d. Legumes were a major contributing food group (91%), with arrowroot being a major individual contributor to the isoflavone intake (67.2%), followed by 21.3% of soybean, 5.4% of bean sprouts, and 2.1% of tofu. The usual isoflavone intake was highest in the participants aged 50 to 64 yrs old and increased with age until 50 to 64 yrs and then decreased with further increases in age. The usual isoflavone intake of participants aged 65 yrs and older was higher for men than for women, showing gender differences. CONCLUSIONS: The usual dietary intake of isoflavone varied according to age and gender in the Korean population. This study showed that the usual isoflavone intake was lower than the average isoflavone intake. The difference between percentiles of the usual isoflavone intake was similarly smaller than the average intake. An estimation of average intake can be hindered by the occasional consumption of foods high in isoflavones, suggesting that the usual intake estimation method can be more appropriate. Further research will be needed to establish isoflavone dietary guidelines regarding the effects of isoflavone intake on health outcomes.

• Korean Journal of Community Nutrition
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• v.5 no.1
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• pp.120-129
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• 2000

Very little is known about the relation between isoflavone intake and menopausal symptoms in Korean woman To find the effects and correlations between these factors, questionnaires(maternal factors, menopausal symptoms) anthropometric measurement, 24hr dietary recalls, and urinary isoflavones analysis were conducted in 100 postmenopausal women residing in the Kyunggi-do rural area. The average age hight and weight of the subject were 61.5 years, 153.6 cm and 56.2kg. The average age at menarche, menopause, and menstrual cycle were 16.7 years, 47.2 years, 29.8 years, respectively. Most of the postmenopausal women experienced mildly menopausal symptoms. The mean calorie, protein and calcium intake were 1417.6 kcal(74.7% of the Korean RDA) 53.2 g(88.6% of the Korean RDA) and 454.0mg(65.6% of the Korean RDA) respectively. The ration of energy from carbohydrate, protein, and fat was 68: 15: 17 The average isoflavone intake from soy foods was 27.27 mg. The major food source of the isoflavone were soybeans and soybean curd. The average urinary isoflavone excretion was 2. 78nmol/mg Cr and showed significant positive correlation with isoflavone intake. Isoflavone intake from soy foods had a negative correlation with the severity of menopausal symptoms. Therefore, soy foods which contain isoflavone may have a protective effect on menopausal symptoms of women in Korea.

• Journal of Nutrition and Health
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• v.36 no.7
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• pp.667-674
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• 2003

The study was performed to investigate the effects of isoflavone and/or grape seed oil supplementation on serum and liver lipid profiles and bone strength in ovariectomized female rats. Female Spraque-Dawley rats were assigned into 4 groups of ovariectomized (O), isoflavone (0.085 mg/100 g b.w/day) in ovariectomized rats, grape seed oil in ovariectomized rats and isoflavone and/or grape seed oil in ovariectomized rats. After 8 weeks, biochemical profiles of serum, liver and bone were analyzed. Total food intakes, body weight gains and FER (food efficiency ratio) were not statistically significantly different among groups. Total cholesterol, triglyceride and LDL-cholesterol levels in serum were decreased by fed of isoflavone and/or grape seed oils. However, crude lipid and total cholesterol contents in liver were not affect of isoflavone and/or grape seed oil. The hepatic glutathione contents were increased by isoflavone and/or grape seed oil fed. The hepatic glutathione-S-transferase activity in isoflavone and/or grape seed oil supplemented groups were higher than that O group. Bone (scapular and femur bone) dry weight, femur of max weight and bending strength were no significant difference among groups. Our finding suggest that isoflavone/grape seed oils might have potential role for serum lipid profiles improvement and bone strength in vivo.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.206-211
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• 2007

This study estimated the isoflavone intake level in Koreans using Food Frequency Questionnaire and analyzed related variables. The results showed that the average daily intake of isoflavone in adults was shown as 23.1 mg. The isoflavone intake level at 50 percentile was 16.9 mg ($0{\sim}90\;mg$), and 10% of adults took almost 50 mg of isoflavone a day and 10% took about 5 mg a day. The major food sources for isoflavone in Koreans were in the order of soybean, soybean paste, soy milk, soybean curd (tofu), and bean sprouts; the intake was different depending on age, educational background, occupation, economic standard, and family type. The result showed higher isoflavone intake levels in the group over 30 years old and the highest isoflavone intake in subjects working in farming/fishery, followed by housemakers. According to the differences by families the families with elderly members showed 50% higher isoflavone intake than young families with friends or siblings. Depending on related ecological variables, therefore, various nutrition education programs should be developed for a variety of intakes of soybean foods, along with easy and simple cooking methods as parts of continuous research.