• Journal of Nutrition and Health
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• v.36 no.6
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• pp.549-558
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• 2003

The purpose of this study was to determine which differences in the source of protein (soy vs casein) and isoflavones in soy protein are responsible for the differential effects of bone marks and hormones in growing female rats. Forty-two 21-day-old Sprague-Dawley female rats were randomly assigned to one of three groups, consuming casein (control group), soy protein isolate (57 mg isoflavones/100 g diet), or soy protein concentrate (about 1.2 mg isoflavones/100 g diet). All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, estrogen and calcitonin were analyzed using radioimmunoassay kits. Diet did not affect weight gain and mean food intake. Food efficiency ratio was lower in the soy protein groups. The soy isolate group had a higher ALP and osteocalcin concentration and lower crosslinks value than the casein group. Therefore, the soy isolate groups had a higher bone formation/resorption ratio than the casein group. And, the soy group had significantly higher growth hormone than the casein group. The findings of this study suggest that soy protein and isoflavones are beneficial for bone formation in growing female rats. Therefore, exposure to these soy protein and isoflavones early in life may have benefits for osteoporosis prevention.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.380-386
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• 2005

Optimal conditions of ultrafiltration (UF) and nanofiltration (NF) were investigated for separation and concentration of isoflavones and oligosaccharides from Sunmul. Levels of COD, BOD, and suspended solids (SS) in UF and NF permeates were also determined to evaluate effectiveness of these processes for reducing water pollution. Optimal UF operation conditions to achieve minimal fouling and maximal flux were $33-34^{\circ}C$ operating temperature and 2.3-2.4 bar trans-membrane pressure. Recovery yields of isoflavones and oligosaccharides in UF retentate were 11.49-28.16% and 12.77-27.57%, respectively. Increase in volumetric concentration factor (VCF) resulted in more functional compounds of isoflavones and oligosaccharides passing through UF membrane. Total isoflavone and oligosaccharide yields decreased by 3% as VCF increased from 6.0 to 8.0 and from 8.0 to 10.0, while decreased significantly by 10% as VCF decreased from 4.0 to 6.0. Optimal NF operating conditions were 192-195 psig operating pressure at $30-33^{\circ}C$. Total yields of isoflavones and oligosaccharides significantly decreased at VCF 8.0, whereas did not decrease up to VCF 6.0 during NF operation. Therefore, VCF 6.0 was recommended for economical process. COD and BOD decreased by more than 98% after NF process, and SS were not detected after UF process. These results indicated sequential filtration process was useful for separation of isoflavones and oligosaccharides from Sunmul and for reducing water contaminants.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.481-485
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• 1992

Five isoflavones were isolated from the root of Caragana microphylla Lam. and the structures have been identified by means of chemical and physical methods. The isoflavones are 7-hydroxy-4'-methoxyisoflavone(formononetin), $form ononetin-7-O-{\beta}-glucoside(ononin)$, 7-hydroxy-3', 4'-methylenedioxyisoflavone(pseudobaptigenin), $7-O-{\beta}-glucuopyranosyloxy-3'- hydroxy-4'-methoxyisoflavone(calycosin-7-O-{\beta}-gluc-oside)$ and maackiain.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.539-547
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• 2015

This study investigated elementary school students' perception and recognition of soybean foods and assessed their intake levels of isoflavones. A survey was administered to 300 sixth grade students in Daegu. The amount of isoflavones consumed by students was estimated by food intake frequency and the 24-hour recall method based on their general dietary habits and perception of soybean foods. Subjects' mean height was 152.2 cm, mean weight was 45.2 kg, and body mass index was $19.4kg/m^2$. All subjects had knowledge of soybeans and most preferred bean-paste pot stew of all soybean-based foods. Students typically ingested isoflavones two or three times per week in the forms of tofu, bean-paste pot stew, and bean sprouts. The average amount of isoflavones consumed from soy foods was 26.43 mg/day (daidzein 9.27 mg/day and genistein 17.16 mg/day) as assessed by food frequency questionnaire and 30.83 mg/day (daidzein 13.63 mg/day and genistein 16.40 mg/day) by the 24-hour recall method, showing that the 24-hour recall method assessment amount was 4.4 mg higher than that of the food frequency questionnaire. The major food sources of isoflavones were soybean paste and soybeans. Those who were especially knowledgeable about soybean foods expressed the view that these sources were a good or affordable enriched source of isoflavones.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.365-369
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• 2002

Daidzein and genistein contents were determined for 46 varieties of soybean and several types of soyfoods using high pressure liquid chromatography. Average content of isoflavones in the soybeans was $809\;{\mu}g/g$ dry matter, ranging from 309 to $1610\;{\mu}g/g$, with Sinpaldal #2 and Dawon showing the highest and lowest amounts, respectively. Isoflavone contents of chonkukjang, soybean paste, and miso were 1045, 781, and $1067\;{\mu}g/g$, respectively. Isoflavone amounts in hard, semi-soft, soft, and fried tofus were 650, 895, 685, and $616\;{\mu}g/g$, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.139-144
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• 2001

To analyze their isoflavones contents by HPLC analysis during two years on 60 collected old local traditional soybean varieties from various districts of Korea was conducted. There was a yearly variation in the seed isoflavon concentrations. The total contents on 5 isoflavones were in the range from 16.21mg/g to 25.21 mg/g and from 6.47 mg/g to 15.44 mg/g, in 1997 and 1998, respectively. Collected soybean from Gunsnsi-1(25.21 mg/g) in 1997 and from Gangjingun-3 (16.50 mg/g) in 1998 showed the highest amount of isoflavones as compared with other collected soybean varieties. The highest amount among 5 isoflavones was genistin as 48.45% and 49.73%, in 1997 and 1998, respectively, indicating the genotypic variation in seed isoflavon contents of local soybean cultivar. Our data suggest that it may be feasible for improving soybean variety with higher antioxiadtive activity and substances.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7001-7010
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• 2014

Isoflavones are phytoestrogens and natural plant compounds which are similar to 17-${\beta}$-estradiol in chemical structure. It is known that they can act as estrogen agonists or antagonists, depending on endocrine estrogenic levels, but actions of isoflavones are rather complex due to large number of variables such as chemical structures and mechanisms. Some hypotheses on biological mechanisms have not satisfactorily been confirmed to date and human epidemiological and experimental studies have been relatively limited. Nevertheless, isoflavones and isoflavone rich foods have become a focus onf interest due to positive health benefits on many diseases, especially prevention of hormone-related cancers, cardiovascular disease, osteoporosis, and adverse postmenopausal symptoms, and improvement of physiological condition such as maintaining cognitive function. This review provides an overview of chemistry, analytical techniques (focused on human biospecimens), functions including biological mechanisms, and effects of isoflavones, on the basis of the available meta-analysis and review articles and some original articles, on health and cancer.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.736-742
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• 1999

Antioxidative and cytoprotective effects of tectorigenin and glycitein isolated from the pueraria thunbergiana and its derivative, genistein, were determined. Among these three compounds, tectorigenin and glycitein bearing 6-methoxyl groups in both isoflavones showed significant free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generating superoxide anion radical. Tectorigenin only showed a slight inhibitory effect on XOD. We further studied the inhibitory effects of these isoflavones on the lipid peroxidation in rat liver microsomes induced by enzymatic and non-enzymatic methods. Each of them exhibited inhibitory effect on both ascorbic $acid/Fe^{2+}-{\;}and{\;}ADP/NADPH/Fe^{+3}-induced$ lipid peroxidation. Moreover, tectorigenin exhibited the highest protection of hydrogen peroxide damage on HepG2 and Vero cells among the three isoflavones, in the cytoprotective assay. It was suggested that the pattern of antioxidative and cytoprotective effect of isoflavones could be crucially by the aromatic substitution of oxygen-containing groups.

• Journal of Applied Biological Chemistry
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• v.48 no.2
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• pp.49-57
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• 2005

Soy is an important food in Asia and many studies have suggested that the low incidences of chronic diseases in Asian countries are associated with diets that are rich in soy. Soy contains many kinds of phytochemicals, and soy isoflavones and soyasaponins have received considerable attention. Twelve isoflavone components have been isolated from soy: three aglycones (daidzein, genistein, and glycitein), and their respective nine glucosidic conjugates. Soy isoflavones are similar in structure to estrogen and exhibit both estrogenic and antiestrogenic activities. Soy isoflavones exhibit anticancer activity, can reduce the risk of cardiovascular disease, and are beneficial to brain and bone health. Soyasaponins are divided into three groups (A, B, and E saponins), and they exhibit hypocholesterolemic, anticancer, hepatoprotective, antioxidative, and anti-human-immunodeficiency-virus effects. Despite the abundant literature suggesting that soy isoflavones and soyasaponins have potential applications in preventive medicine, further research is needed to standardize dosages and ensure their efficacy.

• Nutritional Sciences
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• v.7 no.1
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• pp.17-22
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• 2004

This study was undertaken to determine the bioavailability of isoflavones in weanling Sprague-Dawley rats by providing diets containing different levels of soy isoflavones for 6 weeks: 0.025% (low isoflavone intake; LI), 0.125% (medium isoflavone intake; MI), and 0.25% (high isoflavone intake; HI). The subsequent fecal and urinary excretion of daidzein and genistein was then measured. As the levels of dietary isoflavones increased, the amount of food intakes significantly decreased, and weight gain was slower in female rats. In male rats, there was no significant difference in weight gains related to dietary intakes. Urinary excretion of daidzein and genistein was significantly higher in the MI and HI groups in both male and female rats than the control and LI groups. The recovery % of daidzein and genistein in the urine was significantly lower in the MI and HI groups. Fecal daidzein increased as dietary isoflavone intakes increased in female rats; however, in male rats the increase was significant only in the HI group. The recovery % of daidzein and genistein in the feces of female rats was not significantly different among the four groups. When dietary isoflavones were increased from 0.025% to 0.25%, the amounts of daidzein and genistein excreted in the urine and feces increased; however, the low recovery rate of both daidzein and genistein in the urine implies an increased bioavailability of isoflavones. We also observed sex-related differences in the urinary and fecal recovery of isoflavone intakes.