• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.25-45
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• 1996

Soyfoods have potential roles in the prevention and treatment of chronic diseases, most notably cancer, osteoporosis, and heart disease. There is evidence that carcinogenesis are supressed by isolated soybean derived products in vivo such as a protease inhibitor, phytic acid, saponins and isoflavones. It is believed that supplementation of human diets with soybean products markedly reduces human cancer mortality rates. Especially, recent papers recognize the potential benefit of soybean isoflavone components for reducing the risk of various cancers. Isoflavones exhibit a multitude of medicinal effects that influence cell growth and regulation, which may have potential value in the prevention and treatment of cancer. In addition to potential biological effects, soybean isoflavones have the important physiological functions such as the induction of Bradyrizobium japonicum nod genes and the responses of soybean tissues to infection by Phytophthora megasperma as well as biochemical activities such as antifungal and antibacterial actions. Genistin, daidzin, glycitin and their aglycone (genistein, daidzein, glycitein) are the principal isoflavones found in soybean. Malonyl and acetyl forms have also been detected but they are thermally unstable and are usually transformed during the processing in glucoside form. Most soy products, with the exception of soy sauce, alcohol-extracted soy protein concentrate, and soy protein isolate, have total isoflavone concentrations similar to those in the whole soybean. Soybean-containing diets inhibit mammary tumorigenesis in animal models of breast cancer, therefore, it is possible that dietary isoflavones are an important factor accounting for the lower incidence and mortality from breast cancer. Of the total soybean seed isoflavones, $80\~90\%$ were located in cotyledons, with the remainder in the hypocotyls. The hypocotyls had a higher concentrations of isoflavones on a weight basis compared with cotyledons. Isoflavone contents were influenced by genetics, crop years, and growth locations. The effect of crop year had a greater impact on the isoflavone contents than that of location. The climate condition might be the attribution factor to variation in isoflavone contents. Also, while the isoflavone content of cotyledons exhibited large variations in response to high temperature during seed development, hypocotyls showed high concentration in isoflavone content. So, it is concluded that one of the factors affecting isoflavone content in soybean seeds is temperature during seed development. High temperature, especially in maturity stage, causes lower isoflavone content in soybean seed. It is also suggested that there may exist a different mechanism to maintain isoflavone contents between cotyledon and seed hypocotyls. In a conclusion, soy foods may be able to have a significant beneficial impact on public health.

• Food Engineering Progress
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• v.15 no.4
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• pp.355-361
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• 2011

The separation conditions for the enhancement of isoflavone contents in soybean by soaking and germination were developed, and the fermentation conditions of Chungkukjang were optimized by using response surface methodology analysis. The high-yield of isoflavone production was obtained when the conditions of soaking and gemination were at 25.6$^{\circ}C$, 7 hr and 29.1$^{\circ}C$, 42.4 hr, respectively. Total isoflavone contents in soybean (Daepung) by treatment were increased from 1,012 ppm to 1,912 ppm. Also, the optimum fermentation conditions of Chungkukjang were determined 39.96$^{\circ}C$, 1.32% (inoulum size) and 42.4 hr, respectively. Isoflavone contents in Chungkugjang under the optimum fermentation conditions were 1.3 times higher than the control (1,960 ppm).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.34-41
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• 2008

This study was conducted to investigate antioxidant component content during maturity for judgement of optimum harvest time in black soybean. For high-functional black soybean production, accumulation pattern of isoflavone and saponin contents and anti oxidative activity according to maturity stage were investigated. Varieties used in this experiment were Ilpumgemojeongkong and heukcheongkong, which are the recommended black soybean in Korea. Isoflavone and saponin contents during maturity period in black soybean was the highest at $6{\sim}7$ days earlier than general harvesting time. It was indicated that optimum harvesting time for high quality soybean were $3{\sim}7$ days earlier than harvesting time for higher yield. As a result of investigation about accumulation pattern of antioxidant components by maturity stages in seed, total isoflavone content was the highest at 61 DAF in Ilpumgeomjeongkong and at 77 DAF in Heukcheongkong. Contents of total saponin were the highest at 61 DAF and at 71 DAF, respectively. In case of leaf, total isoflavone content was the highest at 55 DAF in Ilpumgeomjeongkong and Heukcheongkong. Contents of total saponin were the highest at 18 DAF and at $55{\sim}71$ DAF, respectively. It showed that black soybean's leaf could be developed as a new health food material, owing to high contents of antioxidant components and biological activity and it's suitable harvest time was at $R_7$.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.149-155
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• 2003

Metabolic engineering for production of isoflavones in nonlegume plants could distribute the health benefits of these phytoestrogens in more widely-consumed grains. Series of investigation to check the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway have been conducted. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and nonlegumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the anthocyanin pathway was effective in conferring the ability to produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in nonlegume dicot and monocot tissues.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.77-84
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• 2003

Metabolic engineering for production of isoflavones in non-legume plants could distribute the health benefits of these phytoe-strogens in more widely-consumed grains. We investigate the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and non-legumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the antho-cyanin pathway was effective in conferring the ability produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in non-legume dicot and monocot tissues.

• 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.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.

• 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.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2007.11a
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• pp.27-31
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• 2007

This study relates to low and medium molecular weight isoflavone-${\beta}$-D-glucan produced by submerged liquid culture of Agaricus blazei, a method of producing the isoflavone-B-D-glucan using autolysis enzyme of Agaricus blazei mycelia, and use of the isoflavone-B-D-glucan for anti-cancer and immunoenhancing effect. In acordance with one aspect of the present study, it deals with a method of producing isoflavone-${\beta}$-D-glucan, which comprises the followings; 1) culturing and separating mushroom mycelia, 2) producing low-medium molecular weight isoflavone-${\beta}$-D-glucan from high molecular weight one. The cytotoxicity on human cnacer cell line (Caco-2, MCF-7), the expression of Cyclin D, Bcl-2, Bax protein, p21 protein, p53 protein in MCF-7 cells assessed by SDS-PAGE and immunoblotting, and other immuno related factors such as TNF-${\alpha}$ and IL-1B activities were examined. Structural identification of isoflavone-${\beta}$-D-glucan which showed cytotoxicity against cancer cell and immunoenhancing effects was carried by separation with DEAE-cellulose column chromatography, TLC, HPLC, IR, NMR. Clinical test for the cancer patients (n=119) for 6 month was carried out, and immunoenhancing factors (NK. cell number, ratio of T4/T8) were checked. We concluded the identified isoflavone-${\beta}$-D-glucan has immuno enhancing effects and could be useful for cancer chemoprevention.

• Food preservation and processing industry
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• v.6 no.2
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• pp.11-13
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• 2007

This study relates to low and medium molecular weight isoflavone-${\beta}$-D-glucan produced by submerged liquid culture of Agaricus blazei, a method of producing the isoflavone-B-D-glucan using autolysis enzyme of Agaricus blazei mycelia, and use of the isoflavone-B-D-glucan for anti-cancer and immunoenhancing effect. In acordance with one aspect of the present study, it deals with a method of producing isoflavone-${\beta}$-D-glucan, which comprises the followings; 1) culturing and separating mushroom mycelia, 2) producing low-medium molecular weight isoflavone-${\beta}$-D-glucan from high molecular weight one. The cytotoxicity on human cnacer cell line (Caco-2, MCF-7), the expression of Cyclin D, Bcl-2, Bax protein, p21 protein, p53 protein in MCF-7 cells assessed by SDS-PAGE and immunoblotting, and other immuno related factor such as TNF-a and IL-1B activities were examined. Structural identification of isoflavone-${\beta}$-D-glucan which shoed cytotoxicity against cancer cell and immunoenhancing effects was carried by separation with DEAE-cellulose column chromatography, TLC, HPLC, IR, NMR, Clinical test for the cancer patients (n=119) for 6 month was carried out, and immunoenhancing factors(NK cell number, ratio of T4/T8) were checked. We concluded the identified isoflavone-${\beta}$-D-glucan has immuno enhancing effects and could be useful for cancer chemoprevention.