Isoflavone Levels in Soy Foods Consumed by Multiethnic Populations in Singapore and Hawaii

University of California, Los Angeles, Los Ángeles, California, United States
Journal of Agricultural and Food Chemistry (Impact Factor: 2.91). 02/1999; 47(3). DOI: 10.1021/jf9808832


Concentrations and glucosidic conjugation patterns of isoflavones were determined in soy foods consumed by multiethnic populations in Singapore and Hawaii. Six raw and 11 cooked food groups traditionally consumed in Singapore and 8 food groups consumed in Hawaii were analyzed by reversed-phase high-pressure liquid chromatography with diode array detection. Mean total isoflavone levels varied between 35 and 7500 ppm, with the lowest values found in soy milk and burgers and the highest levels observed in soybean and its seeds and in supplements. Total isoflavone levels and conjugation patterns varied as a function of soybean variety, storage conditions, and food processing. A large contribution to the differences in total isoflavone content between food groups was due to the water content in foods and to leaching of polar analytes into the water phase during boiling. Soy protein drinks and traditional soy foods were found to possess very similar isoflavone amounts considering usual serving sizes. Keywords: Isoflavones; genistein; daidzein; glycitein; isoflavone conjugates; soy foods; supplements; high-pressure liquid chromatography; diode array detection

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    • "Information on the subjects' nutrient intakes was collected through a 3-day diet record that included 2 weekdays and 1 day on the weekend. Isoflavone consumption from foods was analyzed by CAN PRO 3.0 (The Korean Nutrition Society, Seoul, Korea) (Franke et al. 1999; Lee et al. 2000). "
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    ABSTRACT: We conducted a double-blind, randomized, placebo-controlled trial to evaluate the effects of soy-derived isoflavone on blood glucose, lipid profiles, and sex hormones related to cardiovascular disease in Korean postmenopausal women. One hundred thirteen postmenopausal women were recruited from the Seoul metropolitan area. To confirm postmenopausal and gynecologic status, the subjects were clinically examined by a gynecologist using ultra sound and X-ray. Finally, 85 postmenopausal women whose follicle-stimulating hormone (FSH) levels were higher than 40 IU/ml were enrolled. Subjects received either 70 mg isoflavone or placebo capsules daily for 12 weeks. As a result, the values of fasting glucose, insulin and HOMA-IR, as well as those of TC, LDL-C, HDL-C and FFA, were not different between the groups after supplementation. However, triglyceride (TG) levels in the treatment group decreased significantly compared with those of the placebo group (p = 0.0215). The levels of luteinizing hormone (LH) significantly decreased in the treatment group (p = 0.027); however, the levels of FSH, estrone and estradiol were not changed after intervention. In conclusion, isoflavone supplement of 70 mg/day for 12 weeks decreased blood levels of TG and LH in Korean postmenopausal women.
    Archives of Pharmacal Research 03/2013; 36(3). DOI:10.1007/s12272-013-0059-9 · 2.05 Impact Factor
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    • "The content and profile of isoflavones is generally determined by means of high-performance liquid chromatography (Prabhakaran et al. 2005). The concentration and distribution of each isoflavone derivative in soybeans depends on the soy origin (Franke et al. 1999; Genovese et al. 2006; Genovese and Lajolo 2002; Hutabarat et al. 2001), agricultural conditions, such as soy variety and crop (Wang and Murphy 1994a), and soy maturity (Lee et al. 2007; Wang et al. 2000). Generally, soybeans have significantly higher levels of daidzein and genistein and their corresponding glucosides (Fukutake et al. 1996; Rochfort and Panozzo 2007) and little content of the glycitein derivates (Wang and Murphy 1994a). "
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    ABSTRACT: Soy has been traditionally incorporated in diet as processed foods, such as soymilk, tofu, miso, tempeh, etc., and the consumption is commonly associated with a reduction of the development of chronic diseases due to their antioxidant, anti-inflammatory, and anti-allergic properties, among others. Many of the health benefits of soy have been attributed to isoflavones. They comprise a group of naturally occurring flavonoids consisting of heterocyclic phenols. Soy contains three types of isoflavones in four chemical forms: the aglycones daidzein, genistein, and glycitein; the β-glucosides daidzin, genistin, and glycitin; their 6″-O-malonyl-β-glucosides (6OMalGlc); and their 6″-O-acetyl-β-glucosides (6OAcGlc) conjugates. Industrial processing methods of soy-based food products commonly lead to the loss of isoflavones through removal of undesirable fractions. On the other hand, isoflavones can be transformed into different conjugates, which may have significant effects on the food texture and on the bioavailability and pharmacokinetics of the isoflavones. This article reviews the effect of a number of soybean processing treatments on the isoflavone content and profile. The preparation and manufacturing of different soy-based food and food ingredients, fermented and non-fermented, has been analyzed in terms of content and distribution of the three major isoflavone derivatives, daidzein, genistein, and glycitein, and their respective conjugates. KeywordsAglycone–Glucoside–Isoflavone–Daidzein–Genistein–Glycitein–Soy processing
    Food and Bioprocess Technology 01/2011; 4(1):27-38. DOI:10.1007/s11947-009-0311-y · 2.69 Impact Factor
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    • "Empowering the Food Professional cooked tofu was found to be 0.297 and 0.258 mg/g, respectively (Franke et al. 1999). Variation in isofl avone contents in tofu products was governed by the original content in soybeans and extent of loss in whey during recovery of soy curd. "
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    ABSTRACT: Tofu (instead of preparing using synthetic coagulant) was prepared using coagulants of plant origin (Citrus limonum, Garcinia indica, Tamarindus indica, Phyllanthus acidus and Passiflora edulis). Total crude protein and fat contents were highest in tofu prepared using G. indica and T. indica (72.5% dbw) compared to synthetic coagulant. Tofu prepared with natural coagulants had signifi cantly higher antioxidant activity compared to synthetic coagulant. Bioconversion of isoflavone glucosides (daidzin and genistin) into their corresponding bioactive aglycones (daidzein and genistein) was observed in tofu. The difference between glucosides and aglycones contents in soy milk was significant but there was not much difference in tofu coagulated with synthetic and natural coagulants.
    Journal of Food Science and Technology -Mysore- 08/2010; 47(4):387-93. DOI:10.1007/s13197-010-0064-7 · 2.20 Impact Factor
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