• Journal of Applied Biological Chemistry
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• 제48권2호
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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.

• Food Science and Biotechnology
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• 제15권1호
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• pp.102-106
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• 2006

The phytoestrogens including isoflavones (genistein, daidzein, biochanin A, formononetin, and glycitein), coumestrol, and lignans (secoisolariciresinol, matairesinol, and anhydrosecoisolariciresinol) were quantified in edible sea vegetables from Korea. Sea vegetable samples were collected based on domestic consumption data. After hydrolysis of phytoestrogen glycosides in prepared samples, aglycones of phytoestrogens were extracted with diethyl ether and analyzed with isotope dilution gas chromatography-mass spectrometry in selected ion monitoring mode (ID-GC-MS-SIM). Total samples included 19 samples representing eight species. Most of the samples showed rather low concentrations, ranging from not determinated to $79.2\;{\mu}g/kg$ for isoflavones and from 106.4 to $694.8\;{\mu}g/kg$ for lignans. The daily intake of phytoestrogen from sea vegetables, estimated from the present data and domestic consumption data, was about $0.13\;{\mu}g/day$ for isoflavones and $2.0\;{\mu}g/day$ for lignans. When we compared these results with those from legumes, sea vegetables would not be considered the major source of phytoestrogens in the Korean diet.

• Archives of Pharmacal Research
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• 제23권5호
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• pp.461-466
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• 2000

Tectorigenin and kaikasaponin III from the flowers of Pueraria thunbergiana showed potent hypoglycemic and hypolipidemic effects in the streptozotocin-induced diabetic rats. Intraperitoneal administration of these two compounds with 5 and 10 mg/kg, respectively, for seven days to streptozotocin-induced rats significantly reduced the blood glucose, total cholesterol, LDL- and VLDI-cholesterol and triglyceride levels when compared with those of control group. Glycitein in which 5-OH is unlinked and tectoridin (7-O-glycoside of tectorigenin) isolated from the flowers of P. thunbergiana did not improve hyperglycemia and hyperlipidemia. In addition, tectorigenin showed in vitro antioxidant effects on 1,1-diphenyl-B-pirylhydrazyl (DPPH) radical, xanthine-xanthine oxidase superoxide anion radical, and lipid peroxidation in rat microsomes induced by enzymatic and non-enzymatic methods. We further found that tectorigenin and kaikasaponin III protected the Vero cell line(normal monkey kidney) from injury by hydrogen peroxide. From these findings, it seems likely that the antioxidant action of tectorigenin and kaikasaponin III may alleviate the streptozotocin-induced toxicity and contribute to hypoglycemic and hypolipidemic effects.

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1147-1150
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• 2011

Xanthomonas oryzae causes rice bacterial blight, which has been reported as one of the most destructive diseases of rice. Metabolites were identified through cheonggukjang, a traditional Korean fermented soybean product fermented by the Bacillus spp., to control the bacteria. HPLC, MS, and UPLC-Q-TOF-MS analyses were performed to identify metabolites responsible for antimicrobial activity. In this analysis, the m/z values of 253.0498, 283.0600, 269.0455, 992.6287, and 1,006.6436 were identified as daidzein, glycitein, genistein, surfactin B, and surfactin A, respectively. The levels of surfactin B and surfactin A were found to be high at 24 h (4.35 ${\mu}g$/ml) and 36 h (3.43 ${\mu}g$/ml) of fermentation, respectively.

• Journal of Nutrition and Health
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• 제36권1호
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• pp.32-39
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• 2003

Phytoestrogens, especially soy-derived isoflavones, are receiving great scrutiny as a food supplement for preventing hormone dependent disease such as postmenopausal osteoporosis. Their beneficial effects are derived from aglycone form of isoflavones, such as daidzein, genistein or glycitein. In contrast to the common usage of soybean, black bean (Rhynchosia Molubilis : Yak-kong) has been used as a supplement for preventing postmenopausal osteoporosis in oriental medicine. To investigate the effects of the saliva, artificial stomach fluid, and digestive enzymes on the conversion of glycosidic isoflavone to aglycone form, soybean and black bean were extracted with 70% methanol and freeze-dried. The recovery yield of methanol extracts of black bean was 14.1% which was higher than that of soybean, 13.5%. In terms of total isoflavones, we routinely obtained larger amount of isoflavones from black bean than those from soybean. By incubating methanol extracts of soybean and black bean with IN HCI for 180 min, the proportions of aglycones relative to the total isoflavone were significantly increased (32.4% and 52.4%, respectively). In vitro conversion, digestive enzymes ($\beta$-glucosidase and $\alpha$-glucosidase) may hydrolyze glycosidic bond of isoflavone more effectively than saliva or artificial stomach fluid did. It seems to say that the activity of $\beta$-glucosidase was higher than those of $\alpha$-glucosidase. The rate of conversion of glucoside form to aglycone form in black bean and soybean was low in physiological condition (pH) tested, although the enzymatic hydrolysis of glucoside was active. These results demonstrated that the composition of aglycone in food may be the important factors in terms of the bioavailability of isoflavones. (Korean J Nutrition 36(1): 32-39, 2003)

• Journal of the Korean Society of Food Culture
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• 제31권3호
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• pp.213-219
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• 2016

Analysis of nutritional compositions of soybean sprouts cultivated with bamboo ash was carried out. Bamboo ash was utilized as sprouting water of soybeans and adjusted to 0.2, 0.6, 1.0, 1.4, 2.0, 6.0 and 10.0 g/L. Stem length and contents of isoflavone (daidzin, glycitin, genestin, daidzein, glycitein, and genestein) and vitamin C in soybean sprouts cultivated with 0.2 g/L were higher than those in soybean sprouts cultivated with only water. Potassium, magnesium, and calcium of all cultivation methods were detected in higher contents than others. In particular, potassium showed a high absorption rate in the soybean sprouts. The major amino acid was asparagine (616.05~849.15 mg/100 g, soybean eq.), and contents of lysine, leucine, and ornithine in soybean sprouts cultivated at 0.2 g/L were higher than those of methods by only water and addition of 6-benzylaminopurine. According to the results, soybean sprouts cultivated with 0.2 g/L of bamboo ash were effective for increasing nutritional compositions.

• The Korean Journal of Food And Nutrition
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• 제32권6호
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• pp.598-610
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• 2019

The purpose of this study was to investigate the quality characteristics and antioxidant activity by collecting four times on six samples of Jeonbuk regional soybean pastes (Doenjang) traditionally prepared for this study. The water content of samples decreased according to progress of the aging period and the water content of the fourth sample collected was 42.40~59.64% (p<0.05). The salinity of the fourth Doenjang samples was 11.80~18.60%. The amino-type nitrogen content was 122.67~540.33 mg% immediately after the preparation of Doenjang in the Jeonbuk region and the content of the fourth collection samples increased from 251.49 to 982.36 mg% (p<0.05). The isoflavone glycosides decreased but daidzein, genistein and glycitein, which are aglycones, increased during aging periods. The total polyphenol content of the fourth collected samples was 11.99~19.27 mg GAE/g (p<0.05). The DPPH radical scavenging activity, ABTS radical scavenging activity and FARP of the fourth Doenjang samples were 51.88~81.21%, 84.14~90.32%, and 1.08~3.11 mg Trolox/g, respectively. As a result of quality analysis on Doenjang, the superiority of traditional Doenjang has been proven by the increase of amino nitrogen content and antioxidant activity according to the aging period. However, factor analysis on quality differences of regional Doenjang should be conducted to ensure standardization and quality improvement.

• Food Science of Animal Resources
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• 제27권3호
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• pp.329-336
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• 2007

This study was designed to find the optimum conditions for converting isoflavone glycoside to aglycone by ${\beta}-galactosidase$. Three different forms of the enzyme were tested and the optimum enzyme concentration, incubation temperature, pH, and incubation time were determined. Before treatment with enzyme, isoflavone contained 89.4% glycoside including daidzin, glycitin and genistin, and only 10.6% aglycone including daidzein, glycitein and genistein. Among the enzymes tested, the highest rate of isoflavone hydrolysis to aglycone, 35%, was observed when 3 unit/g Fungal Lactase (Amano Enzyme) was used. Higher incubation temperatures resulted in a higher rate of hydrolysis along with a greater loss of isoflavone mass. Therefore, body temperature $(37^{\circ}C)$ may be adequate for isoflavone conversion, with 44.9% hydrolysis and less than 10% loss of mass. As expected, a higher amount of aglycone was produced at pH 7 compared with other pH values. During 5hr of incubation, the conversion of glycoside to aglycone increased dramatically from 0 to 1hr, and plateaued thereafter. In addition, commercial soy-based milk was hydrolyzed more effectively with ${\beta}-galactosidase$ when incubated for 5hr. Based on the above results, the optimum conditions for isoflavone hydrolysis by ${\beta}-galactosidase$ were for 3 hr at $37^{\circ}C$, pH 7 with 3 unit/g Fungal Lactase (Amano Lactase), yielding an average total amount of aglycone ranging from 40 to 47%.

• Korean journal of food and cookery science
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• 제26권2호
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• pp.214-219
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• 2010

In this study, phytoestrogen for the industrial production of soybean probiotics by lactic acid bacteria (LAB) was studied in a soybean extract. Soybean was fermented with LAB, Lactobacillus plantarum KCTC 3108 and Bifidobacterum longum ATCC 15707. The change in the content of various isoflavones (aglycone and glucoside) and the $\beta$-glucosidase activity in soybean during fermentation were investigated and shown to be dependent on the starter organism. Soybean extract powder fermented with L. plantarum showed the highest $\beta$-glucosidase activity and the greatest increase in the aglycone content. After 48h of fermentation, the contents of daidzin, genistin and glycitin in L. plantarum decreased from a mean initial levels of $83.03{\pm}2.17$, $168.13{\pm}8.17$ and $20.02{\pm}1.07$, respectively, to mean levels of $5.34{\pm}3.24$, $3.79{\pm}0.57$ and $1.87{\pm}1.09\;mg$/100 g. Whereas, after 48h fermentation, the contents of daidzein, genistein and glycitein increased from a mean initial levels of $8.09{\pm}0.78$, $11.20{\pm}0.84$ and $4.71{\pm}0.46$, respectively, to mean levels of $85.76{\pm}0.84$, $175.87{\pm}2.21$ and $22.41{\pm}0.91\;mg$/100 g. Taken together, these results suggested an increase of aglycones and decrease of glucoside in isoflavones occurred during fermentation, which coincided with an increase of $\beta$-glucosidase activity in the fermented soybean extract powder.

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.959-968
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• 2014

The changes in the ${\beta}$-glucosidase activity, total phenolic contents, isoflavone contents, and antioxidant activities during the fermentation of cheonggukjang by Bacillus amyloliquefaciens MJ1-4 with and without garlic were investigated. The levels of total phenolic and isoflavone-malonylglycoside, -acetylglycoside, and -aglycone contents increased, whereas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric reducing/antioxidant power (FRAP) assay results increased, but isoflavone-glycoside levels decreased during cheonggukjang fermentation. The levels of total phenolic and total isoflavone contents and the antioxidant activities were higher in cheonggukjang fermented without garlic (CFWOG) than in cheonggukjang fermented with garlic (CFWG) after 24 h of fermentation, but they were lower in CFWOG than in CFWG after 72 h of fermentation. In particular, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 15.18 mg/g, $264.4{\mu}g/g$, $16.4{\mu}g/g$, and $31.1{\mu}g/g$ after 72 h of fermentation in CFWG, showing 82.89% in DPPH radical scavenging activity, 106.32% in ABTS radical scavenging activity, and 1.47 ($OD_{593nm}$) in FRAP assay, respectively. From these results, we suggest that the high antioxidant activity of CFWG might be related to the markedly higher levels of total phenolic contents, isoflavone-malonylglycosides, -acetylglycosides, and -aglycones achieved during fermentation.