• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.1
• /
• pp.64-71
• /
• 2011

Health beneficial properties of soybean [Glycine max (L.) Merr.] isoflavones are well known. The objectives of this study were to determine and compare the isoflavone composition and concentrations of soybean varieties grown in different cultivated regions of Vietnam (i.e., upland and lowland). Total and individual isoflavone composition and concentrations were determined by high-performance liquid chromatography (HPLC). Total isoflavone concentrations varied from 1153 to $6604{\mu}g\;g^{-1}$ and averaging $3354{\mu}g\;g^{-1}$ across environments and varieties. In the lowland region, the highest total isoflavones concentration was observed in M103 cultivar ($5653{\mu}g\;g^{-1}$) and the lowest in VX9-3 ($1153{\mu}g\;g^{-1}$), whereas in the upland region the highest and lowest concentrations were in M103 ($6604{\mu}g\;g^{-1}$) and DT93 ($1938{\mu}g\;g^{-1}$), respectively. Across varieties, average total isoflavones concentration was higher in the upland than lowland region (3728 vs. $2980{\mu}g\;g^{-1}$). The malonylglucosides and acetylglucosides concentrations in upland soybean varieties were higher than those from the lowland region. Despite the presence of Genotype (G) x Environment (E) interactions, varieties with consistently high (M103) and low (VX9-3, DT93) isoflavone concentrations across environments were identified. This is the first report of isoflavones in Vietnamese soybean varieties, revealing large variation in isoflavones concentration and profile among different varieties and cultivated regions. Results will be useful in selecting high-isoflavones soybean varieties for growth in tropical regions.

• Journal of the Korean Chemical Society
• /
• v.53 no.4
• /
• pp.427-431
• /
• 2009

The thermodynamical mechanism of the extraction of soybean isoflavones from soybean residuals using organic solvent method has been studied. On the basis of experiments, a simple model for determining the distribution coefficients in organic solvent extraction was employed to calculate the thermodynamical functions between $K,\;{\Delta}H^0,\;{\Delta}S^0\;and\;{\Delta}G^0$ in the soybean isoflavones extraction process. The results show that the soybean isoflavones extraction is an endothermic and an entropy-increasing process: the ${\Delta}G^0$ decreases when the temperature arises.

• Journal of Pharmaceutical Investigation
• /
• v.40 no.6
• /
• pp.347-351
• /
• 2010

Isoflavones have received much attention because of their health-related and clinical benefits such as estrogenic and anti-oxidative activities as well as triggering of natural killer cell activity. However, there are few publications reporting the pharmacokinetic profiles together with physicochemical properties of main isoflavones. Therefore, the pharmacokinetic parameters of main aglycones, daidzein, glycitein and genistein after oral administration of soybean extracts were investigated and the physicochemical properties of soybean extracts were characterized. It was observed that angle of repose was $46^{\circ}$ and tap density, bulk density and porosity were 10.12, 4.3 and $0.86\;g/cm^3$ and the mean $AUC_{last}$ of daidzein, glycitein and genistein was $11.376\;{\mu}g{\cdot}h/mL$, $3.045\;{\mu}g{\cdot}h/mL$ and $0.825\;{\mu}g{\cdot}h/mL$, respectively. Cell viability was 60% at a concentration of 10 mg/mL. Taken together, it was suggested that isoflavones were contained in the soybean products and had an antioxidant activity and this study would be the basis to control the quality of soybean products and study of the bioequivalence between soybean products in future.

• Journal of Nutrition and Health
• /
• v.36 no.1
• /
• pp.32-39
• /
• 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)

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

• KSBB Journal
• /
• v.19 no.6 s.89
• /
• pp.421-426
• /
• 2004

The extraction and separation of isoflavones from Korean soybean were peformed by various mechanical and chemical extraction methods. They included solvent extraction, stirring, supersonification and sub/supercritical water extraction. From the experimental results of the variation of solvent extraction by change in composition, the increase in extraction of a specific compound by stirring or supersonic energy, and the application of supercritical fluid with superior solvating power over solvents, the sonification was the most desirable extraction method in extracting aglycone isoflavones, daidzein and genistein from Korean soybean.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.522-526
• /
• 1997

Soy isoflavones could be recovered with adsorption resin column chromatography from soybean cooking water produced during soymilk or tofu manufacturing process. The main isoflavones in the soybean cooking water were genistin and daidzin, and their concentration was $0.083{\pm}0.019$ and $0.11{\pm}0.017\;mM$, respectively. Their aglycones were not detected. pH of soybean cooking water was critical in this chromatographic process and the recovery of isoflavones, both genistin and daidzin, was maximum at pH 4.0. Adsorption of genistin on the resin was stronger than that of daidzin. Elution rate and height/diameter ratio also affected the recovery yield. Under the optimal conditions, about 85% of genistin and 70% of daidzin could be isolated from soybean cooking water. Soy saponins were also recovered with isoflavones.

• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.745-750
• /
• 1998

Soybean isoflavones known as an anticarcinogenic factor were evaluated in some Korean soybean foods by high performance liquid chromatography. Unfermented soybean foods contained predominantly isoflavone ${\beta}-glycosides$ (genistin and daidzin), but in the fermented soybean foods isoflavones were present mainly as aglycones (genistein and daidzein). Average contents of isoflavones of tofu, soymilk and soy sprout were 1, 151, 676 and 424 mg/kg, respectively. Among the fermented soybean products, soybean paste (Chongkukjang) was highest in the isoflavone content (920 mg/kg) and the degree of hydrolysis of ${\beta}-glycosidic$ bonds was ranged from 30 to 100%. Doenjang, Chunjang and Kanjang contained lesser amounts of isoflavones and their contents were 627, 291 and 10 mg/kg, respectively. Korean traditional fermented foods, Chongkukjang and Doenjang could be regarded as the excellent sources of soy isoflavone aglycones.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.164-164
• /
• 2022

The soybean (Glycine max(L.) Merrill), an important food crop in the world, is popular because of its high quality protein and oil content. Soybeans as a food have long been known for their beneficial effects on health and are well-recognized globally. Isoflavones, significant soybean secondary metabolic products, may be crucial in avoiding some cancers and lowering the risk of cardiovascular disorders. This study investigates the correlation between plant growth regulator and the effect on the isoflavone levels in soybean leaves. The study was carried out in the green-house of the southern crop department in miryang. Soybeans(Seonpung) were cultivated in 1/2000 of the Wagner pot. Ethephon(500, 1000, 2000 ppm) and ABA(100, 200, 400 ppm) were used as plant growth regulators, and they were each treated on R2, R5, and R7 stage. After treatment, leaves were sampled three times at intervals of 5 days, and the content of 6 isoflavones and coumestrol was analyzed. Soybean isoflavones were analyzed using Ultra Performance Liquid Chromatography (Acquity UPLC H-Class system, Waters). The isoflavones content showed an overall highly in the R5 stage, and the level was similar to that of no treatment in the R2 and R7 stage. The difference between the growth regulators was found to be higher than that of ethephon when ABA was treated. The coumestrol content was confirmed to be high in the order of R7, R5, and R2 on the treatment time, and it was found that the content increased as the treatment time was delayed. In the treatment with the growth regulator, the coumestrol content tended to be higher when ethephon was treated than ABA.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.1
• /
• pp.48-52
• /
• 2006

Naturally occurring soybean isoflavones are known to be influenced by various genetic and environmental conditions. Growth, yield, and isoflavone content were determined in four different cultivars of soybean grown under drained paddy and upland fields. Most of growth characteristics and yield components of four different soybean cultivars harvested in drained paddy field were greater than those in upland field, regardless of cultivar. By means of high performance liquid chromatography, total daidzein and genistein contents of soybean in drained paddy field were increased up to 40 and 35%, respectively, compared with those in drained paddy field. Besides isoflavone contents, the growth and yield of soybean were significantly affected by cultivar and field conditions, indicating the necessity of genetic program for soybean cultivars appropriate to drained paddy field conditions. In conclusion, converting paddy field into upland may effectively improve soybean cropping system, especially in terms of isoflavone increment under paddy field conditions.