• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.231-236
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• 2007

The isoflavone distributions of soy samples treated with soaking, oven-drying, and almond additions were determined by high performance liquid chromatography (HPLC). Oven-drying was performed to increase the amount of ${\beta}-glucoside$ isoflavones, and almonds were added to convert the ${\beta}-glucosides$ into their corresponding aglycones. Oven-drying at $100^{\circ}C$ for 4 hr significantly increased ${\beta}-glucoside$ levels and decreased $malonyl-{\beta}-glucosides$, while almond additions of 2.5% and 5.0% (w/w) significantly increased aglycone contents (p<0.05) for samples with 12 hr of drying. The rate of increase for genistein from genistin was faster than that of daidzein from daidzin with almond additions. The ${\beta}-glucosidase$ activity in the 5.0% added almond soybean samples was significantly higher than in the samples without added almond (p<0.05). The aglycone content increased from 1.62% in the raw soybeans to 61.55% in the 2.5% added almond soybean samples for 12 hr of incubation. The information from this study could be used to increase the isoflavone aglycone contents of soybeans by using natural products such as almonds, without organic solvent additions or microorganism fermentation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.96-96
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• 2020

Soybean seeds are important sources of non-nutritive health promoting metabolites. The contents of these metabolites are affected by both genetic and environmental factors. In the present study, the contents of five common isoflavones including daidzin, genistin, glycitin, malonyldaidzin, and malonylgenistin were analyzed in 72 soybeans of different seed coat colors, diversity, and of different origins including China (22), Japan (9), USA (12), India (4), and Korea (25). The average total isoflavone content (TIC) was maximum in Indian soybeans (3302.36 ㎍/g) and minimum in Chinese landraces (1214.95 ㎍/g). The Korean landraces had higher average TIC (2148.05 ㎍/g) than the USA genetic materials (1580.23 ㎍/g) and Japanese landraces (1485.99 ㎍/g). The content of malonylgenistin was in the range of 54.31 - 2385.68 ㎍/g in the entire population, and was the most abundant isoflavone irrespective of origin although there was content variation among individual soybeans. Besides, glycitin was the least concentrated isoflavone, and its content ranged from 0.00 to 79.79 ㎍/g. With respect to seed coat color, green soybeans from all countries displayed the maximum malonylgenistin and TIC contents. Exceptions were those of Korean and Indian origins where black and yellowish-green soybeans presented the highest malonylgenistin and TIC contents, respectively. In multivariate analysis, 92.72% of the variance was explained by the first two principal components, and the soybeans were grouped in to three clusters based on isoflavone contents. Overall, our findings signify the importance of seed coat color and origin as discriminant parameters, and provide wide spectrum of routes for breeding soybean cultivars.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.527-534
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• 1996

enistein (G), and daidzein (D), the major isoflavones, were analyzed in 14 varieties of Korean soybean and various processed soybean products by using high performance liquid chromatography. Isoflavone contents (G+D) were greatly variable among varieties ranged from 308.2 $\mu\textrm{g}$/g to 1,134.2 $\mu\textrm{g}$/g and highest in Danyopkong and Jinpumkong. Among hypocotyl, cotyledon and hull of soybean the concentration of the isoflavone (G+D) in the hypocotyl was highest ranged from 2,971.7 $\mu\textrm{g}$/g to 5,704.9 $\mu\textrm{g}$/g. The distributions of genistein and daidzein were also different in hypocotyl, cotyledon and hull. Higher ratio of daidzein to genistein (D/G) was found in the hypocotyl (4-12) compared to cotyledon and hull (0.1-4). Isoflavone (G+D) contents of soymilks (Sinpaldal#2, Eunhakong) prepared at 16 hour hydration were decreased to 1.1-1.2 times compared with that at 8 hour hydration. Commercial soymilks contained much lower isoflavone (G+D) than laboratory soymilks. Soybean curd (Eunhakong) prepared with MgCl$_2$ showed higher isoflavone (G+D) contents than that with CaSO$_4$. But these values of two different soybean curds made at laboratory were similar to those of 3 commercial curds. The concentration of the isoflavones in soybean sprout separated with 3 parts revealed highest in the head and lowest in the stem. Compared with non-fermented soybean foods the fermented soybean produfts, Kochujang and soybean paste, Duen Jang, showed very low contents of isoflavone (G+D),2.8-3.0 $\mu\textrm{g}$/ｇ, 35.9-63.6 $\mu\textrm{g}$/ｇrespectively.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.158-163
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• 2007

The compositions of tofus made with Baktae and Huktae were compared to those made with other respective types of soybeans. The lipid and protein contents of Baktae were 20.8% and 39.7%, while those of Huktae were 15.8% and 41.1%, respectively. In both soybean types, linoleic acid(18:2), oleic acid(18:1), and palmitic acid(16:0) accounted for more than 80% of the total fatty acids. The tofu made from Baktae was whiter than the tofu made from Huktae, as exhibited by a higher Hunter's L-value. The lipid content of the Baktae tofu(4.41%) was higher than that of the Huktae tofu(3.26%). The amino acid compositions of the Huktae and Baktae tofus were similar, with glutamic acid and aspartic acid being the most abundant amino acids in both tofus. However, the content of the limiting amino acid, methionine, increased 2.5-fold in the tofus as compared to the soybeans, on a per gram protein basis. Isoflavones were lost during tofu making as contents for the tofu were 20${\sim}$25% of those for the soybeans.

• Journal of Mushroom
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• v.20 no.1
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• pp.7-12
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• 2022

The ascomycete fungus Cordyceps militaris infects lepidopteran insect pupae, forming characteristic fruiting bodies called "Dong Chung Ha Cho" in Korean. They have been used as medicines owing to their anti-allergic, anti-inflammatory, and immune-enhancing effects. This fungus can be grown on the geminated soybeans Rhynchosia nulubilis, which also contains several novel isoflavones. We performed a comparative transcriptome analysis to determine core gene sets or pathways contributing to biologically active products such as isoflavone. Initially, we sequenced 2-week-old fungal cultures on different soybean agar media, where different amounts of water agar were implemented to show different surface topology. We selected 830 upregulated and 188 downregulated genes by comparing linear models of the samples (two-fold change threshold). Gene ontology analysis identified that the "IMP biosynthesis" term was significantly found in the upregulated gene sets. The pathway is involved in the synthesis of cordycepin, the reference chemical for C. militaris. This finding in the transcriptome data is consistent with the previous observation: increased cordycepin concentrations in the C. militaris cultured on germinated soybean.

• Journal of Applied Biological Chemistry
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• v.51 no.6
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• pp.253-261
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• 2008

Isoflavone daidzein is a phytoestrogen widely distributed in Leguminosae and is especially rich in the soybean. The C6-C3 (rings B and C) unit of isoflavones is derived from the phenylpropanoid pathway and the remaining C6 (ring A) unit is from the polyketide pathway. This unique carbon skeleton is the result of isomerization of the flavone catalyzed by the isoflavone synthase, a cytochrome P450 enzyme. The isoflavones daidzein and genistein are present in the plant mostly in the glucosylated forms. However, in the human intestine, the glycosidic linkage is broken, and the free form is uptaked into blood stream. The free form is further metabolized into various reduction products to end up at the equol, which is known to have the most potent estrogenic effect among the metabolites. Several human intestinal bacteria that can convert daidzein into equol have been described, and the study into the chemistry and biochemistry of the daizein reduction would be rewarding to the improvement of the human health.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.165-176
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• 2010

Soybean seeds contain many biologically active secondary metabolites, such as proteins, saponins, isoflavones, phytic acids, trypsin inhibitors and phytosterols. Among them, saponins in soybeans have attracted considerable interest because of their health benefits. Soyasaponin A and B are the most abundant types of saponins found in soybeans along with soyasapogenol (aglycone), which is a precursor of soyasaponin. The main purpose of this experiment was to determine the concentration of soyasapogenol in soybean seeds and sprouts as a function of seed size, usage, seed coat color and seed cotyledon color. The 79 Korean soybean varieties were cultivated at Yesan of Chungnam in 2006 for the analysis of soyasapogenol using HPLC with Evaporative Light Scattering Detection (ELSD). The total average concentration of soyasapogenol was $1313.52{\mu}g\;g^{-1}$ in soybean seeds and $1377.22{\mu}g\;g^{-1}$ in soybean sprouts. Soybean sprouts were about 5% higher than soybean seeds in average total soyasapogenol concentration. In the process of sprouting, the average soyasapogenol A content decreased by approximately 1.6%, but soyasapogenol B and total soyasapogenol increased by 8.31% and 4.88%, based on the content of soybean seeds. When classified according to the size of seeds, the total soyasapogenol concentration of soybean seeds were not significantly different (p<0.05) On average, small soybean seeds were increased by as much as $103.14{\mu}g\;g^{-1}$ in sprouting process. As a function of the use of the seeds, The total soyasapogenol in soybean seeds were significantly different (p<0.05). While, the soybean sprouts were not significant different (p<0.05). Altogether, sprout soybean seeds show the greatest change in content during the germination process. When seeds with different coat colors were compared, the total soyasapogenol concentration of soybean with yellow seed coats ($1357.30\mu g\;g^{1}$) was slightly higher than that of soybean with black ($1260.30{\mu}g\;g^{-1}$) or brown ($1263.62{\mu}g\;g^{-1}$) seed coats. For the color of the cotyledon, the total soyasapogenol concentration was significantly increased in green cotyledon during the germination and seedling process. The results of this study suggest the functional characteristics of soybeans through quantitative analysis of soyasapogenol. In addition, the concentration of soyasapogenol exhibited a change during the germination process, which was evaluated by the nutritional value of the soybean sprouts.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.643-646
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• 2006

Cheonggukjang, a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in a temperature-controlled room by traditional methods in which steamed soy was exposed to rice straw naturally rich in Bacillus species. B. subtilus and B. licheniformis were found to be the major microorganisms present in cheonggukjang made by the traditional method. We analyzed the composition of 12 kinds of isoflavones and their glycosides present in cheonggukjang collected at various fermentation times. Total isoflavone content in raw soybeans was 2,867 mg/kg and this decreased by about 50% during cooking prior to cheonggukjang preparation. However, total isoflavone content changed slightly during 45 hr of fermentation. Total content of isoflavone glycosides, consisting mainly of daidzin, glycitein, and genistin, decreased by about 40% during 45 hr of fermenting cooked soybeans. The contents of tree isoflavones including daidzein, glycitein, and genistein showed a dramatic increase during fermentation in cheonggukjang preparation, with a 2.9-, 54.0-, and 20.6-fold increase in concentration, respectively, by the end of fermentation (45 hr). In conclusion, short-term fermentation of cooked soybeans with Bacillus species caused conspicuous changes in the composition of isoflavone derivatives, and its implication in terms of health benefits deserves further study.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1699-1708
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• 2021

Response surface methodology was applied to determine the optimum extract conditions(extract temperature and time) for the high-quality Agakong beverage. The optimal roasting condition for Agakong was set at 250 ℃ for 30 minutes. As quality criteria of Agakong, pH, color values and isofavone contents with extract temperature and extract time, the probability value (p<0.01) demonstrated a high significance for the regression model. It was found that the higher the extraction temperature and the longer the extraction time, the higher the isoflavones content. The optimized conditions of extraction isoflavones from agakong were found to be optimized ratio of extraction temperature 99.5℃, extraction time 1.7 h and the maximum rutin yield was 10.63 ㎍/mL.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.311-323
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• 2016

By studying bioactivity in the aspect of skin care via curcumin, the main component of turmeric, and isoflavones, the soybean extract, this research tried to prove the possibilities as cosmetic ingredients. This research identified the curcumin and soybean extract's anti-inflammatory and toxic effects on skin cells through cell experiment, and using HPLC, the moisture, oiliness, and changes in erythema were measured when the soybean extract was applied to the skin. The result showed that curcumin had the least toxin on RAW 264.7 cell and the anti-inflammatory effect was identified. There were statistically significant changes on the moisture, oiliness and erythema when cosmetics containing curcumin and soybean extract were used. Therefore, it showed the possibilities of the utilization of curcumin and soybean extract to be used as cosmetics for acne skin.