• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.641-645
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• 2005

Using aqueous solution of 60% ethanol, the isoflavones contained in the Soybean (Chungsun, Korea), Tawon (Suwon, Korea), Jackbean (Hongsung, Korea), Soybean (Jilin, China), Black Soybean (Jilin, China), Kidneybean (Jilin, China) and Soybean (California, U.S.A.) were extracted. In this work, the pretreatment step was composed of agitation extraction, filtration, concentration, ultracentrifuge, and membrane filtration. The analysis by $C_{18}$ column was performed, and the mobile phase applied was linearly changed with A/B of 85/15-65/35 vol% for 50 min (A water/acetic acid, 99.9/0.1 vol%, B acetonitrile/acetic acid, 99.9/0.1 vol%). Among the soybeans tested, the total amounts of the four isoflavones (daidzin, genistin, daidzein, and genistein) extracted by the soybeans from Korea, China and U.S.A. were 1.37, 1.60, and 2.25 mg/g, respectively. It was also found that the total amount of aglycone of daidzein and genistein from soybean (American California) was $144{\mu}g/g$, which was the largest for the soybeans experimented.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.89-101
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• 2019

The variation of content of 12 soybean seed isoflavone components was determined in the aglycone, glucoside, malonylglucoside and acetylglucoside groups of 44 Korean soybean cultivars grown in 2016 as well as in 2017. The total isoflavone content of the 44 cultivars averaged at $2935.4{\mu}g/g$ and was in the range of 950.6 to $5226.3{\mu}g/g$ for two years. Malonylglucoside group averaged at $2437.2{\mu}g/g$ with the highest proportion of isoflavone composition (83.0%). Significant differences were observed between cultivars, years and their interactions for both the total isoflavone and each composition group contents (P < 0.0001); however, no year-wise differences were observed for daidzein and genistin. The broad-sense heritability ($h^2$) within the set of 44 Korean soybean cultivars was as high as 0.93 for the total isoflavone content and was in the range of 0.8-0.92 for each composition group of isoflavone except for acetylglucoside. The total isoflavone content in cultivar group for soy-sprout was higher ($3850.4{\mu}g/g$) than that for the other cultivar groups of soy-paste and tofu ($3082.8{\mu}g/g$), black or green soybean cooked with rice ($2345.8{\mu}g/g$), and early maturity group ($1298.6{\mu}g/g$). The total isoflavone content of 'Sowonkong', a soybean cultivar for soy-sprout, was the highest ($5226.3{\mu}g/g$). In the cultivar group for soy-paste and tofu, the average isoflavone contents of 'Daepung', 'Daepung2ho', 'Saegeum', 'Uram', and 'Jinpung' were higher than $4000{\mu}g/g$. With the exception of small seeded cultivars with low isoflavone contents such as 'Sohwang' and 'Socheongja', the seed size and total isoflavone content were significantly negatively correlated in 2016 and 2017, respectively ($r=-0.47^{**}$ and $-0.49^{**}$). The number of days of growth from flowering to maturity did not affect the variations observed in isoflavone content.

• Food Engineering Progress
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• v.23 no.3
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• pp.209-216
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• 2019

The effects of fermentation on soy embryo have been investigated using lactic acid bacteria, Lactobacillus acidophilus (LA), Lactobacillus bulgaricus (LB), Streptococcus thermophilussei (ST), and Lactobacillus plantarum (LP). As a result of the fermentation test of the isoflavone conversion by strain type, inoculation content, and fermentation time, the optimum conditions were LP bacterium, an inoculum amount of 5%, and a fermentation time of 24 hours. The composition of the isoflavone glycosides in the control was the highest in the order of glycitin> daidzin> genistin. When fermented with lactic acid bacteria, glycoside content decreased, and aglycone content increased. The order of composition was daidzein>glycitein>genistein. In the fermentation with LP bacterium, soyasaponin Ab content decreased and Ba and Bb content increased. Upon assessing the result of the experiment, it was found that the pH of the fermentation broth had a great influence in the bioconversion of isoflavone and soyasaponin. In the case of fermentation by pH 6 broth, aglycone and Bb content was the highest. The increase of aglycone content by fermentation reaction with the LP bacterium can increase the physiological activity and functionalization of soy embryo, which is a byproduct of processing.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.101-101
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• 2020

Soybean is known as to have a several healthy ingredients. Among them, isoflavones are effective in reducing obesity, menopausal symptom. Isoflavones consist of 12 isomers, including Aglycon, Glucoside, Malonyl glucoside, Acetyl glucoside, and are usually found in soybean seeds. The content is determined by the sum of 12 isomers, and the content value difference between the varieties is huge. In this study, we investigated the agronomic traits, 12 isomer of isoflavone content and composition for 49 soybean germplasms. This germplasms were selected from the 23,000 germplasms with the highest total content of isoflavones possessed by the National Agrobiodiversity Center. Seed samples were cultivated in experimental field located in Jeonju City on April 04, 2019. Matured seeds were harvested and portions of each seed samples were oven-dried, pulverized, and analyzed for their isoflavone compositions using HPLC-DAD. The soybean samples showed distinction in their agronomic traits, isoflavone compositions and contents. The days to flowering ranged between 38 and 69 days while the days to maturity ranged between 103 and 156 days. The seed coat color of soybean germplasms was 24 in black, 10 in yellow, 2 in green, 5 in yellowish green, 4 in green with black spot, 4 in pale yellow. The germplasm with the highest total content of isoflavones was the IT178054(1257.61±7.98 ㎍/g), but the germplasms containing the largest number of isoflavone isomers were IT274592, IT275005, both germplasms had 11 isoflavone isomers excluding Malonyl glycitin. The largest source of Aglycon, the most easily absorbed isoflavone form in the human body, was IT274592(DZ: 8.83±0.30 ㎍/g, GL: 11.14±0.81 ㎍/g, GE: 8.16±0.26 ㎍/g), while only IT274592, IT275005, IT308619 contained all three components of Aglycon. In Principal Component Analysis(PCA), the first two principal components showed more than 3.5 Eigen value and accounted for 58.2% of variability. The total content value had strong relationship with Malonyl genistin content value. Acetyl isomers had strong relationship, but Malonyl isomers were only related to isomers except Malonyl glycitin. These results will help in research on soybean varieties to enhance isoflavone ingredients.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.386-392
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• 2016

This study investigated the isoflavone content, total phenol content, antioxidant activities (DPPH radical scavenging and oxygen radical absorbance capacity) and ${\beta}$-glucan content of defatted soybean extracts by bioconversion. Soybean was fermented with Lentinula edodes using submerged liquid fermentation system. Defatted soybean powder prepared by hexane (HDS; hexane defatted soybean) and ethanol (EDS; ethanol defatted soybean). The major components of non-fermented HDS (NFHDS) and EDS (NFEDS) were glucoside, such as daidzin, glycitin and genistin. During the bioconversion processing, isoflavone glucoside converted into aglycone such as daidzein, glycitein and genistein. The highest total isoflavone contents of fermented HDS (FHDS) were $2577.96{\mu}g/mL$, and the lowest total isoflavone contents of NFEDS were $428.27{\mu}g/mL$. The highest total phenol contents of fermented EDS (FEDS) was 42.34 mg GAE/g. DPPH radical scavenging and ORAC value were 31.30 to 59.92% and 247.48 to $786.36{\mu}M\;TE/g$ in non-fermented defatted soybean and fermented soybean, respectively. ${\beta}$-Glucan contents were 0.09 to 0.11% in non-fermented defatted soybean and fermented soybean, respectively. These results indicate that fermented soybean could be used as natural antioxidants for the development of functional foods.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.448-455
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• 2004

Changes in quality characteristics of Bijijang (fermented soybean curd residus) prepared at $35^{\circ}C\;and\;40^{\circ}C$ for 0, 12, 24, 36, and 48 hr were investigated. Acidity of Bijijang increased, whereas pH and Hunter's color values decreased during fermentation. Immediately after Bijijang preparation, ${\alpha}-and\;{\beta}-amylase$ activities were very low, ${\beta}-Amylase$ activity during fermentation increased rapidly, with those fermented at $40^{\circ}C$ higher than at $35^{\circ}C$. Neutral pretense activity was significantly higher than acidic pretense activity, and increased gradually after 12 hr. Change in total nitrogen content in Bijijang was insignificant, whereas contents of amino-type and water-soluble nitrogens increased significantly during fermentation. Major free amino acids of Bijijang were Arg, Pro, Glu, Thr, Ser, and Lys at initial fermenting stage, and, as fermentation progressed, contents of Cys, Met Glu, Ile, Leu, and Phe increased. Reducing sugar contents of Bijijang fermented at $40^{\circ}C$ were higher than those fermented at $35^{\circ}C$. Sucrose content decreased and glucose content increased. Glucoside (genistin and daidzin) contents decreased and aglycone (genistein and daidzein) contents increased during preparation of Biji and fermentation of Bijijang. Contents of free sugars and isoflavones were higher in Bijijang fermented at $40^{\circ}C$ than at $35^{\circ}C$. Based on these results, fermentation at $40^{\circ}C$ for 48 hr was determined to be optimum fermentation condition for Bijijang.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.239-247
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• 2018

Soybean produces three major types of isoflavones, daidzein, genistein, and glycitein aglycones and their glucosides and malonylglucosides. It has been known that malonylated glucosides are rapidly converted to their corresponding aglycones due to the unstable thermolabile glucoside malonates; therefore, the analytical study of malonylated glucosides has been insufficient. In this study, we analyzed the malonylglucoside content in soybean seeds. Isoflavone analysis of three soybean cultivars revealed that 81.5~90.0% of the total isoflavones were malonylglucosides, whereas aglycones were rarely detected. Moreover, the total isoflavone content increased during a 5-day germination period where growth regulators and coumaric acid treatments tended to yield higher isoflavone content than the normal germination treatment, however the differences were not significant; notably, the isoflavone accumulation trend continued with additional germination days. The content of malonylglucoside was higher than that of other isoflavones, which was 83.7~86.6% of the total isoflavone content in seeds with a 3-day germination period. Furthermore, isoflavones were significantly accumulated in the hypocotyl of seedlings with a 5-day germination period. The content of isoflavone in the hypocotyl of the Pungsannamul-kong was 10,240 ug/g when treated with coumaric acid, which was considerably higher than that of other cultivars and treatments. Additionally, soybean seeds heated at $60^{\circ}C$ for 1 hour produced higher isoflavone content than non-heated soybean seeds. Our results show that it is possible to increase the isoflavone content in soybean seeds through various treatments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.322-330
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• 2018

The correlation between the nutritional composition of soybeans and whole soymilk palatability was investigated using nine soybean cultivars (Teagwangkong, Daewonkong, Saedanback, Jinpung, Daechan, Miso, Cheongmiin, Cheongja 3, and Socheongja). Physicochemical analysis of soybeans, showed that the protein and lipid contents were 37.7-46.0 and 15.2-20.9%, respectively. Unsaturated fatty acids were 81.1-84.8% of total fatty acids, of which linoleic acids was 49.7-56.8%. Total tocopherol was $243.5-361.3{\mu}g/g$ of extract, of which ${\gamma}$-tocopherol was $67.14-86.49{\mu}g/g$. Total isoflavone contents varied within cultivars from $495.4-1,443.8{\mu}g/g$ of extract. Daidzin and genistin were 252.1-556.0 and $241.8-730.7{\mu}g/g$, respectively, which were major isoflavones in soybeans. For the sensory evaluation, whole soymilk was made from nine soybean cultivars and 20 panels investigate its palatability. The Daechan cultivar had the highest (9.1), and Cheongmiin the lowest (5.6), overall palatability score. Interestingly, sensory results were strongly correlated with linoleic acid (0.746) and stearic acid (-0.716) content. In summary, the fatty acid composition of soybeans is the key factor in determining the palatability of whole soymilk. This study could be applied to determine the suitability of cultivars for soybean products, including whole soymilk.