• 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.

• 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 Plant Resources
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• v.27 no.6
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• pp.610-621
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• 2014

Phenolic compounds such as isoflavones contribute to the antioxidant properties of soybean. This study investigated differences in the phenolic content and antioxidant activity of ten soybean cultivars grown in two different locations in Korea. We observed a wide range of variation in total isoflavone and phenolic content by location and cultivar. The total isoflavone content of cultivars grown at Pyeongchang (sub-highland) was significantly higher than that in cultivars grown at Gangneung (lowland). In contrast, the total phenolic content of cultivars grown at Gangneung was greater than that of cultivars grown at Pyeongchang. The radical scavenging activity of DPPH was similar to that of the total phenolic content rather than that of the total isoflavone content. These results suggest that antioxidant activity of soybean was associated with phenolic compounds rather than isoflavones. To identify the individual antioxidant components, we used an on-line HPLC-$ABTS^+$-based assay system, ESI/MS, and NMR. The results showed that the strongest antioxidant activity was linked to epicatechin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.96-101
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• 2013

This study was carried out to investigate the changes in antioxidant activity, and the isoflavone and free amino acid content in fermented tofu of the ingredients of kimchi (red pepper, garlic, ginger, and anchovies) and lactic acid bacteria (Pediococcus acidilactici KL-6) during 24 weeks of fermentation at $20^{\circ}C$. The total polyphenol content of various types of fermented tofu such as the control (tofu with kimchi ingredients mixture), tofu and kimchi ingredients with lactic acid bacteria (TL), and tofu in pre-fermented kimchi ingredients with lactic acid bacteria (TPL) ranged from 156.34 to 165.17 mg/g, showing that TPL was significantly higher in terms of fermentation time (6 weeks) compared to others. The DPPH free radical scavenging activity of TPL (84.11%) was higher than that of the control (76.68%) and TL (78.95%) after 12 weeks fermentation at $20^{\circ}C$. The changes of nitrite scavenging activity and SOD-like activity in the tested tofu showed the same tendency as the DPPH free radical scavenging activity during 14 weeks fermentation TPL showed statistically significant levels of increased antioxidant activity, so we compared the isoflavone and free amino acid content. The isoflavone and free amino acid content of TPL was 2.34 mg/g and 20.81 mg/g after 14 weeks fermentation, respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.443-448
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• 2005

Isoflavone content of soymilk prepared with germinated soybean significantly increased. Soymilk prepared with Shinpaldal-2 germinated far 12 hr showed maximum 5.552 mg/g isoflavone. Solid content in soymilk increased from 5.68 to 6.02% for Shinpaldal-2 and from 5.30 to 6.10% for Seomoktae with 24 hr germination. 'L' values of soymilk increased, whereas 'a' and 'b' values decreased. Viscosity of soymilk decreased, while stability increased as germination time increased up to 24 hr, Organoleptic flavor properties of soymilk improved, showing decrease in benny and increase in savory flavors. Acceptance test showed soymilk prepared with 12 hr germinated Shinpaldal-2 showed highest acceptance, while Seomoktae soymilk showed least.

• Journal of the Korean Society of Food Culture
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• v.23 no.6
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• pp.801-811
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• 2008

The principal objective of this study was to assess the effects of soy isoflavone supplementation on bone mineral density in 36 female college students with osteopenia for 12 weeks. The subjects were divided into three groups on the basis of bone mineral density. The experimental groups were provided supplements of either 80 mg of isoflavone (Iso-80) or 40 mg of isoflavone (Iso-40). To the placebo group, 40 mg of powdered glutinous rice was administered. It was determined that many subjects with osteopenia evidenced lower levels of activity as compared to the control group. Isoflavone supplementation was more effective in controlling total cholesterol and LDL-cholesterol than was observed in the placebo group. We noted no significant differences in serum osteocalcin concentration between Iso-40 and the placebo group, but significant differences in osteocalcin concentration were detected between Iso-80 and the placebo group. Bone quality indices (BQI) were correlated positively with mineral content, lean body mass, muscular mass, and blood components including albumin, Ca, Mg, ALPase, and osteocalcin. Both Iso-40 and Iso-80 supplementation for 12 weeks significantly increased protein and mineral content in the body. As lower intakes of Ca and folate were noted in the subjects, emphasis should be given to adequate intakes of these nutrients in the subjects. In conclusion, 12 week isoflavone supplementation in young females with osteopenia exerted positive effects on bone mineral density and bone turnover markers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.373-383
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• 2012

Soybean, C.V. Daewonkong, was planted on 25 May and 25 June in 2011, and four temperature gradient, control (ambient temperature in field plot), control + $3^{\circ}C$, control + $4^{\circ}C$, and control + $5^{\circ}C$, were artificially created by controlling the green house system. The obtained results indicated that vegetative growth of soybean plant was beneficially facilitated by planting on May (PM) than planting on June (PJ). The 100-seed weight was significantly higher in PM, and positively affected by increasing temperature, whereas the weight was reduced in control + $5^{\circ}C$ plot. Isoflavone content and fatty acid composition were analyzed to determine the effects of plating date and growth temperature. Isoflavone content was higher in PJ plot ($1479.8{\mu}g/g$) than in PM plot ($1201.8{\mu}g/g$), however, the influence of growth temperature varied with planting date. The composition of oleic acid was positively affected by increasing temperature, whereas the proportions of linoleic and linolenic acid were reduced. The numbers of node was considered as a major variable in the regression equations estimated using forward stepwise regression analysis for isoflavone content and unsaturated fatty acid under different environmental conditions.

• Korean Journal of Community Nutrition
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• v.9 no.1
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• pp.38-46
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• 2004

Few studies have conducted the bone health benefits of usual dietary isoflavone intake in Korean college-student women. To elucidate this benefitial effects and correlations between dietary isoflavone and nutrients intake and bone formation marker (ALPase, osteocalcin), questionnaires, anthropometric measurements, serum mineral (Ca, P, Mg) concentrations were analyzed. Fifty three subjects were used in this study. The average age, height, body weight, BMI, body fat content and triceps skinfold thickness were 21.43 year, 161.07 cm, 52.81 kg, 20.48 kg/$m^2$, 20.72% and 17.59 mm respectively. Soy food intake frequencies were soybean > soybean curd > soypaste stew > soybean milk. The average calorie, protein and Ca intake were 1766.21 $\pm62.54 kcal\;66.45\pm2.00 g\;and\; 549.62 \pm 27.55 mg$ respectively. Serum ALPase activity and osteocalcin concentration were 115.74$\pm3.6u/L$ and 7.15 ng/$m\\ell$ respectively. Usual dietary isoflavone intake was positively related to calory, protein, Ca, P intake and serum Ca, Mg concentration. Serum osteocalcin concentration was negatively correlated with isoflavone intake ($r^2$=0.28, p < 0.05). In these results, usual dietary isoflavone can support an additive effect to bone health and Ca nutrition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.108-111
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• 2005

Studies were conducted to develop new breeding resources using wild soybean (Glycine soja Sieb. & Zucc.) species. In 132 wild soybeans, the average crude protein content was $45.4\%$, ranged from $37.4\%\;to\;50.2\%$ and average crude oil content was $9.3\%$ showing lower than cultivated soybean. The average total amino-acids content was $19,214\;{\mu}g/g$, containing $252\;{\mu}g/g$ of methionine and $103\;{\mu}g/g$ of cysteine, a sulfur containing amino-acid. In ratio of individual amino-acids, the glutamic acid, methionine and cystein content was $16.1\%,\;1.3\%,\;and\;0.5\%$, respectively. The correlation between total amino-acid and sulfur containing amino-acid was not significant. Total isoflavone concentration was, on average, $1,105\;{\mu}g/g$ in wild soybean germplasm. As a result of comparison with total isoflavone and genestein contents, significant positive correlations were observed between total isoflavone and genistein concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.359-365
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• 2006

Changes in isoflavone and oligosaccharides, and some physicochemical properties of Chokong, a pickled and dried soybeans, were investigated during pickling in brewed vinegar at $20^{\circ}C$. The used soybeans were 24 hr germinated soybeans, which was maximumly increased in isoflavone content during germination. The isoflavone contents were significantly increased by approx. 80% in both glycosides and aglycone type of isoflavone after 20 day of pickling at $20^{\circ}C$. The isoflavone values of germinated Chokong were significantly higher than those of ungerminated ones. Pickling the soybeans in vinegar resulted in a rapid initial decrease in oligosaccharides, Particularly in raffinose and stachyose. The pH and soluble solids contents in vinegar increased markedly and L values decreased during initial pickling of 24 hr.