• Food Science and Biotechnology
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• v.18 no.2
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• pp.488-493
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• 2009

A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.141-146
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• 1998

Production of medicinal soybean [Glycine max (L.) Merrill], characterized with black seed, white stripe at hilum border, yellow cotyledon and small seed, is increasing with increasing consumption. The objective of this study was to investigate the chemical composition of medicinal soybean seed and to provide basic information, for the characterization of these soybeans among genetic resources. Forty-four lines of medicinal soybeans collected from Korea and two control cultivars, 'Hwangkeumkong' (Yellow seed coat) and 'Geomjeongkong l' (Black seed coat) were planted at the Research Farm of the College of Natural Resources, Korea University, located at Namyangju City on May 25, 1996. Seeds of these lines were harvested at full maturity and analyzed for protein, oil, sugar, starch and mineral contents. Mean protein and oil content of the medicinal line seeds were 42.6 and 16.1%, respectively, and those of the control cultivars were in the middle range for protein and oil content. However, sugar and starch content of the medicinal line seeds appeared to be in the lower range of the distributions compared to the control cultivars and were 10.0 and 1.68%, respectively. Mean P, K, Ca, and Mg contents of the seeds of medicinal soybean lines were 15.9, 21.5, 3.11, and 2.81 mg/g, respectively, indicating that these lines had higher P, K, and Mg and lower Ca contents when compared to the control cultivars. Mean Na and Fe contents were 671 and 224 mg/kg, respectively, showing lower Na and similar Fe contents. The observed results provided that chemical compositions of medicinal soybean were, on average, different from those of the general soybean cultivars.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.971-980
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• 2019

We profiled the health-promoting bioactive components in nine types of soybean seeds with different seed coat colors (yellow, green, brown, and black) and investigated the effects of different extraction solvents (methanol, ethanol, and water) on their antioxidant activities. The carotenoid and anthocyanin compositions varied greatly by seed color, and the phenolic acids, total phenol, and total flavonoid contents differed by genotype. The carotenoid content was relatively higher in soybean seeds with green and black seed coats than in those with a yellow seed coat while lutein was the most plentiful. The anthocyanin content was considerably higher in the soybean seed with the black seed coat. The results of the DPPH assay showed strong antioxidative activities in the methanol- and water-extracts compared to the ethanol-extract, irrespective of the seed coat colors. Moreover, the soybean seeds with the black seed coat exhibited the highest antioxidant activity among the samples, regardless of the extraction solvent used. Eighteen bioactive compounds were subjected to data-mining processes including principal component analysis and hierarchical clustering analysis. Multivariate analyses showed that brown and black seeds were distinct from the yellow and green seeds in terms of the levels of carotenoids and anthocyanins, respectively. These results help our understanding of the compositional differences in the bioactive components among soybean seeds of various colors, providing valuable information for future breeding programs that seek to enhance the levels of compounds with health benefits.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.239-248
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• 2007

Although high nutritional values and continuous identification of important functional substances of soybean [Glycine max (L.) Merrill.] promote consumption of soybean products worldwide, informations on quality of brand soybean is not enough for consumers. Total of 100 brand soybeans [32 for soypaste and source, 45 black testa (lage), and 17 black testa (small) or medicinal soybean and beansprout soybean] were collected at supermarkets and several external quality factors were analyzed. Brand soybeans were marked with the environmental friendly and intimating words along with soybean (white or yellow), black soybean (black-, frost-, late frost-, green or inner-green-), medicinal soybean and beansprout soybean. Among 100 brand soybeans 30% was 1 kg package and 59% was 500 g package, difference between printed and actual weights of 70% brand soybeans was ${\pm}1%$ and weights of 2/3 of brand soybeans were higher than printed weight. Range of 100 seed weights of soypaste and source, black testa (large) and black testa (small) and beansprout soybeans were $23.7{\sim}47.8g$, $21.9{\sim}44.5g$ and $9.5{\sim}15.0g$, respectively. Although ranges of 100 seed weights of soypaste and source and black testa (large) soybeans were similar, 63% of soypaste and source were less than 29 g, while 78% of black testa (large) soybeans were higher than 30 g. Although average and highest percentages of seeds separated with 6.7 mm sieve were similar with 87.4% and 99.9% for soypaste and source soybean and 86.5% and 99.5% for black testa (large) soybean, respectively, the lowest percentages were 70.7% for soypaste and source soybean and 14.4% for black testa (large) soybean. When 100 seed weight was greater than 35 g, 90% of seeds were remained on 6.7 mm sieve. On the other hand 100 g weight and percentage of seeds remained on 6.7 mm sieve showed significantly positive correlations [r=0.7488** for soypaste and source soybean and r=0.7874** for black testa (large) soybean when 100 seed weight was $20{\sim}30g$. Based on hilum color and/or appearance, 76% of brand soybeans collected (more than 90% in yellow testa soybeans) were found to be mixed more than 10% with other cultivars or landraces. Foreign materials such as sand, piece of clothe, wood piece, dead insects, other soybeans were found in 20% of brand soybeans. Average test weight of brand soybeans was 762g $L^{-1}$ with a range of $645{\sim}820g\;L^{-1}$. Soybeans from local markets were as good as brand soybeans in 100 seed weight, uniformity of seeds, weight of foreign materials and test weight.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.558-577
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• 2020

Isoflavone contents in soybean seeds are affected by both genetic and environmental factors. Correlation analysis between these factors and isoflavone contents are considered as valuable inputs when breeding improved soybean cultivars. In this study, the seeds of 49 soybean accessions grown in Korea were grouped as black, yellow, green, yellowish-green, pale yellow, and green with a black spot based on their seed coat colors. The contents of 12 isoflavones were analyzed and the association between isoflavone content and seed coat color was determined. The accessions were also grouped as early, intermediate, and late-maturing based on their days to maturity. Out of the 12 isoflavones, 11 were found in 2 accessions, 9 in 18 accessions, 8 in 11 accessions, 7 in another 11 accessions, and 6 in 7 accessions. The total isoflavone content (TIC) in black, yellow, green, yellowish-green, pale yellow, and green with black spot soybeans was in the ranges 2.110 ~ 5.777, 2.487 ~ 4.733, 2.185 ~ 4.413, 2.681 ~ 4.065, 1.827 ~ 4.085, and 3.376 ~ 4.133 mg/g, respectively. The average TIC was highest in green with black spot soybeans (3.616 mg/g), and lowest in pale yellow soybeans (2.875 mg/g). Besides, the average TIC was lowest in early maturing accessions compared to late- and intermediate-maturing accessions. TIC was strongly correlated to malonylgenistin (r = 0.91) and malonyldaidzin (r = 0.78) contents, and poorly correlated to glycitein (r = 0.04) and malonylglycitin (r = 0.18) contents. Also, days to maturity showed strong correlation with malonylgenistin (r = 0.47) content and TIC (r = 0.38). The principal component analysis outlined accessions with high TIC and diverse isoflavones along the first and second components, respectively. The results of the present study depicted that green soybeans with a black spot could be sources of high TIC. Furthermore, late-maturing accessions with diverse isoflavones in their seeds could be useful in future agricultural systems in Korea.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.215-221
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• 2011

The goal of this study was to evaluate the quality characteristics of various beans in distribution. The quality characteristics investigated were proximate composition, color, free sugars, organic acids, amino acids, and minerals. Bean samples analyzed were white soybeans (Glycine max. (L.) Merrill), kidney beans (Phaseolus vulgaris var. humilis), black soybeans (Glycine max (L.) Merr.), black small soybeans (Rhynchosia nulubilis), sword beans (Canavalia gladiata), and green beans (Phaseolus vulgaris). The highest contents of crude fat and crude protein were 17.60${\pm}$0.14% for white soybeans, and 42.38${\pm}$0.15% for black soybeans, respectively. Higher color values compared to the other samples were $L^*$ (64.07${\pm}$0.97) for sword beans, $a^*$ (15.64${\pm}$0.48) for kidney beans, and $b^*$ (22.92${\pm}$0.09) for white soybeans. The highest contents of sucrose, oxalic acid, and malic acid in black small soybeans were 54.23 mg/g, 23.26 mg/100 g and 18.24 mg/100 g, respectively. Xylose, galactose, lactose, malonic acid, succinic acid, and lactic acid were not detected in the soybeans studied, whereas the glutamic acid content of soybeans ranged from 2.68 to 6.18 g/100 g. Levels of K and Mg contents in soybean were higher than those of the other minerals.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.326-336
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• 2023

Growth and seed productivity of black soybean (cv. Cheongja-3ho) sown on four different dates were investigated in paddy fields in the southern region to cope with climate change, trends in consumption of soy foods, and the spread of double cropping region. Sowing date of black soybean showed a significant correlation with above-ground growth, seed yield, useful components, etc. When sown in May, the above-ground part was plentiful, while seed yield significantly decreased. On the other hand, when sown in June and July, reproductive growth was vigorous resulting in high seed yield, exceeding 200 kg/10a, and pod injury and seed coat cracking were reduced. Furtherm ore, the isoflavone content of seed increased significantly as the sowing date was delayed. These results suggests that sowing from early June to early July is appropriate. Nevertheless, late June sowing oppears the m ost appropriate for black soybeans in the southern paddy fields, in order to avoid a risk of overlapping with sowing dates of winter crops in the double cropping.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.80-87
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• 2009

Aiming at development of region specialized crop, this study was conducted to clarify variety and cultivation region dependent on antioxidative compounds in black soybean seeds. For this purpose two black soybean varieties (Ilpumgeomjeongkong and Cheongjakong) were cultivated in 3 different regions (Hwaseong in Gyeonggido, Naju in Jeollanamdo and Jinju in Gyeongsangnamdo) in 2004 and 2005, and harvested seeds were used for isoflavone, anthocyanin and tocopherol contents along with electron donating ability-based antioxidative activities measurements. 100 grain weight between two varieties were not significantly different, but Hwaseong district showed higher 100 grain weight compared to Jinju and Naju. Ilpumgeomjeongkong was higher total isoflavone content ($1,064.9{\mu}g/g$) compared to Cheongjakong ($801.3{\mu}g/g$) in 2004, whereas Cheongjakong showed higher in 2005 compared to Ilpumgeomjeongkong. The highest isoflavone content was obtained in Hwaseong district in 2004, whereas it is the reverse in 2005 that Jinju district showed the highest isoflavone content. In total anthocyanin content, Ilpumgeomjeongkong (7.22 mg/g) was higher than that of Cheongjakong (6.83 mg/g), and Jinju district showed the highest total anthocyanin content (9.16 mg/g) compared to Naju and Hwaseong cultivating districts in their three cultivating districts. Total tocopherol content showed no significant difference between two varieties, but Hwaseong ($217.2{\mu}g/g$) and Jinju ($216.3{\mu}g/g$) districts showed higher content compared to Naju ($189.7{\mu}g/g$) among three cultivating districts. In tocopherol content ratio, $\gamma$-tocopherol was the highest from 56.2% to 59.9%. In electron donating ability (EDA) between two cultivars, Ilpumgeomjeongkong was significantly higher than Cheongjakong, and Naju was the highest of 55.6% among three cultivating districts.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.357-372
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• 2011

We carried out the experiment to select the suitable sprout soybean varieties for environment-friendly cultivation in paddy field of southern part area, compares of excess moisture injury degree and yield ability among 29 sprout soybean varieties. Plant growth of sprout soybean was generally low in beginning and recovered after flowering due to rainfall. In paddy field cultivation, number of pod per individual and number of seed per individual were less in difference than upland cultivation, and maturing date was delayed 5-14 days than upland cultivation in most species. When environment-friendly cultivation, pest injury was not caused major problem for the growth during the vegetative period of soybean due to ground spider as natural enemy to insect pest. However, damage of stink bugs showed severe during grain filling period, and Dawonkong, Anpyeongkong, Dachaekong and Wonhwangkong showed susceptible to sting bug. SMV infection was weak and showed some necrosis symptoms in Sokangkong, but black root rot was not infected at all. Bacterial pustule began to be infected slowly from pod enlargement stage in most species, displayed severe symptoms in Dawonkong, Pungsannamulkong, Seonamkong and Sobaeknamulkong. The symptoms of pod anthracnose, pod blight and purple spot were greatly appeared after flowering. Disease resistance varieties was Paldokong, Kwangankong, Doremikong, Somyeongkong, Pungsannamulkong, Iksa-namulkong, Seonamkong, Sojinkong, Pureunkong, Bosugkong, Namhaekong and Sorokkong. Lodging index showed 3 in Saebyeolkong, and other species displayed slight lodging in 0-3 degree. 100-seed weight is 9.8-17.2g extent and increased 0.1-3.7g than upland cultivation in most species, but decreased in some species. Government purchase standard, species correspond to small-seed-size namulkong (Sizing screen diameter 4.0-5.6 mm) was Dawonkong, Dachaekong, Bosugkong, Seonamkong, Sokangkong, Hannamkong, Somyeongkong and Wonhwangkong. Species which seed yield was higher than Pungsannamulkong (266kg/10a) were Sorokkong, Hannamkong, Bosugkong and Sowonkong. Considering sprout soybean species, disease endurance, insect resistance, lodging resistance, 100-seed weight, yield ability and excess moisture tolerances synthetically, Seonamkong, Hannamkong, Doremikong, Bosugkong, Pungwonkong, Kwangankong, Sowonkong, Dagikong, Paldokong, Eunhakong and Pungsannamulkong were promising for environment-friendly cultivation in paddy field.