• Food Science of Animal Resources
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• v.30 no.5
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• pp.773-779
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• 2010

The present study was designed to determine the physicochemical properties of yam (Dioscorea) solution fermented by L. bulgaricus, the protective effect of fermented Dioscorea opposita Thunb. on stomach lesions, and the possibility of its application to fermented dairy products. When the concentration of yam increased, the pH increased in raw powder samples but not in extracted powder samples. In 6% raw powder containing the sample, the viable cell counts showed a dramatic increase, whereas those in extracted yam powder significantly decreased in all concentrations during 32 h of fermentation. The viscosity of extracted yam powder showed a lower value than that of raw powder, which was maintained throughout the fermentation. The solution of Dioscorea opposita Thunb. raw powder showed a significantly higher allantoin content compared with the extracted powder (p<0.05). At 2% of added Dioscorea opposita Thunb., 0.65 mg/mL was contained in both samples; however, when 6% of Dioscorea opposita Thunb. was added, the amount of diosgenin increased up to 1.9 mg/mL. When 200 mg of powder/kg body wt. was injected, gastric lesions were apparently reduced compared with those of control rats. With 100 mg/kg body wt. injected into rats, the protective effect was a little lower than that in 200 mg/kg body wt. Based on these data, the present study indicated that yam powder fermented by L. bulgaricus showed a protective effect on gastric lesions in rats; therefore, it may be included as an added ingredient in yogurt manufacture.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.43-43
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• 2002

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.285-292
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea atata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. from about 150-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 140-days and continued to the 190-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.134-134
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• 2005

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.297-300
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• 2002

Endogenous ABA and batatasins were first quantified in the stored tubers and bulbils of the Chinese yam, Dioscorea opposita Thunb. cv. 'Tsukune' by GC-MS with comparison of internal standard, and sugar content was also analyzed by HPLC with comparison of external standard. Endogenous ABA content in stored tubers and bulbils was rapidly decreased as storage period prolonged. ABA content of the bulbils was always higher than that of tuber during storage periods. All batatasins of stored tubers and bulbils at 30 days after storage decreased steadily compared to 120 days after storage. On the contrary, batatasin-Ⅲ of the stored tuber and bulbils was only decreased at 60 days after storage. In Dioscorea opposita Thunb. cv. 'Tsukune' like D. japonica, D. alata, and D. bulbifera, may be controlled by endogenous batatasins and ABA, In these compounds, batatasins rather than ABA might be closely related to dormancy-inducing compound during dormancy of the Chinese yam, Dioscorea opposita Thunb. cv. Tsukune.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.257-279
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• 2009

Plants of genus Dioscorea have long been served as important carbohydrate-stuffed foods in the tropical and subtropical regions, and utilized as traditional herb medicines to enhance digestive function, improve anorexia, and treat diarrhea in oriental countries. It is known that around 600 species of Dioscorea are distributed in the world including 107 species in Asia, but actually utilized Dioscorea species are restricted to small numbers. Phytochemical investigations for Dioscorea species have revealed a number of chemical components such as sapogenins, saponins, phenanthrenes, stilbenes, diterpenes and purine derivatives. According to recent pharmacological studies, Dioscorea species possess significant antioxidant, antibacterial and anti-inflammatory activities as well as anticancer, antidiabetic, cholesterol-lowering and hypolipidemic effects. Here, seven Dioscorea species (D. batatas, D. japonica, D. bulbifera, D. opposita, D. tokoro, D. nipponica and D. alata), mainly distributed and used in Korea, China, and Japan, are reviewed to provide their botanical, phytochemical and pharmacological properties were described.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.69-74
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• 2012

This study was performed to determine by the ability of the mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus to ferment Dioscorea opposita Thunb. (yam) and to evaluate the nutraceutical value of fermented yam. The titratable acidity (TA) value increased from 2 to 6% with increased concentrations in both raw yam and extracted lactic acid bacteria (LAB) fermented yam (LFY). The viable cell counts and the allantoin and diosgenin contents were higher in raw LFY at large concentrations (6%) than in extracted LFY samples at all fermentation periods up to 32 h. Based on these data, it confirmed that raw yam fermented by the combination culture of L. bulgaricus and S. thermophilus for various fermentation periods favors the symbiotic growth of LAB and results in higher nutraceutical content.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.55-64
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea alata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. From about 50-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 40-days and continued to the 90-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.42-42
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• 2002

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.250-254
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• 2011

The study was carried out to evaluate the affect of proton beam radiation on production of bulbil and tuber including change of endogenous gibberellins, of Dioscorea opposita Thunb. The yield of bulbils and tubers from non- and irradiated D. opposita Thunb at doses of 5, 10, 15 and 20 Gy were determined. Endogenous gibberellins were also quantified by GC/MS analysis. D. opposita tubers irradiated at 15 Gy produced higher bulbil production than non-irradiated plants. Enlarged bulbil (above size diameter 4 mm) was significantly increased at 15 Gy. Bioactive endogenous $GA_4$ was dominant in bulbils and tubers irradiated with proton beam rather than $GA_1$. Major gibberellins biosynthetic pathways in bulbils and tubers of D. opposita plants were non C-13 hydroxylation route. From the results of this study, 15 Gy proton beam radiation was suggested as an optimal dose that can produce high amounts of bulbil for mass production of D. opposita plant.