• Preventive Nutrition and Food Science
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• 제4권3호
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• pp.193-196
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• 1999

To investigate the effect of yam on the activity of benzo[a]pyrene hydroxylase(BPH), the key enzyme associated with polycyclic aromatic hydrocarbons(PAHs) metabolism, rats were fed a fiber free diet for 7 days, whereupon they were switched to experimental diets for another 7 days. Diets contained benzo[a] pyrene(BP, 400 mg/kg diet) and 25% or 50% yam powder (freezer dried and hot air dried ). Diets containing pectin and cellulose were compared with diets containing yam. BPH activities were assessed in the liver, lung, kidney, stomach, small intestine and large intestine of rats. BP induced BPH activities in various tissues ; 8 fold in liver, 28 in lung and stomach , and 32 in large intestine. The addition of yam significantly lowered BPH activity in liver, lung and stomach and hot air dried yam was nmor eeffectivie than freeze dried yams. These data suggested that yam containing diet may influence carcinogen metabolism in liver and extrahepatic target tissues by altering activities of BPH and may reduce exposure of these tissues to dietary carcinogens.

• 한국환경보건학회지
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• 제33권2호
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• pp.137-144
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• 2007

Yam, Prunella was stepwise extracted with hexane, chloroform, ethyl acetate, butanol, and water. Anti-microbial activity of each extract was investigated. Hexane extract was tested for anti-microbial effect on Streptocaccus mutans, one of causative factor of dental caries. Methanol extracts of 7 plants were investigated to anti-microbial effects on S. mutans KCTC 5316, P. gingivalis KCTC 5352, S. aureus KCTC 1927 by means of agar diffusion method. Methanol extract of Yam and Prunella revealed anti-microbial activity against S. mutans, P. gingivalis, and S. aureus. Also, hexane fraction of Yam revealed anti-microbial activity against S. mutans. In sequence of hexane, chloroform, ethylacetate, butanol fraction by Prunelia acted as potent anti-microbial agent on P. gingivalis. The measured MIC of hexane fraction of Yam and Prunella on S. mutans KCTC 5316 strain was 0.25 mg/ml and 0.5 mg/ml and the MIC of hexane fraction of Prunella on S. aureus was 0.5 mg/ml. The hexane fraction of Yam and Prunella suppressed viable ceil counts(VCC) of S. mutans, especially after 24 hrs. The Prunella hexane fraction suppressed VCC of S. aureus, after 12 and 24 hrs. Tested concentrations were 0.1, 0.25 and 0.5 mg/ml. the results were compared with control (0 mg/ml). The pH of S. mutans media and GTase activity were determined to evaluate the anticariogenic activity of Yam, Prunella hexane fraction. The pH were increased from 5.6 to 7.0-7.2 in concentration of 2.0 mg/ml. Yam hexane extraction revealed 35% inhibition to GTase activity and Punella inhibited 25% of GTase. These results suggest that the hexane extracts of Yam and prunella have Antibacterial activities against S. mutans, P. gingivalis, S. aureus and have preventive effect on dental caries.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.240-244
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• 2006

To develop a health-aid preparation of Chinese yam (Dioscorea batatas Decne), lactic acid fermentation was attempted using a mixed starter comprising of Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidus. The anaerobic fermentation of a 5% Chinese yam flour suspension gave a uniform suspension of pH 4.35, containing $7.76{\times}10^6 CFU/mL$ lactic acid bacteria (LAB), and which was found to be acceptable to the panel from a sensory assessment. During the administration of the lactic acid fermented (LAF) Chinese yam to Sprague Dawley rats for 6 weeks, a smaller body weight gain, but greater excretion of feces were observed, implying the creation of a healthy gastrointestine on the administration of LAF Chinese yam, which was also confirmed by the gastrointestinal motility of the feed in rats fed on LAF Chinese yam. The constipation induced by loperamide was further suppressed in a rat group fed on a LAF Chinese yam diet, which was qualified from healthy gastrointestinal flora established by LAB. A serochemical analysis revealed a slight improvement in the blood glucose, neutral lipid and total cholesterol concentrations on administration of LAF Chinese yam, suggesting LAF Chinese yam could be served as a healthy-aid preparation, even for hyperglycemia or hyperlipidemia patients.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.194-203
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• 2014

Yam (Dioscorea batatas) is widely consumed as functional food for health promotion mainly in East Asia countries. We assessed whether yam root (tuber) or bark (peel) extracts stimulated the activity of osteoblasts for osteogenesis. MC3T3-E1 cells (mouse osteoblasts) were treated with yam root extracts (water or methanol) (study I) or bark extracts (water or hexane) (study II) within $0{\sim}10{\mu}g/mL$ during the periods of osteoblast proliferation (5~10 day), matrix maturation (11~15 day) and mineralization (16~20 day) as appropriate. In study I, both yam root water and methanol extracts increased cell proliferation as concentration-dependent manner. Cellular collagen synthesis and alkaline phosphatase (ALP) activity, both the indicators of bone matrix protein and inorganic phosphate production for calcification respectively, were also increased by yam root water and methanol extract. Osteoblast calcification as cell matrix Ca and P accumulation was also increased by the addition of yam root extracts. In study II, yam bark extracts (water and hexane) increased osteoblast proliferation and differentiation, as collagen synthesis and ALP activity and osteoblast matrix Ca and P deposition. The study results suggested that both yam root and bark extracts stimulate osteogenic function in osteoblasts by stimulating bone matrix maturation by increasing collagen synthesis, ALP activity, and matrix mineralization.

• 식물병연구
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• 제23권1호
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• pp.82-87
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• 2017

During 2012 to 2014, a survey for the presence of viral diseases in yam plants was carried out in a field of the Institute for Bioresources Research in Gyeongsangbuk-do, Korea. A total of 88 leaf samples were collected and tested by reverse transcription polymerase chain reaction using specific primer sets. Eighty-one samples were positive for Broad bean wilt virus 2 (BBWV2), Chinese yam necrotic mosaic virus (ChYNMV), Cucumber mosaic virus (CMV), Japanese yam mosaic virus (JYMV), and Yam mild mosaic virus (YMMV), whereas Yam mosaic virus (YMV) was not detected. Additionally, seven samples were negative for all viruses. Several samples exhibited mixed (double and triple) infections. Three viruses (CMV, JYMV, and YMMV) were detected for the first time in yam plants in Korea. A BLAST search showed that three viruses shared nucleotide identities with CMV-Ca (98%), JYMV-O2 (91%), and YMMV-TG_NH_1 (86%). Thus, our findings confirmed that yam plants cultivated in Korea were infected with multiple viruses with three of these viruses reported for the first time in Korea.

• 동아시아식생활학회지
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• 제19권6호
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• pp.1032-1038
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• 2009

This study describes the production of functional Ssukgaen Dduk though the addition of yam and mugwort to Goami 2, a healthy diet and diabetes. In this study, the rice is soaked for many hours and the particle size distribution of the rice was determined as a function of the water-soaking time. The produce Ssukgaen Dduk was repeated after the addition of varying concentration of yam. Non-glutinous rice was soaked for 4, 8, 12 hours and the Goami 2 rice was soaked for 4, 8, 12, 16, 20 hours and ground to a powder and passed through a 18~30 mesh sieve to determine the particle size distribution of the rice as a function of water-soaking time. Using this approach, optimal soaking time for Dduk was found to be 4 hours for non-glutinous rice(pass rate of 30 mesh: 58.29%) and 12 hours for Goami 2(pass rate of 30 mesh: 87.88%). When Ssukgaen Dduk made with Goami 2 rice powder only and those made with varying amounts of yam(10%, 20%, 30%, and 40%) were subjected to the sensory test, the control group(non-glutinous rice Ssukgaen Dduk) had the highest preference in general(3.73). Out of Ssukgaen Dduk containing yam, the S4 group, which contained 30% yam, had the highest preference(2.87) In addition the S4 group also had the highest extent of soft, and delicacy of texture general preference of S5, 40% the lowest(2.37), S1 only Goami 2 the hardness(112.59), as 91.46 lower (83.85) yam increased, the less hard the texture Ssukgaen Dduk. In conclusion Ssukgaen Dduk though the addition of mugwort and yam to the Goami 2 rice, it would be better to add 30% yam to 70% Goami 2 rice powder mixed with mugwort.

• Archives of Pharmacal Research
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• 제29권5호
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• pp.348-353
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• 2006

In this study, a 40% ethanol extract of Chinese yam flour (Dioscoreae rhizoma), containing $177{\pm}58{\mu}g/mL$ of dioscin, was tested in order to evaluate its pharmacological effects on the gastrointestinal tracts of Sprague-Dawley rats. Via the ingestion of the Chinese yam extract, the secretion of gastric acid was suppressed in the rats, and gastrointestinal motility increased by as much as 10%. The fecal quantity of rats fed on the Chinese yam extract also increased, by more than 40% as compared with that of the controls. The Chinese yam extract was found not to affect the growth of normal intestinal bacteria. However, a great deal of lactose-fermenting bacteria was observed in the fecal samples of rats fed for 6 weeks on 2% Chinese yam extract. This finding would appear to suggest that Chinese yam extract not only induces an improvement in digestive capability, but also affects the conversion of some intestinal flora to helpful bacteria. Our serochemical analyses indicated that serum glucose, neutral lipid, and total cholesterol levels were reduced to some degree by long-term feeding on Chinese yam extract. This finding bolsters the notion that Chinese yam extract may prove helpful as a digestion-aiding agent for patients suffering from hyperglycemia or hyperlipidemia.

• Preventive Nutrition and Food Science
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• 제18권4호
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• pp.249-255
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• 2013

Yam (Dioscorea) has long been used as foods and folk medicine with the approved positive effects for health promotion. Although consumption of yam products is increasing for health promotion, reports for the metal contamination in commercial yam powder products to protect the consumers are lacking. In this study, we aimed to assess whether the commercial yam powder products were heavy metal contaminated or not using the yam products from six commercial products from various places in South Korea. The contents of heavy metals (Cd, Cr, As, Pb, Ni, and Sn) in yam powder products were measured and compared to national and international food standard levels. Also, the metal contamination was monitored during the food manufacturing steps. The study results showed that the contents of heavy metals (Cd, Cr, As, and Pb) in yam powder products are similar to those in national 'roots and tubers' as well as in various crops. In comparison to three international standard levels (EU, Codex and Korea), Cd content in yam powder products was lower but Pb content was 5 times higher. Also, Pb, Ni, and Sn may have the potential to be contaminated during food manufacturing steps. In conclusion, the level of heavy metals (Cd, Cr, As, Ni, and Sn) except Pb is considered relatively safe on comparison to national and international food standard levels.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1103-1108
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• 2016

Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.

• 한국미생물·생명공학회지
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• 제39권2호
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• pp.153-160
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• 2011

본 연구에서는 무미, 무취의 생마로부터 생리활성과 관능성이 강화된 산약칩 가공제품 개발을 목표로, 사과, 오미자, 포도, 머루, 오렌지, 토마토, 홍삼 및 흑마늘 주스에 동결건조 생마절편을 침지하여 과실주스의 관능성분 및 유용활성 성분을 흡착시키고, 이를 다시 동결건조하여 산약칩을 제조하였다. 제조된 산약칩의 색차 (명도, 적색도 및 황색도), pH, brix, 산도, 총폴리페놀, 총플라보노이드, 총당, 환원당 함량 및 항산화 활성, nitrite 소거능을 평가한 결과, 산약칩은 동결건조한 생마절편에 비해 과일주스의 단맛과 상쾌함, 과일 색소로 인한 시각적인 관능성 증대, 총폴리페놀 함량 증가에 따른 항산화능 증대 등 유용생리활성과 관능성이 증가되었음을 확인하였다. 선호도가 높은 포도주스 산약칩 제조를 위한 최적 생마 침지시간을 평가한 결과, 120초 침지가 관능성 및 항산화능이 가장 증가되어 있음을 확인하였다. 향후, 다양한 과일주스 산약칩 제조를 위한 침지 및 제조조건의 최적화 연구 및 기호도 평가가 필요하다. 본 연구결과는 생마를 이용한 고부가가치 가공식품 제조의 기초자료로 이용될 것이며, 무미, 무취의 생마로부터 기능성과 관능성이 강화된 산약칩 가공제품 생산이 가능함을 제시한다.