• Korean Journal of Medicinal Crop Science
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• v.20 no.3
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• pp.190-194
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• 2012

Shoot tips of chinese yam (Dioscorea opposita Thunb.) were cultured on MS medium containing 0.5 mg/L BA to produce micro-tubers in vitro. To stimulate the formation of shoots and micro-tubers, and produce large micro-tubers, the sections of micro-tubers were cultured on MS media with BA and IAA. The shoot multiplication, and the micro-tuber formation and growth were very effective on the media containing 2.0 mg/L BA and 0.5~1.0 mg/L IAA. Sucrose added to MS medium with 2.0 mg/L BA and 0.5 mg/L IAA to stimulate more micro-tuber growth. The medium added 50 g/L sucrose was very effective in the increase of plant fresh weight and micro-tuber growth. After 4 weeks' culture of micro-tuber sections on the medium with 2.0 mg/L BA, 0.5 mg/L IAA and 50 g/L sucrose, the liquid media were added into the same vessels. The micro-tuber growth was stimulated remarkably by the addition of liquid medium. The addition of 25 $m{\ell}$ liquid medium containing 10 g/L activated charcoal, 3x MS salts and 250 g/L sucrose was the most effective in micro-tuber growth.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.24-27
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• 2001

This study was performed to analyse aroma patterns of Nagaimo, Ichoimo and Tsukuneimo by the electronic nose with 32 conducting polymer sensors. Response by the electronic nose was analysed by the principal component analysis(PCA). Sensory evaluation also for organoleptic taste and odor of Nagaimo, Ichoimo and Tsukuneimo was performed. Nagaimo was very crunchy and sweet. Tsukuneimo was roasted nutty, hard, viscid taste and sticky. Ichoimo had intensive unique yam flavor and moderate hardness between Nagaimo and Ichoimo. Intensity of Ichoimo for unique yam flavor by the electronic nose was the strongest. The quality factor(QF) of PCA for normalized pattern by thirty two sensors showed less than 2, and so aroma pattern of three yam cultivars had no difference. But when the PCA was performed for normalized pattern by eight selected sensitive sensors, the QF for Nagaimo and Tsukuneimo is 2.057. Thus aroma pattern between Nagaimo and Tsukuneimo could be distinguished.

• Food Science and Preservation
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• v.10 no.3
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• pp.320-325
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• 2003

This study was conducted to optimize sugaring process of yam for development of new snack product and enhancement acceptability. Three variables by five level central composite design and response surface methodology were used to determine optimum conditions for sugaring time, temperature and concentration. Optimization of the process was conducted using the combination of the moisture content, solid content, color and rehydration ratio. The regression polynomial model was suitable (P>0.05) model by Lack-of-Fit analysis with highly significant. To optimize the process, based on surface response and contour plots, superimposing the individual contour plots for the response variables. The optimum conditions for this process were 5.5 hours and 58％ at 40$^{\circ}C$ under the optimum of restricted variables as moisture content was 66 to 70, solid content was 25 to 30％, L value was above 75, a value was -2.1 to -2.4, b value was above 5 and rehydration ratio was 200 to 250.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.58-63
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• 1997

The experiment was done to clarify the effect of keeping material and storage temperature on weight and quality of Chinese yam (Dioscorea opposita) tuber. After the yam tubers were placed into the plastic boxes filled with different keeping materials [polyethylene (PE) film, hull, soil, sand, vermiculite], they were stored under different storage temperature(room, cold) from Oct. 15 to Mar. 15 when all the characters related to the tubers were measured. Soil or PE film as keeping materials was the lowest sound tuber rate when stored at room or cold temperature, respectively, while vermiculite was the highest in both storage temperature. When PE film and vermiculite in both storage temperatures were used as keeping materials, tuber weight were less reduced than the others. Brightness of chromaticity and moisture content were lower in room temperature storage than in cold temperature storage although the characteristics related to marketability were not affected by storage temperature. PE film had greater brightness and value 'a' of chromaticity but lower its 'b' value in the latter temperature than in the former temperature. Vermiculite, however, did the reverse result in comparison with PE film.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.125-130
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• 2018

In this experiment, we investigated the effects of various carbon sources and concentrations on the microtuber induction and acclimatization of the yam (Dioscorea cayenensis). First, the effects of the in vitro carbon sources and concentrations on the microtuber induction were examined. The highest efficiency of the microtuber induction was obtained in the 7% sucrose treatment, whereas the glucose treatment shows no effect on the microtuber formation. Secondly, the effects of the survival rate and the microtuber formation rate after the acclimatization were examined. The diameter (6.1 mm) and fresh weight (0.5g) of the tuberous root are the highest in the pretreatment of the 7% sucrose. Although the survival rate of the pretreatment of the low concentration sucrose (3% sucrose) is 100 %, the growth and development were inhibited. These results suggest the 7% sucrose treatment is appropriate for the yam microtuber formation and acclimatization. In addition, this protocol could be used for the propagation of virus- or disease-free clones and the multiplication of elite yam cultivars.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.232-236
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• 2006

This study was carried out to establish of hydroponic culture system for year-round mass production of yam and for supply of disease-free seed tubers from the superior yam species. There were not difference in tuber weight between 9 hrs photoperiod(640mg) and natural photoperiod(600mg). However, longer photoperiod than 9 hrs such as 12 hrs and 15 hrs decreased tuber weight to 490 and 500g, respectively, which sugested that long photoperiod showed adverse effect for tuber enlargement. Tuber enlargement of Dioscorea opposite according to ionic strength was higher at 50% nutrient of Sanyak's standard solution. The optimal concentration of NAA for the best tuber growth showed at 100mg/L as a 560mg while control showed a relatively lower tuber growth(350mg).

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.60-67
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• 1981

The run-off experiment plots had been established for eight sets of plot comprising four treatments with two replications on $20^{\circ}$ slope land having the Wait-A-Bit Clay soil(locally known), at the Olive River Soil Conservation Centre, Trelawny in Jamaica. The location of plots was about 820 metres m.s.l. and sloped north-west. Each plot size was determined as $40m^2$ having 2.7 m wide and 15.8 m long along slope. All of the run-off soil and water were collected by using the receiving tanks through the collection troughs and conveyance pipes. These run-off materials were measured and sampled, dried and computed for determination of the soil loss from each treatment of plots. During the first period of experiment for about 10 month which was one crop-year cycle of yam crop, total amount of 1,295 mm rainfall received. The heaviest daily rainfall was recorded as 116.2 mm on August 5 followed by 100.4 mm on August 6, 1980. The soil sediment had been collected and analysed for eleven times during this experiment. Total amounts of soil sediment as over-dried weight by the treatment plot were estimated as 182 ton/ha from treatment I, 105 tons/ha from treatment II, 50 tons/ha from treatment III, 43 tons/ha from treatment IV respectively. It is recommendable at present that the treatment III and IV measure which treated with contour mounds with the hillside ditch and grass buffer strip should be adopt4ed for hillside farming particularly with yam cultivation in Jamaica.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.591-594
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• 1999

An instrumental analysis of Sanyakbyung was carried out along with sensory evaluation to find out how its quality characteristics changed by the addition of glutinous rice flour(0%, 10%, 20%, 30%, 40% and 50%). The moisture content of Sanyakbyung decreased in proportion to the increment of glutinous rice flour. In terms of color, L-value increased depending on the increment of glutinous rice whereas a-value and b-value showed a decrease. This could be accounted for by two factors: one is that the protein contained in yam flour contributed to black coloring and the other is that the color of yam flour itself contributed ostensively to the tint of blackish coloring, and also to the tint of yellow and red coloring. ln the two bite compression test, the hardness, gumminess, chewiness, and cohesiveness of Sanyakbyung decreased depending on the increment of glutinous rice flour. The springiness did not show any significant variation among the samples. That is, the more yam flour was added, the more cohesive and gummy Sanyakbyung was produced. There were significant differences(p<0.05) in the sensory characteristics of the samples in which Sanyakbyung with 10% glutinous rice flour was most preferred in color, those with 20% in flavor, and those with 40% in taste. Adhesiveness and consistency in the palate responses also showed significant differences among samples in which the sample with 40% glutinous rice flour was most favored in consistency. When the content of yam increased, the gumminess also increased. Generally, Sanyakbyung with soft but less gummy texture was preferred to strong gummy one which was easily stuck to teeth. In the overall acceptance, Sanyakbyung with 40% glutinous rice four was most preferred.

• Food Science and Preservation
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• v.16 no.5
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• pp.680-685
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• 2009

We assessed the quality characteristics of instant Nuroong-gi prepared with 0%, 2%, 4%, 6%, or 8% (all w/w) yam powder. We measured color, water binding capacity, viscosity, the sedimented volume of insoluble solids, turbidity, total sugar, and reducing sugar and conducted sensory evaluation. Lightness decreased with a rise in the proportion of yam powder. However, both redness and yellowness rose with an increasing proportion of powder. The water binding capacities of Nuroong-gi prepared with yam powder were higher than that of rice powder. The viscosity increased with increasing levels of powder. The level of insoluble solids, the turbidity, and the concentrations of total sugar and reducing sugar all rose with increasing cooking temperature. Sensory evaluation showed that Nuroong-gi with yam powder at 2% (w/w) was optimally acceptable.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.461-466
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• 2009

This study was carried out to evaluate the effects of yam (Dioscorea batatas Dence) extracts on the cell viability, growth and nucleus-DNA damage of tobacco cells which were exposed to $\gamma$-radiation stress. The viability and growth of tobacco cells exposed to 20 Gy of radiation stress were effectively recovered by pretreatment of 10 mg/L ethylacetate (EtOAc) yam extract. Pretreatment of EtOAc extract showed 20% higher cell viability and fresh weight growth than that of cells without pretreatment in 20 Gy radiation treated tobacco cells. Nucleus-DNA damage was measured as the ratio of tail length (T) to head length (H) in individual comet image isolated from tobacco cells. The T/H ratio of control-cells and treated-cells at 20 Gy were 1.05 and 1.68, and % head DNA of those cell were 86.7 and 71.3%, respectively, suggesting that nuclei of tobacco cells were severely damaged in the integrity of DNA by the treatment of $\gamma$-radiation. However, pretreatment of MeOH, EtOAc and n-BuOH extracts decreased radiation induced DNA-damage in the tobacco cells, showing T/H ratio of 1.37, 1.01 and 1.10 and % head DNA of 81.5, 87.6 and 88.7%, respectively.