• Food Science and Preservation
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• v.15 no.1
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• pp.49-57
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• 2008

This study was conducted to develop an optimal composite recipe for a cookie including yam powder that would be attractive to all age groups. Wheat flour was partially substituted by yam powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making cookies, respectively with each 5 level of yam powder $(X_1)$, Sugar$(X_2)$, butter$(X_3)$, by C.C.D (Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM (Response Surface Methodology). Sensory items showed very significant values in color, softness, overall quality (p<0.01), flavor (p<0.05) and those of instrumental analysis showed significant values in lightness, redness (p<0.05), spread ratio, hardness (p<0.01). Also sensory optimal ratio of yam cookie was calculated at yam powder 37.35 g, sugar 50.75 g, butter 78.40 g and it was revealed that the factors of influencing yam cookie aptitude were in older of yam powder, butter, sugar.

• Food Science and Preservation
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• v.19 no.6
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• pp.825-832
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• 2012

In this study, the quality characteristics and antioxidant activity of mulberry salad dressing prepared with yam juice during storage at $5^{\circ}C$ for four weeks were evaluated. The salad dressing was prepared with a salad base, mulberry, omija, and yam (4:4:6:1 or 4:4:6:3). Fresh yam juice was added to the salad dressing at 0, 7, and 18% levels. After four weeks storage, the pH increased whereas the acidity decreased. As the yam concentration increased, the pH increased to 3.84 and the acidity decreased to 0.14%. The Hunter color L (lightness), b (yellowness), and a (redness) values decreased over the storage period. After four weeks storage, the viscosity increased from 83.2 to 158.5 cp according to the amount of yam juice that was added. The antioxidant activity, such as the DPPH radical scavenging activity, and the total polyphenol content of the salad dressing improved as the yam concentration increased. Moreover, according to the storage time, the peroxide value did not increase. These results show that the mulberry salad dressing to which omija and fresh yam juice were added maintained its freshness with high antioxidative activity during storage.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.266-272
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• 2009

The annual productions of yam and its aerial bulbils are estimated to 5,000 and 2,500 ton, respectively. But the majority of bulbils had been discarded without specific use. In this study, methanol extract and its organic solvent fractions were prepared from bulbils of Dioscorea batatas Decne, and their antimicrobial, antithrombin, and antioxidant activities were evaluated, respectively. The methanol extract contained 58.98% of water-soluble materials as like yam's extract. But the bulbils's extract contained 12-folds of total polyphenol and 3.4-folds of total flavonoids compared than yam's extract, respectively. For antimicrobial activity the hexane and ethyl acetate fraction showed strong antibacterial activity at $500{\mu}g/disc$ concentration against gram-negative and gram-positive bacteria. Antifungal activity was not observed in any fractions. Strong antithrombin activity was found in the hexane fractions. At 4.8 mg/mL concentration thrombin time (TT) was over 300 sec, which is 4-folds extended than the TT of yam. In a while, the ethyl acetate fraction showed strong DPPH scavenging activity ($IC_{50}$ of $38.1{\mu}g/mL$), SOD-like activity and reducing power, which are comparable to vitamin C or BHT. Our results suggest that the bulbils of yam as yam tuber have useful bio-activities, such as antibacterial, antithrombosis, and antioxidant activity.

• Journal of Life Science
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• v.20 no.9
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• pp.1365-1372
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• 2010

We investigated the inhibitory effects of solvent extracts from dried yam on $H_2O_2$-induced oxidative stress and growth of cancer cell lines (HT1080 human fibrosarcoma and HT-29 human colon cancer cells). Yam (Dioscoreacea) has been recognized as a healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-proliferation, and anti-mutagenic activities, as well as its ability to decrease blood glucose and cholesterol levels. In order to determine the protective effect on $H_2O_2$-induced oxidative stress, DCFH-DA (dichlorodihydrofluorescin diacetate) assay was conducted. Acetone with methylene chloride (A+M) extract of dried yam appeared to reduce the levels of intracellular reactive oxygen species (ROS) with dose responses. Among the fractions, 85% aq. methanol fraction showed the highest protective effect on production of lipid peroxides. Inhibitory effects of A+M and methanol (MeOH) extracts on the growth of HT1080 and HT-29 cancer cells increased in a dose dependent manner. The treatments of n-hexane, 85% aq. methanol and n-butanol fractions (${\geqq}0.5$ mg/ml concentrations) significantly inhibited the growth of both cancer cells (p<0.05). From these results, 85% aq. methanol fraction showed inhibitory effects on cellular oxidation and growth of human cancer cells, suggesting that this fraction may contain active compounds of dried yam.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.56-68
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• 2014

Yam Yackwa (YP) was made by addition of yam power (15%) into flour. Depending on extension of storage time, lightness and redness of YP were increased. Yellowness of YP was decreasing until 3 days and increased from 9 days of storage. However, the yellowness of Yackwa without Yam powder (Non-YP) was increasing until 3 days and decreased from 6 days of storage. Hardness, gumminess, and chewiness of YP were improved compared to Non-YP. It means that the addition of yam power makes Yackwa soft. Oil absorption of Non-YP was low. Acid value and peroxide value of YP were 1.57 and 19.04, respectively. Moisture contents, crude ash, crude fat, crude protein, and carbohydrate of YP were $2.55{\pm}0.08%$, $0.71{\pm}0.01%$, $6.11{\pm}0.06%$, $15.97{\pm}1.40%$, and $64.66{\pm}0.09%$, respectively.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.53-59
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• 2014

This study was conducted to investigate the characteristics between non-fermented chinese yam and rice (non-FCYR) and fermented chinese yam and rice (FCYR). 1.1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, total polyphenol, flavonoid contents and reducing power were investigated to evaluate the anti-oxidation activities of FCYR. Also, productivity of monacolin K, major medicinal ingredient of FCYR, was investigated, using Aspergillus terreus KCCM 12225. In case of non-FCYR, DPPH radical scavenging activities for three kinds of yam (Dioscorea japonica, Dioscorea batatas, Dioscorea opposita) and rice were estimated about 51.8, 66.4, 42.2 and 7.5%, while in case of FCYR, those for three kinds of yam and rice were estimated to increased about 64.7, 74.7, 52.8, and 32.3%, respectively. Total polyphenol contents of non-FCYR were estimated to 196.9, 265.7, 160.1, and 91.6 mg/kg, while total polyphenol contents of FCYR were estimated to increase about 530.7, 708.3, 427.2, and 265.9 mg/kg, respectively. Total flavonoid contents of FCYR increased to 2.8-3.3 times higher than those of non-FCYR. Reducing power of non-FCYR was about 0.97, 1.28, 0.64, and 0.17 (OD at 700 nm), while, that of FCYR increased about 1.75, 2.38, 1.24, and 0.46. Remakable increase in monacolin K productivity of FCYR was observed. Monacolin K productivity of FCYR was estimated to 467.1, 514.8, 339.2, and 272.5 mg/kg, respectively. In this study, fermented chinese yam (Dioscorea batatas) was estimated to be effective biological activity material.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.281-285
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• 2003

For storage periods of tubers in Chinese yam, the levels of $\textrm{GA}_{44}$ and $\textrm{GA}_{20}$ was constant, meanwhile both $\textrm{GA}_{53}$ and $\textrm{GA}_{19}$ level were always higher than that of $\textrm{GA}_{44}$ and $\textrm{GA}_{20}$ㆍ $\textrm{GA}_9$ content as precursor of $\textrm{GA}_4$ was not changed during storage. $\textrm{GA}_{24}$ content was low to below 0.2 ng for 90 days after storage, $\textrm{GA}_{36}$ content as precursor of $\textrm{GA}_4$ like $\textrm{GA}_9$ was about 6-8 fold higher than that of $\textrm{GA}_9$ during storage. GA contents of the two gibberellin biosynthetic pathways were gradually increased when storage periods were progressed. Bioactive GA$_1$ content as the GA members of an early C-13 hydroxylation was always constant, and its content was very low as below 0.1ng per dry weight, meanwhile, bioactive $\textrm{GA}_4$ content as the GA members of non C-13 hydroxylation was drastically increased, also, its content was highest at 90 days after storage, and then decreased at 120 days after storage. Consequently, we suggest that $\textrm{GA}_4$ may be involved in controlling tuber sprouting in Chinese yam.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.68-72
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• 2003

The metabolism of [$^{14}\textrm{C}$] $\textrm{GA}_{12}$ in the Chinese yam (Dioscorea opposita Thunb. var. Tsukune) was examined to determine the identification of endogenous gibberellins. [$^{14}\textrm{C}$] $\textrm{GA}_{12}$ was metabolized to $\textrm{GA}_{53}$, $\textrm{GA}_{44}$, $\textrm{GA}_{19}$, $\textrm{GA}_{20}$, $\textrm{GA}_1$, $\textrm{GA}_8$, $\textrm{GA}_{15}$, $\textrm{GA}_{24}$, $\textrm{GA}_9$, $\textrm{GA}_{36}$ and $\textrm{GA}_4$. Radioactivity of GAs in non C-13 hydroxylation route was five-fold higher than that of early C-13 hydroxylation in analyzed GA-metabolites. Radioactivity of $\textrm{GA}_4$ was always four times higher than that of $\textrm{GA}_1$ at every feeding time. $\textrm{GA}_1$ radioactivity has always a lower level to below 200 DPM. The major pathway of endogenous GA metabolism in seedlings of the Chinese yam might be the non C-13 hydroxylation pathway.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.64.1-64.1
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• 2016

YAM (Young Astronomers Meeting, 젊은 천문학자들의 모임)과 We Love Galaxies는 인적/학문적 네트워크가 중요시되는 시대의 흐름에 발맞춰 국내 천문학 전공 대학원생들을 위한 워크샵인 "2016 YAM & We Love Galaxies 공동 워크샵"을 강촌에서 개최하였습니다. 2016년 2월 24일부터 26일까지 2박 3일간 개최된 이번 워크샵에는 총 35명의 대학원생/학부생/박사후연구원이 참가하였고, 전원 포스터 발표를 통해 참여 학생 모두가 자신의 연구주제를 자유롭게 소개하고 교류할 수 있도록 하였습니다. 뿐만 아니라 대학원 생활 및 연구 활동에 관련된 9개의 주제를 가지고 조별 토론을 진행하였습니다. 본 발표에서는 "2016 YAM & We Love Galaxies 공동 워크샵" 의 성과와 학생들로부터 받은 피드백을 소개하고 대학원생 워크샵이 나아가야 할 방향에 대해 제시하고자 합니다.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.554-560
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• 1991

The physicochemical properties of Korean yam starches (D. aimadoimo, D. batatas and D. japonica) were investigated. The mean granular size of starches were 23.5 μm for D. aimadoimo, 23.9 μm for D. batatas and 18.2 μm for D. japonica. Amylose content, blue value and water binding capacity was $29{\sim}33%,\;0.42{\sim}0.51%\;and\;109.9{\sim}118.3%$, respectively. The optical transmittance of 0.3% (dry basis) yam starch suspensions were increased at $70{\sim}75^{\circ}C$ and D. japonica showed typical two-step transmittance curve. The swelling power and solubility patterns increased over $60^{\circ}C$, and D. aimadoimo was the highest values. Amylogram patterns of 5% (dry basis) yam starch suspensions, determined by Brabender amylograph, were similar to that of yam flours and the viscosity of D. aimadoimo had 630 BU, which was about 5 times higher than 130 BU for D. batatas and D. japonica. Observation under scanning electron microscope lefted marks of resistance to glucoamylase because these surfaces were similar to the natural granules. In rates of solubiliazation by dimethyl sulfoxide, D. aimadoimo showed the highest value. (3-Amylolysis limits of yam starches and their amylose were $71.8%{\sim}75.5%\;and\;90.2{\sim}92.1%$, respectively. Gel filtration patterns of debranched amylopectin by pullulanase were divided into 3 peaks. The weight ratios of peak III to peak II in yam starches were $2.15%{\sim}2.42%$.