• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.425-430
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• 2011

This study evaluated the effect of extraction conditions of yam (Dioscorea aimadoimo) on antioxidant, moisturizing, collagenase activity, proliferation, and migration. Yam has been recognized as a healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-mutagenic activities, as well as its ability to decrease blood glucose and cholesterol levels. Electron donating ability of high temperature ethanol extract of Dioscorea aimadoimo (HDA) had shown 70.6% at 400 mg/ml, and low temperature ethanol extract of Dioscorea aimadoimo (LDA) had shown 40% at 400 mg/ml. SOD-like activities of LDA and HDA were 23% and 34% at 400 mg/ml respectively. LDA significantly reduced the activity of collagenase in a dose-dependent manner, which was higher than HDA. The water contents in LDA-treated skin and HDA-treated skin were increased by 45.63% and 38.65% than the placebo cream respectively. The cellular proliferation of human dermal fibroblast neonatal (HDFn) was evaluated by MTT and cell migration assay. Compared to control, the cell proliferation was elevated to 109.7% and 114% by the treatment of LDA and HDA respectively at the concentration of 200 mg/ml. In addition, LDA and HDA were induced cell migration in HDFn. Our study suggests that LDA and HDA should be a very useful cosmetic ingredient, as anti-aging and skin moisturizer.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.36-40
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• 1995

Yam(Dioscorea) tubers were used as one of the dietary starches in Korea, China and Japan because of its characteristic properties. Yam tubers were powdered after freeze drying the sliced tubers to investigate carbohydrates. Chemical properties such as proximate components and carbohydrates were studied using three varieties of Korean yams, namely. D. batatas, D. aimadoimo and D. japonica. The proximate components of yam tubers showed that the major components of Korean yam tubers were carbohydrates and moisture. The main components of free sugars in yams were identified as fructose, glucose, sucrose and maltose. In addition to these four sugars, there were two unidentifiable peaks whose areas are too big to ignore. These results were obviously different from other reported data of free sugars in yams. The main components of total sugars were mannose and glucose.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 1996.04a
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• pp.22.1-22
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• 1996

• Applied Biological Chemistry
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• v.37 no.6
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• pp.509-515
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• 1994

Using the lipids extracted from Korean yam(Dioscorea) tubers, D. batatas, D. aimadoimo and D. japonica, fractionation and identification of lipid components and their fatty acid compositions were analysed. Lipid contents determined by Folch's method in D. batatas, D. aimadoimo and D. japonica were 11.0 mg/g, 11.4 mg/g and 6.6 mg/g, respectively. Lipids extracted were fractionated into neutral lipid, glycolipid and phospholipid by silicic acid column chromatography. The content of neutral lipid was over about 60% in lipid. Neutral lipid was composed of sterol ester, triglyceride, 1,3-diglyceride, 1,2-diglyceride and monoglyceride. Main constituents of glycolipid were acylsterylglycoside, monogalactosyldiglyceride, sterylglycoside, digalactosyldiglyceride and sulfolipid, and phospholipid contained phosphatidylethanolamine, phosphatidylcholine and phosphatidylinositol. The fatty acids of the total lipid and its three lipid fractions were analyzed by GC. The major fatty acids were palmitic and linoleic acids. Content of the saturated fatty acids was less than that of the unsaturated fatty acids.

• The Korean Journal of Food And Nutrition
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• v.5 no.1
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• pp.49-54
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• 1992

In an attempt of develop composite flours, D. aimadoimo of yams in Korea was investigated with respect to its physicochemical properties and sensory analysis with baking bread. The results are summarized as follows ; 1. Yam had 73.21% of water, 21.65% of carbohydrate, 3.3% of crude protein, 0.25% of fat, 1.60% ash and 20.3%of starch. 2. Sucrose was 78% of the total free sugars in yam flour. It was contained which 67% of total free amino acids were serine, arginine & alanine and 23.6% of total amino acids was glutamic acid. 3. As the yam flour level in amylogram patterns (8% dry basis) was increased, the initial pasting temperature was increased and the viscosity decreased. 4. Replacement of yam flour with 10% wheat flour was the bests in sensory evaluation of the products.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.652-657
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• 1995

To investigate the lipid components of Korean yams(Dioscorea batatas and Dioscorea aimadoimo), silicic acid column, thin layer and gas chromatographies were applied. Total crude lipid contents in D. batatas and D. aimadoimo were 1.70% and 1.31%, and total purified lipid contents were 1.35% and 0.99% on a dry weight basis. Lipids were fractionated and quantitated by silicic acid column chromatography. The contents of neutral lipids, glycolipids and phospholipids were 43.33, 39.60 and 17.07% in D. batatas and 43.94, 34.74 and 21.32% in D. aimadoimo. Neutral lipids were the most abundant, in which triglycerides and sterol ester were found as the major components. Glycolipids were mainly composed of monogalactosyl and trigalactosyl diglycerides. Phosphatidyl choline and phosphatidyl ethanolamine were the major components of phospholipid. Fatty acids of the total lipids were mainly linoleic and palmitic acids. The fatty acid compositions of neutral lipids, glycolipids and phospholipids were the same tendency as that of total lipids. However, the content of linolenic acid in glycolipids was higher than in neutral lipids and phospholipids when fractionated.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.384-388
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• 1996

This research was conducted to investigate the effective methods for browning inhibition on yam (Dioscorea aimadeimo) during dehydration by physical and chemical pretreatments. Moisture, crude protein, crude fiber and N-free extract contents of yam were 81.17%, 1.43%, 0.29% and 15.81%, respectively. Yams were sliced to 0.5 cm thickness and placed to single and poly layer in plastic tray, and then changes of their weights were measured during air dehydration at $50^{\circ}C,\;65^{\circ}C,\;and\;80^{\circ}C$. The dehydration time reaching to optimum moisture level for the pulverization of the yam slices were 10, 6, 3 hours(single layered) and 12, 7, 5 hours(multi layered) at the respective temperature. To inhibit browning at $80^{\circ}C$ air dehydration, water and steam blanching, microwave treatment effects were investigated on yam slices for 30 sec. and 60 sec. Steam blanching for 30 sec. was comparatively effective to inhibit browning of yam slices. Yam slices were immersed in single and combined browning inhibitor solutions and evaluated for browing degree during dehydration by the values of Hunter L, a, b and ${\Delta}E$. The most effective pretreatment to inhibit browning of yam slices was immersion In the solution containing 500 ppm of citric acid and 1000 ppm of cysteine for 1 min.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.619-622
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• 1992

To increase utilization of Korean yam, the rheological properties of gelatinized yam (Dioscorea aimadoimo) starch solutions at various concentrations $(1{\sim}5%)$ and temperature $(30{\sim}60^{\circ}C)$ were investigated. The rheological behavior of gelatinized yam starch solutions was illustrated by power-law model and Casson equation and exhibited pseudoplastic behavior with yield stress. The pseudoplasticity of starch solutions increased largly concentration of starch increased. As the temperature increased from $30^{\circ}C$ to $60^{\circ}C$, the dependency of starch concentration decreased, B were decreased from 0.40449 to 0.39352. The activation energy of flow of gelatinized yam starch solutions were increased from 4.1415 to $5.45329{\times}10^6\;J/kg{\cdot}mol$ by increasing starch concentration from 1% to 5%.