The characteristics of extracts and precipitates after extraction at different water temperature (25, 50, 75, 95oC), ethanol ratio (25, 50, 75, 100%), and extraction method (stir, soak, autoclave) of yam powder and raw yam were investigated. The total polyphenol content was the highest in the 50% ethanol extract of yam powder. The DPPH radical scavenging activity was the highest in the 75% ethanol extraction and the crude saponin content was the highest in the 95oC water extraction. Tyrosinase inhibitory activity was the highest in 95oC water extraction, low concentration of ethanol extraction, and autoclave extraction. The peak viscosity, trough, and final viscosity of the precipitates increased after ethanol extraction, whereas decreased after the 95oC water extraction and the autoclave, indicating the destruction of starch granules. This was confirmed by observing the starch granules broken using the SEM. The significance of this study was to investigate the possibility of the use of yam resources as a material, processing product development, skin beauty functional food and cosmetic material.

The physiochemical properties of dried yam (Dioscorea batatas) by freeze dryer, cold-air dryer or hot-air dryer were examined for chromaticity, water absorption index (WAI), water soluble index (WSI), rehydration, viscosity properties and pasting properties. Freeze dried yam was maintained higher degree of lightness and higher WAI and WSI than those of cold-air or hot air dried one. In the case of rehydration, freeze dried yam was restored within one hour. The viscosity properties of freeze dried yam were the highest viscosity in all shear rates. Freeze dried yam was milled by roll mill (RM), pin mill (PM) or jet mill (JM) to evaluate for particle size, starch damage, pasting property and microstructure. Particle size was JM < PM < RM as 13.85~112.50 μm. In the result of starch damage, it was the highest value as 8.83 in JM, was the lowest value as 7.47 in RM. In pasting property, JM had relatively low viscosity at all shear rates. In the Microstructure by measuring scanning electron microscope, JM particle surfaces were rough with high starch damage, and particle size was confirmed fine particles in JM.

The aim of this study was conducted to investigate the proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids in Korean yam (Dioscorea batatas DECNE.). Carbohydrate (68.1%) possessed the large single constituent of yam. Small amounts of crude protein (16.9%), crude ash (5.8%) and crude fat (2.0%) contents were found. Yam was found to be good sources of essential minerals such as K (1295.5 mg/100 g), Mg (115.3 mg/100 g), Na (99.0 mg/100 g) and Ca (56.5 mg/100 g) but Zn (0.3 mg/100 g) content was low. Relatively abundant vitamin B1 (11.5 mg/100g) could be observed while vitamin A, B3 and B6 were not found. The amino acid analysis revealed that the yam was superior with respect to glutamic acid (1770.6 mg%), lysine (1210.6 mg%) and urea (550.9 mg%). Essential amino acids were calculated to be 2954.5 mg%. The amino acid profiles showed that yam to be limiting in valine and leusine. Palmitic acid and linoleic acid were the most predominant fatty acids with the value of 31.5% and 41.5%, respectively. And the polyunsaturated fatty acids including linoleic acid and linolenic acid were present in a large quantities in yam. And it also contained higher amounts of unsaturated fatty acids compared saturated fatty acids.

The bioactive compound and antioxidant property of Korean yam (Dioscorea batatas DECNE.) were studied using in vitro methods. Yam available in Korea was analyzed for lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. 70% Methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v) were used to extract yam. Then the antioxidant activity evaluated through ferrous ion chelating activity, β-carotene bleaching method, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging activity. 70% Methanol extract showed the highest ferrous ion chelating activity and NO radical scavenging activity. And CM extract was the most effective in inhibition of linoleic acid peroxidation evaluated by β-carotene bleaching assay and lipid peroxidation inhibition assay. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

The objective of this study was to investigate the antioxidant activity of Korean yam (Dioscorea batatas DECNE.) by different extraction solvents including 70% methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high L* value and H° value, which were 81.64±2.59 and 83.36±0.15, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract (37.62±0.88 mg CAE/g), 70% ethanol extract (43.38±0.66 mg CAE/g) and CM extract (67.17±0.12 mg CAE/g), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

In Korea, yam with thermal treatment is widely used to produce tea and beverage, which appeals to all age groups. To better understand the antioxidative activity of thermal treatment yam (Dioscorea batatas DECNE.), n-butanol and ethyl acetate extracts were evaluated with different antioxidant testing system. Their antioxidant activities, including ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were assessed in vitro. Results showed ethyl acetate extract (51.63±2.51 mg CAE/g) possessed similar total phenol content compared with n-butanol extract (53.93±1.00 mg CAE/g). Ethyl acetate extract also exhibited similarly stronger antioxidant activity compared with n-butanol extract apart from ABTS radical scavenging activity assay.

This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas DECNE.) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Results showed ethyl acetate extract (111.88±0.66 mg CAE/g) possessed higher total phenol content than n-butanol extract (78.68±0.58 mg CAE/g). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas DECNE.) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity β-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

In this study, n-butanol and ethyl acetate extracts were prepared from raw yam (Dioscorea batatas DECNE.). Their antioxidative potencies were investigated employing various in vitro methods, such as ferrous ion chelating, β-carotene bleaching assay, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging and nitrite scavenging activity. The n-butanol fraction was assayed to possess stronger antioxidant activity by β-carotene bleaching assay, lipid peroxidation inhibition and NO radical scavenging activity. However, ethyl acetate extract was more effective in chelating ferrous ion and scavenging nitrite. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

To better investigate the antioxidative property of thermal treatment yam (Dioscorea batatas DECNE.) in Korea, some established methods were used. 70% Methanol, 70% ethanol and chloroform–methanol (CM, 2:1, v/v) extracts were collected. 70% Methanol extract exhibited stronger antioxidative activity evaluated by ferrous ion chelating activity, NO radical scavenging activity and β-carotene bleaching assays. On the contrary, CM extract was the most effective in inhibiting linoleic acid peroxidation. Yam available in Korea was also analyzed for its bioactive compounds such as lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. Total saponin was abundant in thermal treatment, which determined to be 42.52±1.88 mg/g. Based on the results obtained from this study, thermal treatment yam could be used as natural antioxidant source due to its high antioxidant activity and bioactive compound contents.

The aim of this study was to investigate the antioxidant activity of thermal treatment yam (Dioscorea batatas DECNE.) in Korea. Thermal treatment yam was extracted by different solvents including 70% methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v). Then color property, total phenol content and antioxidant activity were analyzed. Yam possessed high L* value and H° value, which were 54.92±2.18 and 73.20±0.77, respectively. Thermal treatment yam exhibited great antioxidant activity evaluated by ABTS [2,2′ -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from thermal treatment yam increased in the following order: 70% methanol extract (63.53±0.33 mg CAE/g), 70% ethanol extract (69.47±1.00 mg CAE/g) and CM extract (97.49±0.66 mg CAE/g), respectively. The same trend was also could be found in antioxidant activity assays except for reducing power assay. These results implied that these extracts from thermal treatment yam might be useful to take a good part in prevention of human diseases and aging.

In this study, the thermal treatment yam (Dioscorea batatas DECNE.) was analyzed for its proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids. Thermal treatment yam is mainly consisted of carbohydrate (70.3%) with small amounts of crude protein (15.8%), crude ash (5.1%) and crude fat (1.6%). It was found to be a good source of essential minerals such as K (1100.2 mg/100 g), Mg (99.4 mg/100 g), Ca (54.8 mg/100 g) and Na (44.9 mg/100 g) but Zn (4.8 mg/100 g) and Fe (0.2 mg/100 g) content was low. Little amounts of vitamin E (8.3 mg/100 g), vitamin C (3.5 mg/100 g) and vitamin B1 (2.1 mg/100 g) could be found. The amino acid analysis revealed that the yam was superior with respect to serine (1454.2 mg%), lysine (684.6 mg%) and histidine (684.6 mg%). Essential amino acids were calculated to be 2849.3 mg%. The amino acid profiles showed that thermal treatment yam is limiting in isoleucine and phenylaline. Linoleic acid was the most predominant fatty acids with the value of 47.3% followed by palmitic acid (24.7%) and oleic acid (12.7%). And the unsaturated fatty acids including oleic acid and linoleic acid were present in big quantities in thermal treatment yam.

As a herbal supplement, Dioscorea batatas Decne (DBD) presents potent antioxidant activity and diverse health benefits. In the present study, functions of a 30 kDa glycoprotein isolated from DBD (hereafter, DBD glycoprotein) in the regulation of feed efficiency and fecal malodor in mice were explored. DBD glycoprotein produced protective effect against cytotoxicity induced by the ecotoxicological endocrine-disrupting substance bisphenol A in gastrointestinal epithelial HT-29 cells. To investigate its potential roles in the regulation of feed efficiency and fecal malodor, mice were administered an oral injection of DBD glycoprotein for 2 weeks. Compared with the control values, the weight of internal organs (liver, heart, kidney, and spleen) and levels of glutamate pyruvate transaminase, glutamate oxaloacetate transaminase, and lactic dehydrogenase were not significantly changed during DBD glycoprotein administration for 2 weeks. Interestingly, DBD glycoprotein improved feed efficiency and reduced hydrogen sulfide concentration without altering the ammonia level in mouse feces. Collectively, these results indicate that DBD glycoprotein is a functional agent that exerts gastrointestinal protective effects against ecotoxicological substances, improves feed efficiency, and reduces fecal malodor.

단마와 장마 영여자에 대한 항산화 및 항돌연변이원성을 비교 평가하였다. 단마와 장마 영여자 80% 메탄올의 폴리페놀함량은 2.2 와 3.9 mg/g로 장마에서 높았다. 또한 분획물에 있어서는 장마 영여자 에틸아세테이트 분획물에서 가장 높은 함량을 나타냈다. 그리고 DPPH과 ABTS 라디칼소거능 및 지질과산화 억제효과에 있어서는 총폴리페놀이 높은 장마와 에틸아세테이트 분획물에서 가장 높은 활성을 나타냈다. 한편 단마와 장마 영여자 80%메탄올 추출물 1mg/plate의 1-NP, AFB1, Trp-P-1에 대한 항돌연변이원성은 S. typhimurium TA98(hisD3052)에서 37.5, 24.5, 37.9% 돌연변이 억제효과를 나타내었으며, 장마 영여자는 31.7, 53.9, 56.85%의 돌연변이 억제효과를 나타냈다. 또한 분획물 중에는 단마와 장마 영여자 클로로포름과 에틸아세테이트 분획물에서만 돌연변이 억제효과를 나타내었으며, 농도 의존적으로 증가하였다.

식물세포에 마(Dioscorea batatas Dence) 추출액의 전처리가 방사선 스트레스에 노출된 배양세포의 활력, 생장 및 핵 DNA 손상에 미치는 영향을 조사하였다. 마의 분획추출물 중 EtOAc 분획추출물을 식물세포에 전처리하고 20 Gy의 방사선에 노출시키면, 마 추출물을 전처리하지 않고 방사선 20 Gy만 처리한 세포보다 세포의 활력과 생체중이 20%이상 증가하였다. Comet 분석에서 꼬리부분의 길이 (T)와 머리부분의 길이 (H)를 측정하여 T/H 비율을 조사하였다. 무처리 세포와 방사선 20 Gy를 처리한 세포의 T/H 비율은 각각 1.05 및 1.68로 나타났고, head DNA 량은 각각 86.7% 및 71.3%로 무처리 세포와 방사선을 처리한 세포간에는 큰 차이를 보여, 방사선에 의한 심각한 핵 DNA 손상을 관찰할 수 있었다. 그러나 마 추출물 중 MeOH, EtOAc 및 n-BuOH 분획추출물을 식물세포에 전처리하고 20 Gy 방사선을 처리하면, T/H 비율은 각각 1.37, 1.01 및 1.10이었고, head DNA량은 81.5%, 87.6% 및 88.7%로 방사선을 처리 하지 않은 무처리 세포 수준으로 회복되었다.

본 연구는 마의 지상부에서 형성되는 주아를 이용하여 이듬해 종서로 사용 가능한 씨마 생산을 위한 주아 재배법을 개발하기 위하여 수행하였으며, 파종기, 파종량, 파종주아 크기에 따른 씨마 수량을 검토하였다. 1. 주아 파종기가 늦어질수록 생장 일수가 짧아져 괴경장이 짧아지고 평균 괴경중이 가벼워지는 등 괴경의 크기가 작아졌다. 5월 11일 파종의 경우 씨마용으로 사용할 수 없는 무게가 20g 이하 되는 괴경수가 많아짐으로 파종은 늦어도 5월 1일까지 이루어져야 할 것으로 판단된다. 2. 파종량이 많을수록 괴경장이 짧아지고 평균 괴경중이 가벼워지는 등 괴경의 크기가 작아지므로 마로 사용 가능한 21~4kg 크기의 괴경수를 고려할 때 200kg/10a가 파종 적량으로 판단되었다. 3. 파종주아의 크기가 클수록 출아율과 평균 괴경중이 높아져 단위 면적당 괴경 수량이 높게 나타났다.

단마의 종근부위에 따른 수량성을 밝혀 적정 종근부위를 확인하고 새로운 지주설치 방법이 단마와 장마의 수량 및 생육에 미치는 영향을 구명하여 다수확 재배기술을 확립코자 수행한 실험의 결과를 요약하면 다음과 같다. 1. 출현기는 동부과 미부가 노두나 두부에 비하여 15일 정도 늦고, 출현율은 동부에서 다소 낮은 경향이였다. 2. 종근부위별 지상부의 생육은 두부가 가장 왕성하였고 지하부의 생육은 두부와 미부가 가장 왕성하였다. 3. 10a당 수량은 노두에 비하여 두부와 미부가 각각 16, 15% 증수를 보였으나 동부는 8%의 증수를 보였다. 4. 개화기와 영여자착생기는 모든지주설치 방법에서 비슷하였으나 지상부 생체중은 관행지주법에서 보다 네트를 이용한 Λ, I형 지주에서 높았다. 5. 단마는 지주형에 따라 큰 수량의 차이를 보이지 않았으나 장마는 Λ, I형 지주에서 각각 11.8%의 증수를 보였다. 6. 경영비를 고려할 때 네트지주형은 I형이 적합하였다.

마의 껍질을 제거하거나 상처가 생겼을 때 발생하는 갈변현상을 억제할 수 있는 방법을 개발코자 실험을 수행한 결과는 다음과 같다. 1. 마는 박피후 시간이 경과할수록 갈변지수가 높아지는 경향를 보여 박피 후 15시간에 갈변지수가 장마는 38까지 증가한 반면 단마는 13이 었으며 이로서 장마가 단마보다 갈변이 빠르게 진행됨을 알 수 있었다. 2. 장마의 경우 NaCl 2M 처리시 갈변억제율이 48시간에 48%로 가장 높았고 특히 80℃ 온탕처리의 경우 24시간까지 높은 억제율을 보였으나 이후 급격히 감소하는 경향을 보였다. 3. NaCl 1M 처리시 단마의 갈변은 43% 정도 억제 되었으나 NaCl 0.5M과 70℃ 온탕처리는 비슷한 억제현상을 보였다. 그러나 60℃ 온탕처리는 무처리보다 더 높은 갈변지수를 나타내었다.

본 연구는 한국산 마의 괴근 형태로 분류되는 장마와 단마를 개화기에 꽃의 방향 성분과 정유수율을 비교조사하여 향료로서의 기능성을 검토하기 위하여 실험을 수행하였던 바 얻어진 결과를 요약하면 아래와 같다. 1. 마꽃의 방향 성분은 총 26종이 확인되었으며 지방족 알콜류가 다량분포하여 향료 첨가물이나 향수의 기본재료로의 가능성이 있는 것으로 나타났다. 2. 단마는 장마보다 1,2-butyleneglycol은 11배, phenylalcohol은 12배, caproic acid는 28배, cis-3-methylsalicylate는 8배, cinnamic alcohol은 25배, α -hexyl cinnamic acid는 13배, laulic acid는 6배 높은 경향을 보였다. 3. 마꽃 방향 성분의 수율은 0.7%로서 그 이용 가능성이 크며 단마가 0.983%, 장마가 0.417%로 단마가 약 2.4배 수율이 높았다. 4. 마꽃의 방향 성분 조성과 정유성분 수율을 감안할 때 마의 부산물인 마꽃을 향료로서의 이용 가능성이 있다고 판단되었다.