Thermal Generation of Maillard Aromas - Recent Advances

Chi Tang Ho 한국응용생명화학회(구 한국농화학회) 1996 한국응용생명화학회 학술발표회 Vol.1996 No.1

민꽃게 및 꽃새우 효소가수분해물의 풍미발현성분

오광수(Kwang-Soo Oh),강수태(Su-Tae Kang),Chi-Tang Ho(Chi-Tang Ho) 한국식품영양과학회 2001 한국식품영양과학회지 Vol.30 No.5

인간의 기호에 바람직한 풍미를 지니고 있는 갑각류의 풍미발현성분을 살펴보기 위해 민꽃게와 꽃새우를 시료로 하여 효소가수분해물을 조제하고, 이들의 정미성분 및 자숙취 성분을 분석하였다. Body effect로서 맛 및 조직감에 영향을 미치는 것으로 알려져 있는 구성지방산의 조성은 민꽃게와 꽃새우 생시료의 경우 양자가 서로 비슷하여, 모두 16 : 0, 16 : 1n7, 18 : 0, 18 : 1n9, 20 : 5n3 및 22 : 6n3 등이 주요 구성지방산이었고, n3계열의 고도불포화지방산의 조성비도 각각 27.75% 및 28.46%로서 서로 비슷하였다. 민꽃게와 꽃새우 효소가 수분해물의 유리아미노산 총량은 각각 5,226.7 mg% 및 8,757.3 mg%이었고, 주요 유리아미노산은 양 시료 모두 taurine, asparagine, glutamic acid, glycine, alanine, isoleucine, leucine, phenylalanine, lysine 및 arginine의 함량이 많았고, dipeptide인 anserine도 비교적 많이 함유되어 있었다. 대부분의 아미노산이 꽃새우 쪽에 많이 함유되어 있었으며, 특히 asparagine, glutamic acid 및 proline 등은 꽃새우 쪽에 2배 이상 함유되어 있었다. 그리고 수산무척추동물 엑스분의 상쾌한 맛의 주성분인 betaine 함량은 각각 850.0 mg% 및 755.9 mg%로 다량 함유되어 있었다. ATP관련물질 중 AMP의 함량이 약간 많았으나, 양시료 모두 정미발현에 큰 영향을 주지는 못할 정도였다. 무기이온성분으로는 양시료 모두 Na, K, P 및 Cl 이온이 양적으로 많았으며, 그외 Ca 이온도 비교적 많이 함유되어 있었다. 민꽃게 효소가수분해물의 자숙취 성분은 acid류 6종, alcohol류 10종, aldehyde류 7종, ketone류 11종, ester류 1종, phenol류 5종, benzene류 4종, hydrocarbon류 22종, furan류 1종, 함질소화합물 21종 및 기타 11종으로 구성되어 있었고, 계수적인 측면에서 가장 많은 종류의 화합물은 alkane류를 위주로 한 hydrocarbon류 및 pyrazine류를 위주로 한 함질소성분이었다. 그리고 꽃새우 효소가수분해물의 자숙취 성분으로는 acid류 13종, alcohol류 10종, aldehyde류 6종, ketone류 10종, ester류 3종, phenol류 2종, benzene류 5종, hydrocarbon류 36종, furan류 1종, 함질소화합물 14종 및 기타 8종이 동정되었다. For the developing natural fisheries flavoring substances using crustacea, the flavor constituents of enzyme hydrolysates from shore swimming crab (crab) and spotted shrimp (shrimp) were investigated. In taste-active compounds of both enzyme hydrolysates, total free amino acid contents of crab and shrimp enzyme hydrolysates were 5,226.7 mg% and 8,757.3 mg%, respectively. The major amino acids were taurine, glutamic acid, proline, asparagine, glycine, alanine, valine, leucine, lysine, anserine and arginine. As for ATP related compounds, AMP was the principal component and small amounts of IMP was detected in both enzyme hydrolysates. In the quarternary ammonium bases, betaine was the principal component (593.8 mg%), and contents of TMAO and betaine in both samples were 60.7 mg% and 850.0 mg%, 124.1 mg% and 755.9 mg%, respectively. The major components were Na, K, P and Cl in inorganic ions. The major fatty acids of both sample were 14 : 0, 16 : 0, 16 : 1n7, 18 : 1n9, 20 : 5n3 and 22 : 6n3, and composition ratio of n3 polyunsaturated fatty acids of were 27.8% and 28.5%, respectively. Total 99~109 volatile compounds were detected as a cooked odor of crab and shrimp enzyme hydrolysates by SDE apparatus/gas chromatography/mass spectrometry. The volatile flavor compounds identified from cooked crab enzyme hydrolysate were composed of 6 acids, 10 alcohols, 7 aldehydes, 11 ketones, 1 ester, 5 phenols, 4 benzenes, 22 hydrocarbons, 1 furan, 21 nitrogen containing compounds and 11 micellaneous compounds. And the volatile flavor compounds identified from cooked shrimp enzyme hydrolysate were composed of 13 acids, 10 alcohols, 6 aldehydes, 10 ketones, 3 esters, 2 phenols, 5 benzenes, 36 hydrocarbons, 1 furan, 14 nitrogen containing compounds and 8 micellaneous compounds.

Effect of Low Temperature Ge Seed Layer and Post Thermal Annealing on Quality of Ge1-xSix (0.05 ≤ x ≤ 0.1) Graded Buffer Layers by UHV-CVD

Chi-Lang Nguyen,Nguyen Hong Quan,Binh Tinh Tran,Yung-Hsuan Su,Shih-Hsuan Tang,Guang-Li Luo,Edward Yi Chang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4

High crystal quality, smooth surface and fully relaxed Ge1-xSix (0.05 ≤ x ≤ 0.1) buffers are grown on 6°-off (100) Si substrate by UHV-CVD. A low-temperature (LT) Ge seed layer is used to improve the quality of the Ge1-xSix buffers. In this study, the LT-Ge seed layer is deposited directly onto the Si substrate at a low temperature of 315°C. After that, stress-free Si0.1Ge0.9 and Si0.05Ge0.95 layers are grown, respectively. An in-situ annealing process is also performed for the Si0.1Ge0.9/LT-Ge layers to increase the degree of relaxation. The total thickness of the epitaxial layer is 270 nm, with the average surface roughness at 0.6 nm.

Glutathione-S-Transferase Polymorphisms (GSTM1, GSTT1 and GSTP1) and Acute Leukemia Risk in Asians: a Meta-analysis

Tang, Zhen-Hai,Zhang, Chi,Cheng, Pan,Sun, Hong-Min,Jin, Yu,Chen, Yuan-Jing,Huang, Fen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

The association between glutathione-S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and risk of acute leukemia in Asians remains controversial. This study was therefore designed to evaluate the precise association in 23 studies identified by a search of PubMed and several other databases, up to December 2013. Using random or fixed effects models odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Heterogeneity across studies was assessed, and funnel plots were constructed to test for publication bias. The meta-analysis showed positive associations between GST polymorphisms (GSTM1 and GSTT1 but not GSTP1) and acute leukemia risk [(OR=1.47, 95% CI 1.18-1.83); (OR=1.32, 95% CI 1.07-1.62); (OR=1.01, 95% CI 0.84-1.23), respectively] and heterogeneity between the studies. The results suggested that the GSTM1 null genotype and GSTT1null genotype, but not the GSTP1 polymorphism, might be a potential risk factors for acute leukemia. Further well-designed studies are needed to confirm our findings.

Effect of Argon Gas Pressure on Residual Stress, Microstructure Evolution and Electrical Resistivity of Beryllium Films

Bing-Chi Luo,Kai Li,Ji-Qiang Zhang,Jiang-Shan Luo,Wei-Dong Wu,Yong-Jian Tang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.4

The residual stress in beryllium films fabricated on K9 substrates by using magnetron sputtering deposition is measured by using a curvature method and is theoretically estimated by using the Nix and Clemens (NC) model. The experimental results indicate that the 1.3-μm-thick film is always in a tensile state for pressure variations in the range from 0.4 to 1.2 Pa. When the sputtering gas pressure is increased, the average stress increases at first, after which it decreases by a remarkable amount. The observed descending trend of the tensile stress when the sputtering gas pressure is beyond 0.6 Pa is mainly attributed to the grain size in the film being larger than that in the film when the pressure is below 0.6 Pa. The maximal residual stress of 552 MPa at a sputtering gas pressure of 0.6 Pa is close to the tensile strength (550 MPa) of the corresponding beryllium bulk material and is about 8 times smaller than that calculated by using the N-C model. In addition, the surface morphologies of the as-fabricated films reveal fibrous grains while the cross-sectional morphologies are characterized by a coarsening of columnar grains. The measured electric resistivity of each film strongly depends on its porosity and the sizes of its grains.

우렁쉥이 껍질 카로테노이드의 가열분해로 생성되는 휘발성 화합물의 특성

최병대,(Chi Tang Ho) 경상대학교 해양산업연구소 1998 해양산업연구소보 Vol.10 No.-

N/A

Outer automorphism groups of polygonal products of certain conjugacy separable groups

김관수,Chi Yu Tang 대한수학회 2008 대한수학회지 Vol.45 No.6

Grossman [7] showed that certain cyclically pinched 1-relator groups have residually finite outer automorphism groups. In this paper we prove that tree products of finitely generated free groups amalgamating maximal cyclic subgroups have residually finite outer automorphism groups. We also prove that polygonal products of finitely generated central subgroup separable groups amalgamating trivial intersecting central subgroups have residually finite outer automorphism groups. Grossman [7] showed that certain cyclically pinched 1-relator groups have residually finite outer automorphism groups. In this paper we prove that tree products of finitely generated free groups amalgamating maximal cyclic subgroups have residually finite outer automorphism groups. We also prove that polygonal products of finitely generated central subgroup separable groups amalgamating trivial intersecting central subgroups have residually finite outer automorphism groups.

우렁쉥이 껍질 칼로테노이드의 가열분해로 생성되는 휘발성 화합물의 특성

최병대,Chi Tang Ho ( Byeong D 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.6

As an investigation for utilization of ascidian tunic carotenoids as a food color additives, we attempted to collect the volatile thermal degradation compounds from ascidian tunic carotenoids. Oxygenate volatile compounds were extracted by simultaneous distillation and extraction/concentration apparatus and analyzed by gas chromatography and mass spectrometery. Total 63 compounds were identified and some of them were caused by thermal degradation. They included 1,3,5-trimethylbenzene, 3,5,5-trimethyl-3-cyclohexen-1-ol, 3,5,5-trimethyl-3-cyclohexen-1-one, 1,1,2,3-tetramethyl-2-cyclohexen-5-ol, 1,1,2,3-tetramethyl-2-cyclohexen-5-one, 2,3,4,4-tetramethyl-6-hydroxy-2-cyclohexene-1-one, 1,2,3,8-tetrahydro-3,3,6-trimethyl-1-naphtol, dihydroacetinidolide, β-ionone, 2-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1-tolylethene, 2,6-dimethyl-8-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1,3,5-octatriene-7-yne. Proposed mechanism of formation of some compounds as thermal degradation products of ascidian tunic carotenoids are provided.

녹차와 녹차 플리폐놀의 담배에 의해 유발되는 폐암발생 억제효과

Yong Xu,Chi Tang Ho,Chi Han,Fung Lung Chung 한국식품과학회 1997 국제녹차심포지엄 Vol.1997 No.1

Sintering YAG:Ce phosphor ceramic layers onto glass substrates by CO2 laser for WLED applications

Chiu I-Chi,Nien Yung-Tang,Chen Pui-Jung 한국물리학회 2023 Current Applied Physics Vol.50 No.-

Cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor layers were sintered onto glass using CO2 laser. The layer adhesion was found to depend on the spin coating thickness. The x-ray diffraction indicated the formation of YAG phase, with minor impurities of Y2SiO5 and Y4Al2O9. When the coating thickness was 65 μm, the laser beam reacted thoroughly with glass and YAG precursors, and a liquid phase was formed, producing a thin amorphous layer (~5 μm) on the surface grooves. However, when the thickness was increased to 170 μm, the laser beam could not penetrate to react entirely with YAG precursors, resulting in more raw residues and poor adhesion. The sintered YAG:Ce phosphor layers on glass were characterized via photoluminescence, presenting yellow emission with a thermal quench to 75% at 125 ◦C, which is comparable to that of the solid-state reacted YAG:Ce ceramics.