• KSBB Journal
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• 제18권1호
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• pp.70-73
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• 2003

TLC를 이용하여 시료에 있는 젖산을 간편하고 신속하게 분리하고 정량 분석 할 수 있는 조건을 개발하였다. Silicagel TLC plate를 사용하는 경우 전개용매로 Nitromethane : 1-Propanol $H_2O$를 2 : 5 : 1.5 (v/v/v)의 비율로 섞어 사용하고 발색시약으로 Bromocresol purple 을 50% 에탄올 100 mL에 녹여(pH 10) 준비한 Bromocresol purple reagent를 사용하였을 때, 젖산은 엷은 주홍색의 TLC plate의 바탕에 자은 노란색 spot으로 확인되었으며 이 조건으로 0.5 - 4% 농도 범위의 젖산을 포함한 시료를 희석 없이 99.4%의 신뢰도로 쉽게 정량 분석할 수 있었고, 개발한 조건의 유효성은 HPLC 와 lactate dehydrogenase를 이용한 젖산 정량 분석으로 확인되었다.

• 한국식품위생안전성학회지
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• 제25권4호
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• pp.294-302
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• 2010

연구에서는 식품 중에 bound-MCPD를 측정하기 위해 지방을 추출하고, 메탄올에 녹인 황산으로 $60^{\circ}C$, 4hr 가수분해하여 모두 3-MCPD로 전환시켜 분석등하는 실험법을 개발하였다. 기존의 논문과 비교하였을때 분석시간이 더 빠르고, 현재 식품공전에 등재된 3-MCPD 시험법에 접목시킨 시험법이다. 분석가능한 선형구간은 3-MCPD로서 10ppb(ug/kg)-2ppm(mg/kg), 이며 반복성이 상대표준편차 5%이내, 재현성의 상대표준편차는 선형구간에서 10%이내이다. 기기적인 LOD는 5.4ppb, LOQ 9.0ppb이며 회수율은 3-MCPD 85.53%, bound-MCPD 82.97%이다.

• 한국환경과학회지
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• 제9권1호
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• pp.75-80
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• 2000

Kinetic data for the acid phase anaerobic digestion were presented in this study and the constants were determined with acid production rate and gas production rate. Process models based on continuous culture theory were used to describe the characteristics of the acid forming microorganisms and to enable further development toward utilization of the process in a more rational manner. Acid phase digestion can be separated with appropriate manipulation of hydraulic retention time in anaerobic digestion. Kinetic analysis of data from the various hydraulic retention times using a phase specific model obtained form the acid phase indicated maximum specific growth rate of 0.40/h, saturation constant of 2,000mgCOD.$\ell$, yield coefficient of 0.35 mgVSS/msCOD utilized and decay constant of 0.04/h for the acid production rate. Similar analysis of data for the gas production rate indicated maximum specific growth rate of 0.003/h, saturation constant of 2,200mgCOD/$\ell$, yield coefficient of 0.035 mgVSS/mgCOD utilized and decay constant of 0.06/h.

• Near Infrared Analysis
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• 제1권2호
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• pp.21-27
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• 2000

Temperature-dependent changes in near-infrared (NIR) spectra have been measured for oleic acid, and nonanoic acid in the pure liquid state. Particular attention has been paid to the 5400-4800 cm$\^$-1/ region where a number of combination bands appear. The NIR spectra of oleic acid show that a band at 5303 cm$\^$-1/ increases with temperature while that at 5270 cm/sup-1/ decreases. It ha been found from their second derivative spectra that these spectral changes take place stepwisely with two break points at 30 and 53$\^{C}$, which correspond to the phase transition temperatures oleic acid reported previously. Principle component analysis (PCA) has been carried out for the NIR spectra of oleic acid in the 5400-4800 cm$\^$-1/ region measured over a temperature range of 15-80$\^{C}$. core plots of the first and second principal components (PCs) show that the NIR spectra are classified into three groups; the spectra measured in the temperature range of 15-30$\^{C}$, those in the range of 31-53$\^{C}$, and those in the range of 54-80$\^{C}$. These temperature ranges correspond to those for quasi-smectic liquid crystal, disordered liquid crystal, and isotropic liquid of oleic acid in the pure liquid state. In other words, PCA provides unambiguous evidence for the phase transitions. similar studies have been carried out for petroselinic acid and nonanoic acid in the pure liquid states, but they do not show any evidence for phase transitions.

• KSBB Journal
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• 제18권5호
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• pp.377-384
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• 2003

본 연구에서는 푸마르산 또는 숙신산을 생산/소비하는 생물공정에서 각 물질의 농도를 온라인 모니터링을 하기 위한 흐름주입분석기술 (FIA)을 개발하였다. 각 효소반응에 필요한 효소 (Fum/MDH, ICL/ICDH)를 VA-Epoxy Biosynth E3-carrier에 공유 결합에 의해 고정화하였고 소형 고정화 효소반응기를 흐름주입분석 장치에 도입하였다. 푸마르산-FIA 및 숙신산-FIA 시스템에서 고정화 효소 반응기의 특성 (예를 들면, 고정화 Fum/MDH 효소 반응기와 ICL/ICDH 효소 반응기는 최적 pH가 9.0이었으며 35$^{\circ}C$의 반응온도에서 최대 활성을 보임) 을 연구하였고 실제 생물공정에의 적용 가능성을 조사하기 위해 각 FIA 시스템의 성능을 조사하였다. 또한 모사공정과 실제 발효공정에서 푸마르산과 숙신산의 농도를 온라인 모니터링하여 오프라인 분석값과 비교하였고 잘 일치함을 볼 수 있었다.

• 한국수산과학회지
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• 제38권6호
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• pp.379-384
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• 2005

A high-performance liquid chromatography assay method for oxolinic acid in fish products was developed, evaluated and validated through the monitoring of oxolinic acid based on farming and distribution. The recovery rate of the developed method was $102.3-106.7\%$ as compared to conventional methods. The stock solution was stable for 3 weeks under refrigerated condition at $4^{\circ}C$ The performance limit was evaluated as 0.01ppm of oxolinic acid in fish muscle. 478 fish samples such as olive flounder, genuine porgy, common sea bass and black rock fish collected from fish farms in the coastal area from September 2001 to October 2004 were analyzed to evaluate overall efficiency of the modified method and to monitor the actual condition of oxolinic acid usage in fish farm. According to the monitoring results, the modified method was suitable for analysis of oxolinic acid in fish muscle and oxolinic acid might be used in a small portion of fish farms. The suggested analysis method of oxolinic acid was registered in the Korean Official Methods of Food Analysis and is being utilized for fishery products by the Korea Food and Drug Adminstration and the National Fisheries Products Quality Inspection Service.

• 분석과학
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• 제11권1호
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• pp.54-61
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• 1998

토천궁과 일천궁이 한방이나 가공시 기초 자료로 활용될 수 있도록 기본적인 화학 성분을 분석하였다. 일반성분은 토천궁이 조단백 함량이 높았으며, 무기질은 일천궁이 토천궁에 비해 칼륨과 나트륨이 높은 반면, 그외는 토천궁이 전체척으로 높았다. 유리당 조성은 sucrose만 검출되었고, fructose와 glucose는 검출되지 않았다. 지방산 조성은 linoleic acid, oleic acid, palmitic acid, linolenic acid 순으로 구성되었고, 토천궁과 일천궁의 주요 구성아미노산은 글루탐산, 아르기닌, 아스파르트산, 발린 순으로, 대부분 필수아미노산도 고루 분포되어 있었다.

• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.213-218
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• 2010

In a previous paper, we showed that 5-aminosalicyl-L-aspartic acid (5-ASA-Asp) has much greater deconjugation efficiency in the cecal contents than does 5-aminosalicyl-L-glutamic acid (5-ASA-Glu). To explore a reason for ineffective deconjugation of 5-ASA-Glu, structural analysis of the conjugate was performed. Aromatic acyl-L-glutamic acid derivatives, N-benzoyl-glumatic acid (BA-Glu), N-(2-hydroxybenzoyl)-glutamic acid (SA-Glu), N-(3-aminobenzoyl)-glutamic acid (3-ABA-Glu) and N-(4-aminobenzoyl)-glutamic acid (4-ABA-Glu), were prepared and incubated in the cecal contents. The deconjugation rates were compared with that of 5-ASA-Glu. The order of the rates was BA-Glu $\approx$ 4-ABA-Glu $\approx$ 3-ABA-Glu $\gg$ SA-Glu $\approx$ 5-ASA-Glu. The deconjugation of the aromatic acyl-L-glutamic acid derivatives was carried out by enzyme(s) in the cecal contents since the deconjugation did not occur in the autoclaved cecal contents and on incubation with N-benzoyl-D-glutamic acid. Our data suggest that the 2-hydroxyl group in 5-ASA is ascribed to the poor deconjugation of 5-ASA-Glu in the cecal contents.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.298-303
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• 2021

Comparative genomic analysis was performed on eight species of lactic acid bacteria (LAB)-Lactococcus (L.) lactis, Lactobacillus (Lb.) plantarum, Lb. casei, Lb. brevis, Leuconostoc (Leu.) mesenteroides, Lb. fermentum, Lb. buchneri, and Lb. curvatus-to assess their glutamic acid production pathways. Glutamic acid is important for umami taste in foods. The only genes for glutamic acid production identified in the eight LAB were for conversion from glutamine in L. lactis and Leu. mesenteroides, and from glucose via citrate in L. lactis. Thus, L. lactis was considered to be potentially the best of the species for glutamic acid production. By biochemical analyses, L. lactis HY7803 was selected for glutamic acid production from among 17 L. lactis strains. Strain HY7803 produced 83.16 pmol/μl glutamic acid from glucose, and exogenous supplementation of citrate increased this to 108.42 pmol/μl. Including glutamic acid, strain HY7803 produced more of 10 free amino acids than L. lactis reference strains IL1403 and ATCC 7962 in the presence of exogenous citrate. The differences in the amino acid profiles of the strains were illuminated by principal component analysis. Our results indicate that L. lactis HY7803 may be a good starter strain for glutamic acid production.

• 한국식품과학회지
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• 제4권3호
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• pp.213-223
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• 1972

This paper chose the methods of methylesterification of the use of methoxide, the mixture solution of methanol-benzen-sulfuric acid in transesterification of the fat in cow's milk and modified powder milk and separated by gas liquid chromatography with F.F.A.P., D.E.G.A. as liquid phase. Quantitative analysis of the fatty acid of milk fat in cow's milk and modified powder milk was determined by gas liquid chromatography using the method of temperature programming which should be used to obtain satisfactory separation of short chain fatty acid on the chromatogram. It was found that the fatty acid composition of cow's milk and modified powder milk are all the major fatty acid of milk fat obtained by GLC analysis. Main components was found to be from butyric acid to arachidonic acid showing Fig. 3, 4, 5 and Table 4, 5, 6, 7, 8, 9.