• Korean Journal of Veterinary Research
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• v.29 no.1
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• pp.21-25
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• 1989

This experiment was carried out to determine the progesterone concentration of bovine plasma by liquid phase double antibody enzyme immunoassay. The optimum conditions of assay-system, enzyme conjugate and gelatin were invested. The sensitivity, recovery rate and reproducibility by this assay were also analyzed. The results obtained were as follows: 1. The suitable supplementation level of gelatin was 0.2%. As the gelatin level increased to 1%, coefficient variation of interassay was shown to be irregular. 2. The optimum dilution rate of enzyme conjugate was 30 times. Enzyme activity was greatly fluctuated depending on the minor condition of enzyme conjugate technique. Therefore, it was considered to be checked when determined. 3. The sensitivity of the assay was 12 pg/tube. 4. Recovery rate was decreased when the amount of sample was too little or too much, but the recovery rate was high as 97.8% when the amount of sample between 50 and $200{\mu}l$. 5. Mean intra-assay and inter-assay coefficient of variation was 4.5% and 5.9%, respectively. By using liquid phase double antibody enzyme immunoassay, progesterone in plasma can be detected, and also this assay system is applicable to study on physiological function of progesterone and to diagnosis of reproductive disorders.

• Korean Journal of Human Ecology
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• v.23 no.3
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• pp.467-481
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• 2014

We investigated the effects of Mulberry leaves fermented enzyme liquid(MLE) addition on the quality of Kimchi which were fermented at $5^{\circ}C$ during 30 days. MLE was added to salted cabbage at concentrations of 0%(C), 0.4%(MLE1), 0.8%(MLE2), and 1.2%(MLE3) (w/w). pH in Kimchi added upon 1.2% of MLE, was higher than that of Kimchi without MLE after 12 days of fermentation. The titratable acidity was increased by the addition of MLE, and particularly Kimchi added 1.2% of MLE showed the slowest changed level. The degree of salinity were decreased in Kimchi with MLE as well as control group. However, MLE1 showed significantly lower salinity than MLE2, MLE3 and control group (p<0.001). L, a, b values of control group indicated significantly higher than the Kimchi with enzyme liquid concentrations(MLE1~MLE3). As compared with the control group, the cutting force in treated groups were increased during the fermentation period, and especially MLE3 showed the highest value of hardness. Moreover, that growth of lactic acid bacteria and total bacteria were inhibited by the addition of MLE. In the sensory assessment, the color, taste, and overall preferences were higher in MLE2 than control group and MLE1, MLE3. The acceptability of MLE as an additive in Kimchi among middle school students was higher than in the control sample, with an optimum additive of 0.8% MLE, based on the lowest volume of leftovers. Therefore, it was confirmed that addition of 0.8% MLE appears to be an acceptable approach to enhance the quality of Kimchi without reduction of acceptability.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.183-187
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• 1991

The effects of microwave heat treatment and addition of enzyme, kimchi liquid, buffer solution and several salts on the changes in pH of kimchi liquid were investigated during fermentation at $25{\sim}35^{\circ}C$. It was found that microwave heat treatment on brined chinese cabbage and enzyme addition of cellulase and amylase showed a little improvement effect, while combination of both methods significantly increased the fermentation rate. The addition of kimchi liquid having pH 4.6 was found to be very desirable for both shortening the fermentation time and flavor acceptance. Among the inorganic salts and buffer solution studied, phosphate buffer(pH 4.6), sodium nitrite and $Na_2HPO_4$ were significantly effective for reduction of kimchi fermentation rate by two to three folds.

• YAKHAK HOEJI
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• v.38 no.1
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• pp.12-19
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• 1994

Capsaicin(8-methyl-N-vanillyl-6-nonenamide) is the principal pungent component of Capsicum fruits. This work is directed to the capsaicin-hydrolyzing enzyme playing a key role in the rate limiting and critical step of capsaicin metabolism. In order to get precise information on the enzyme's subcellular location, rat liver homogenate was divided into six subcellular fractions by differential centrifugation technique: crude nuclear pellet, PNS(post nuclear supernatant) fraction, lysosomal pellet, cytosol, Tris wash fraction, micrisomes. Capsaicin-hydrolysing enzyme activity was analysed by high performance liquid chromatography(HPLC). This enzyme was found at the highest specific activity in the microsomal fraction and co-distributed with marker enzymes of the endoplasmic reticulum, NADPH-cytochrome c reductase and nucleoside diphosphatase. This is compatible with the result of ninhydrin color reaction of vanillylamine, primary metabolite of capsaicin hydrolysis, on thin layer chromatography(TLC). This enzyme is most active at pH $8.0{\sim}9.0$. Definite subcellular location of this enzyme will make it easy to proceed with further study.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.213-220
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• 1983

Conditions for isolation of protoplasts from conidiospores of Trichoderma koningii ATCC 26113 were tested. Maximum production of conidial protoplasts was obtained by preincubation of conidiospores on liquid minimal medium for 8 1/2 hrs. and by reaction with cell wall lytic enzyme for 3 hrs. Among effective cell wall lytic enzymes (Driselase, p-Glucuronidase, Novozyme and Zymolyase), Driselase was the most effective one on the production of conidial protoplasts. The production of conidial protoplasts was also enhanced by addition of 2-Deoxy-D-Glucose $(25{\mu}g/ml)$ into liquid minimal medium. Over 70% of the initial swollen conidia, preincubated in liquid minimal medium supplemented with 2-Deoxy-D-Glucose $(25{\mu}g/ml)$, were converted to protoplasts by incubation with 2% (w/v) commercial lytic enzyme Driselase at $28^{\circ}C$ for 3 hrs. The reversion frequency of the conidial protoplasts was about 30 times (25-50%) higher than that of mycelial protoplasts (0.6-1.3%).

• Mass Spectrometry Letters
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• v.5 no.2
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• pp.52-56
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• 2014

Glycated hemoglobin (HbA1c) is used as an index of mean glycemia over prolonged periods. This study describes an optimization of enzyme digestion conditions for quantification of non-glycated hemoglobin (HbA0) and HbA1c as diagnostic markers of diabetes mellitus. Both HbA0 and HbA1c were quantitatively determined followed by enzyme digestion using isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with synthesized N-terminal hexapeptides as standards and synthesized isotope labeled hexapeptides as internal standards. Prior to quantification, each peptide was additionally quantified by amino acid composition analysis using ID-LC-MS/MS via acid hydrolysis. Each parameter was considered strictly as a means to improve digestion efficiency and repeatability. Digestion of hemoglobin was optimized when using 100 mM ammonium acetate (pH 4.2) and a Glu-C-to-HbA1c ratio of 1:50 at $37^{\circ}C$ for 20 h. Quantification was satisfactorily reproducible with a 2.6% relative standard deviation. These conditions were recommended for a primary reference method of HbA1c quantification and for the certification of HbA1c reference material.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.377-382
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• 1991

Reef tallow was hydrolyzed with lipase under the conditions of liquid state and solid state. Lipase OF 360 was used for that purpose, and the lipase had the maximum activity when the olive oil was used as a substrate at pH 6 and $37^{\circ}C$. Beef tallow was dispersed by an agitator to perform a liquid enzymatic reaction. Water content, reaction temperature, and enzyme amount were varied as parameters affecting hydrolysis percentage. Ninety three percents of tallow were hydrolyzed at the following conditions: water content 80% w/w, temperature $37^{\circ}C$, and enzyme amount 200 unitlg tallow. In order to conduct a solid phase enzymatic reaction, sonication was employed for pretreating tallow with the enzyme solution. Molten tallow was sonified with the enzyme solution, and solidified by lowering temperature. And then hydrolysis reaction proceeded at $30^{\circ}C$. Sonication intensity and time were varied to control hydrolysis percentage. Optimum values of the intensity and the time were found to exist since the hydrolysis percentage did not increase further according to the increases of the intensity and the time.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.3149-3151
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• 2011

• Applied Biological Chemistry
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• v.41 no.4
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• pp.270-272
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• 1998

Angiotensin converting enzyme (ACE) inhibitor was isolated from beef bone extract hydrolysate. After hydrolysis of beef bone extract with a commercial protease, ACE inhibitory peptide was purified by using ultrafiltration, gel permeation chromatography, and reverse-phase high pressure liquid chromatography. The purified ACE inhibitor was a pentapeptide, Gly-Pro-X-Gly-Pro.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.51-56
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• 1998

A bacteium, KP-6408, capable of hydrolyzing fibrin was isolated from Chungkook-jang, which was possibly identified as a strain of Bacillus sp. The effects of culture condition and medium composition on the enzyme production were investigated. Among nitrogen sources tested, yeast extract was the most effective for the enzyme production, and the level of the concentration for the optimal enzyme production was 0.2%(w/v). For carbon sources, glucose was the best for the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the organism at the liquid medium of the initial pH 8.0 and temperature of 4$0^{\circ}C$. In Chungkook-jang fermentation, the enzyme was maximally produced when incubated at 35$^{\circ}C$ for 24 hrs using soybean as a solid medium. The addition of various rice starch to the soybean in Chungkook-jang fermentation lowered the enzyme production.