• Culinary science and hospitality research
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• v.13 no.2
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• pp.254-259
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• 2007

The control of enzymic browning in potato slices by the use of citrate and phosphate buffer at different pH values and concentration was investigated. Minimally processed potatoes were stored at $5^{\circ}C$ and $20^{\circ}C$ followed by dipping in distilled water, citrate buffer (pH $3.0{\sim}5.0$) and phosphate buffer (pH $5.0{\sim}7.0$). The color characteristic was measured after storage at $5^{\circ}C$ and $20^{\circ}C$ for 24 hours. Treatment effectiveness was greatly improved by reducing pH and temperature. The citrate buffer was more effective than phosphate buffer in the browning inhibitory capacity. The citrate buffer (pH 3.0) showed the most anti-browning effect in this condition and more effective inhibition of browning by increasing concentration of treatment solution. The phosphate buffer (pH 5.0) treatment showed more effectiveness than concentration of 0.5 M of citrate buffer treatment.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.70-74
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• 2016

In this study, the effects of citrate buffer pretreatment conditions (solid-to-liquid ratio, reaction temperature, pH and concentration of buffer) on enzymatic hydrolysis of E. intestinalis for total reducing sugar (TRS) production were investigated. As a results of the citrate buffer pretreatment, a 5.40% hydrolysis yield was obtained under conditions including 1:10 solid-to-liquid ratio, 0.25 M citrate buffer (pH 3.5) at $140^{\circ}C$ for 60 min. The maximum hydrolysis yield of 18.68% was obtained to enzymatic hydrolysis after pretreatment. This result is 1.81 times higher than that of control.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.169-175
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• 2006

Potentiometric biosensor using flow injection analysis system was developed to determine citrate concentration in foods. Biosensor system consisted of sample injector, peristaltic pump, enzyme reactor, carbonate ion selective solid-state electrode, reference electrode, detector, and recorder. Enzyme reactor was prepared with immobilized citrate lyase and oxaloacetate decarboxylase. Carbonate ions produced through enzyme reactions of citrate were potentiometrically detected by ion selective electrode. Optimum conditions for biosensor system were investigated. Interference effect of major sugars and organic acids was less than 5% on citrate biosensor system. Citrate concentrations in fruit juices were determined by biosensor and gas chromatography. No significant difference was observed between two analytical methods. Results indicate citrate biosensor is useful in determining citrate concentration in foods.

• The Korean Journal of Zoology
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• v.25 no.3
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• pp.115-122
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• 1982

Plasma albumin was purified from the fresh bovine blood using a minor modification of the polyethyleneglycol and ethanol procedure. The resulting protein solution was tested for its purity by both electrophoretic and immunochemical methods and found to contain only the albumin molecules. Each of the four thiol reagents, maleate, iodoacetate, iodoacetamide and glutathione, was incubated with the purified plasma albumin. The electrophoresis on cellulose acetate of those complexes in various buffers with different component and pH demonstrated that the albumin-glutathione complex was separated into two zones in all buffers used except the barbital and sodium acetate buffers, that the complexes of albumin-iodoacetate and albumin-iosoacetamide also into two zones only in pH 4.8 citrate buffer and in pH 4.8 succinate buffer and that the new zone had more positive net charge compared to the native protein in any case. These results might suggest a possibility that the electrophoretic albumin fraction is composed of at least two molecular species with different conformation.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.105.2-105.2
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• 2010

전처리 후 얻어진 셀룰로스 고분자를 단당류로 전환하기 위해서는 셀룰라제를 이용한 당화 과정이 필요하다. 통상 실험식 연구에서는 셀룰로스 당화시 당수율을 최대로 하기위해 pH조절을 위한 Citrate buffer와 미생물 오염을 막기 위한 Autoclave에서의 멸균 과정을 거친다. 하지만 대량생산을 목적으로 하는 산업체에서는 적용이 어렵다는 문제점이 있다. 따라서 본 연구에서 이를 대신하여 산업체에서 적용 가능한 당화전환 공정의 효율성을 평가하고자 하였다. Autoclave 멸균을 대체하는 공정으로 항생제 첨가와 여과에 의한 제균을 선택하였고, citrate buffer를 대신하여 buffer를 첨가하지 않은 물을 pH를 조정하여 사용 하였다.실험결과 기존의 당화공정을 사용하였을 때 당화율이 81%이었고, pH를 조절한 제균 water에 항생제를 첨가하는 공정은 71%로 나머지 배지들 중 가장 높은 당화율을 나타냈다. 이것은 기존의 당화율보다 10% 낮은 수치이나 공정비를 교려하여 봤을 때 효율성 있는 공정으로 판단된다.

• Mycobiology
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• v.47 no.4
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• pp.483-493
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• 2019

Antrodia cinnamomea is a unique medicinal fungus in Taiwan. It has been found rich in some pharmacologically active compounds for anti-cancer, hangover, and immune regulation etc. With the in-depth study of these components, it would be interesting and important to establish a molecular system for basic studies of A. cinnamomea. Thus, we would like to set up a foundation for this purpose by studying the A. cinnamomea protoplast preparation and regeneration. Firstly, we studied the optimization method of protoplast preparation of A. cinnamomea, and found various factors that may affect the yield during protoplast preparation, such as mycelial ages, pH values, and osmotic stabilizers. Secondly, in the regeneration of protoplasts, we explored the effects of various conditions on the regeneration of protoplasts, including different media and osmotic pressure. In addition, we found that citrate buffer with pH value around 3 dramatically increased the regeneration of protoplasts of A. cinnamomea, and provided a set of regeneration methodology for A. cinnamomea.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.214-216
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• 1995

Passive films formed on chromium surface in citrate buffer solution were investigated by means of three-parameter ellipsometry. The citrate buffer was found to be a suitable medium in which oxide film on chromium could be removed by cathodic treatment, providing a reference surface for the optical study. The passive film effectively protecting the chromium surface from corrosion was found to have thicknesses in the range 0.65 to 1.25 nm depending on the potential in the range of -0.20 to 0.60 V (0.1M KCl calomel electrode). The complex refractive index of the passive film did not show significant potential-dependent changes, indicating that the composition of the film material does not depend on potential.

• Journal of Life Science
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• v.20 no.7
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• pp.999-1004
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• 2010

Investigations were carried out on a $\beta$-glucosidase produced by Aspergillus niger under solid-state fermentation conditions as a model of enzyme recovery from fermented wheat bran. The leaching efficiency of distilled water to recover the enzyme from the fermented bran was higher than acetate buffer, citrate buffer, citrate-phosphate buffer and 5% methanol; thus, the conditions were further optimized with distilled water as the extracting agent. After fermented bran was washed three times with distilled water for 1.5 hr each under shaking conditions at 1:5 solid to solvent ratio, a maximum recovery of 0.025 U/g of wheat bran was obtained.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.405-410
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• 1998

Boar semen extender Kp (Hankook Life-Science, Korea) was newly formulated by authors. This study was carried out to investigate the optimal concentrations of EDTA, Tris and citrate buffers in the Kp extender (Basic Kp) on the pH change during storage. And then the motility of boar sperm with the Kp pH stabilized (Modified Kp) was compared with those of commercial products imported into Korea such as BTS (Mini-tube. Germany; BTSg), BTS (Tri-bio, USA; BTSa) and Modena (SGI, USA). The pH values of all extenders were increased gradually with the storage days. Especially, the initial pH of Basic Kp was higher than that of BTSg, BTSa and Modena, and also higher than physiological pH of boar sperm (6.8∼7.5). When Basic Kp was added with various concentrations of EDTA (0, 0.63, 1.25 ＆ 2.37g/L), Tris (0, 0.18, 0.35, 0.71 ＆ 1.42g/L) and Citrate (0, 0.75, 0.81, 1.00, 1.25 ＆ 1.50g/L) buffers for pH down-regulation and stabilization of pH, the group added with 1.25g EDTA, 1.42g Tris and 1.00g Citrate well maintained the neutral range of pH during storage (6.88 at day1 to 7.33 at day6 in Modified Kp), Especially, the concentrations of the buffers added in Modified Kp were lower, until 1/2∼1/4 ranges, than those in Modena and other extenders. The motility of frozen-thawed boar sperm diluted with Modified Kp was significantly higher than that of Basic Kp, BTSg, BTSa and Modena (87.0% vs. 55.0∼71.0% at day1; 13.3% vs. 0∼6.3% at day6), Conclusively, Modified Kp in this experiment was kept the favorable physiological conditions in spite of low concentrations of the buffers and motility of frozen-thawed boar sperm was obtained better than that of Basic Kp and other commercial products such as BTSg, BTSa and Modena.

• The Journal of the Korean dental association
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• v.20 no.7 s.158
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• pp.625-630
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• 1982

The author observed the behavior of inflammatory cells in the primary intension of incisional wound on the Albino rat palate. The superficial wounds (0.5mm depth) were made anteroposterior lineally by surgical knife. They were sacrified on 4, 8, 12, 16, 24, 48, 72 and 120 hr after wounding. The specimens were fixed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer and 1% osmic acid in 0.1M cacodylate buffer, and embeddd in Epon 812. Ultrathin sections were obtained by LKB 8800, and stained with uranyl acetate/lead citrate, and observed with Corynth 500 EM.