• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.570-577
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• 2000

A method was presented for determination of bisphenol F(BPF), bisphenol A(BPA), bisphenol F diglycidyl ether(BFDGE) and bisphenol A diglycidyl ether(BADGE) in 3 aqueous-based food simulants (water, 4% acetic acid, 20% ethanol) by reverse-phase high performance liquid chromatography(RP-HPLC)with fluorescence detection and gas chromatography with mass selective detection(GC/MSD). All the calibration lines in the range of $5{\sim}800\;{\mu}g/L$ had correlation coefficients greater than 0.9998 and detection limits of less than $1.2\;{\mu}g$ bisphenols/L. Precision at $200\;{\mu}g/L$ was under 3.1%. Recoveries of bisphenols simultaneously spiked to aqueous food simulants exceeded 95% for BPF and BPA but about 80% for BFDGE and BADGE. However, recoveris of BFDGE and BPADGE respectively spiked increased upto 95%. Detection limits in recovery test were less than $0.40\;{\mu}g$ bisphenols/L. In migration test bisphenols were determined by RP-HPLC coupled with confirmation by GC/MSD. Can coatings of epoxy phenol, modified epoxy, epoxy ester phenol and thermoset vinyl were exposed to the 3 aqueous food simulants. BPF, BFDGE and BADGE were not detected in all the can coatings but BPA was detected in 4% acetic acid and 20% ethanol in all the can coatings except modified epoxy.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1052-1056
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• 1997

When casein was hydrolyzed by trypsin, alcalase, neutrase, protamax, and S. aureus type V8, peptides $(100\;{\mu}g/mL)$ which were produced by trypsin and alcalase solubilized $6.42\;and\;2.37\;{\mu}g/mL)$ of added irons at pH 6, respectively, while peptides which were produced by other proteases solubilized less than $1\;{\mu}g/mL$. Peptides produced by trypsin and alcalase were fractionated to 10 fractions on a reverse phase column and each fraction was tested for its iron solubilizing ability at pH 6. Among peptides produced by trypsin, fraction 5 showed the highest iron solubilizing ability $(2.33\;{\mu}g/mL)$. In the case of alcalase, fraction 7 showed the highest iron solubilizing ability $(1.56\;{\mu}g/mL)$. To isolate iron binding peptides from peptides produced by trypsin and alcalase, immobilized iron affinity chromatography which irons were chelated to imino diacetic acids in chelating sepharose fast flow were utilized. Our results showed that immobilized iron affinity chromatography was an effective method to isolate iron binding peptides produced by either trypsin or alcalase from milk casein.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.30-35
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• 1999

A simple, rapid, efficient method is for extraction of 13 synthetic water-soluble food colours (Tartrazine, Amarnth, Indigo carmine, New coccine, Sunset yellow FCF, Allura red AC, Eosine, Fast Green FCF, Brilliant Blue FCF, Erythrosine, Acid red, phloxine, Rose Bengal) by polyamide resin and for their quantitative by high performance liquid chromatography (HPLC). Colours (coal-tar dyes) were extracted with polyamide resin and then determinated by HPLC. The HPLC conditions using a reverse phase partition type column $(Nova-pak\;C_{18})$, photodiode array (PDA) detector and 1% Ammonium acetate / 60% acetonitrile in water as eluent, were acceptable for various kinds of colorants. By the use of the proposed method, a survey of coal-tar dyes was carried out on 20 samples and that were detected $4.76{\sim}133.47\;ppm$.

• Herbal Formula Science
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• v.23 no.2
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• pp.199-208
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• 2015

Objectives : In the present study, we investigated the effects of ethanol extract of Scutellaria baicalensis (EESB) on the progression of cell cycle in human renal cell carcinoma Caki-1 cells. Methods : The effects of EESB on cell growth and apoptosis induction were evaluated by trypan blue dye exclusion assay and flow cytometry, respectively. The mRNA and protein levels were determined by Western blot analysis and reverse transcription-polymerase chain reaction, respectively. Results : It was found that EESB treatment on Caki-1 cells resulted in a dose-dependent inhibition of cell growth and induced apoptotic cell death as detected by Annexin V-FITC staining. The flow cytometric analysis indicated that EESB resulted in G2/M arrest in cell cycle progression which was associated with the down-regulation of cyclin A expression. Our results also revealed that treatment with EESB increased the mRNA and proteins expression of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), without any noticeable changes in cyclin B1, Cdk2 and Cdc2. In addition, the incubation of cells with EESB resulted in a significant increase in the binding of p21 and Cdk2 and Cdc2. These findings suggest that EESB-induced G2/M arrest and apoptosis in Caki-1 cells is mediated through the p53-mediated upregulation of Cdk inhibitor p21. Conclusions : Taken together, these findings suggest that EESB may be a potential chemotherapeutic agent and further studies will be needed to identify the biological active compounds that confer the anti-cancer activity of S. baicalensis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.155-161
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• 2002

Tetraselmis suecica (T. suecica) of Prasinophyta was selected because the growth rate is comparatively higher and the culturing is also easy. In order to investigate antioxidative activity, the soluble elements of T. suecica were fractionated using water and organic solvents such as methanol, hexane, chloroform, ethylacetate and butanol. The chloroform fraction of T. suecica showed strong antioxidative activity. The potential antioxidative activity was detected in hexane: ethylacetate (1:5) once used the fractions by different mixtures of organic solvents. This fraction was further purified by preparative thin layer chromatography (PTLC) and repeated reverse-phase HPLC. On the basis of chemical and spectroscopic evidences obtained by UV, FT-IR, FAB-MS and NMR, the compound purified from T. suecica was identified as pheophorbide-a. The antioxidative activity of the compound was comparable to that of $\alpha$-tocopherol and could be act as an antioxidant in foods.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.417-426
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• 1997

Rice bran protein hydrolysates were prepared and some of their physicochemical properties were investigated to utilize rice bran as starting material for functional food ingredient. Rice bran proteins (RBP) were prepared from defatted rice bran by alkaline extraction and isoelectric precipitation. The enzyme for hydrolysis of RBP was selected through measuring relative activity by pH-drop method and comparing the degree of hydrolysis (DH) of hydrolysates. The enzymatic hydrolysates prepared by $Esperase^{\circledR}$ treatment were partitioned into two fractions by ultrafiltration(UF) with a 10 kDa molecular weight cut-off membrane. Each fraction was applied to a cholic acid-conjugated ${\omega}-aminohexyl$ Sepharose 4B column and the bile acid-binding components were obtained by eluting with deoxycholate. Gel permeation chromatography on a Sephadex G-50 column revealed that molecular weight of the bile acid-binding fraction of UF permeate was distributed in ranges of $2\;kDa{\sim}10\;kDa$ and $0.2\;kDa{\sim}0.6\;kDa$. Three peaks (R-1, R-2 and R-3) were obtained by prep-HPLC of bile acid-binding fraction of UF retentate and analyzed for total and free amino acid composition. The results showed that proline content of the bile-acid binding polypeptides and peptides was four times as much as that of rice bran protein and that the peak corresponding to higher average hydrophobicity had a higher free amino acid content. Average hydrophobicity slightly increased with enzymatic hydrolysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.263-267
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• 1984

The present study was conducted to elucidate the triglyceride composition of walnut oil. The triglycerides were separated by thin layer chromatography (TLC) and fractionated on the basis of partition numbers by reverse phase high performance liquid chromatography (HPLC) on a column packed with $\mu$-bondapak $C_{18}$ using methanol-chloroform mixture as a solvent system. Each of these collected fractions was fractionated again on the basis of acyl carbon number of triglyceride by gas liquid chromatography (GLC). The fatty acid composition of triglycerides for each partition numbered group was also analyzed by GLC. From the results, it was found that walnut oil consists of ten kinds of triglycerides, and the patterns of major ones in walnut oil were as follows: 53.3% of $(C_{18:2},\;C_{18:2},\;C_{18:2})$, 10.1% of $(C_{18:1},\;C_{18:2},\;C_{18:2})$, 5.4% of $(C_{18:1},\;C_{18:1},\;C_{18:2})$, 4.3% of $(C_{18:1},\;C_{18:2},\;C_{18:3})$, 3.9% of $(C_{18:0},\;C_{18:2},\;C_{18:2})$, 2.0% of $(C_{18:0},\;C_{18:1},\;C_{18:2})$, 1.8% of $(C_{18:0},\;C_{18:2},\;C_{18:2})$.

• Food Science and Preservation
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• v.15 no.3
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• pp.437-444
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• 2008

Structured lipids(SLs) were synthesized by enzymatic interesterification with DHA-enriched fish oil(containing 27% docosahexaenoic acid) and soybean oil in the hatch-type reactor. The interesterification was performed for 24 hr at $55^{\circ}C$ and TLIM(immobilized lipase from Thermonyces lanuginosa, 10% by weight of total substrates) was mixed with 180 rpm of shaking. The fish oil and soybean oil were interesterifed with several weight ratio(fish oil : soybean oil, 2:8, 3:7, 4:6, 5:5, w:w), Reverse-phase high performance liquid chromatography with an evaporative light-scattering detector separated the triglyceride species of SLs. The products contained the newly synthesized peaks. Especially, one of peaks was distinctively increased with the increasing weight ratio from 2:8 to 5:5 while the peak of trilinolein (LLL) decreased vice versa. The effect of antioxidants such as catechin, BHT(Butylated hydroxytoluene), and their combinations on the oxidative stability in SL were investigated. Oxidative stability was carried out under oven test at $60^{\circ}C$ over 72 hr thereafter SLs were analyzed for total fatty acid content, rancimat, peroxide value, electronic nose and TBARS value. Among all combinations of antioxidant, the highest stability was obtained from 200 ppm of catechin. Besides, total tocopherol ($\alpha$, $\gamma$, and $\delta$-tocopherol), iodine and saponification value were analyzed in which iodine and saponification value of SLs were 151.19 and 182.35.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.70-81
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• 1989

Reverse phase liquid chromatographic elution behaviors of salicylic acid and its derivatives were studied with classical and modern high-performance liquid chromatography(HPLC) using Amberlite XAD-4 and XAD-7 resin packed columns. Capacity factors(k') were determined in the comparatively high concentration(from 0. 010F to 0. 150F) of ferric nitrate-50% methanol solution to elucidate the elution behaviors with classical method. On the other hand, k's were measured in the various concentrations of methanol and ferric nitrate(from $2.5{\times}10^{-4}F\;to\;1.0{\times}10^{-3}F$) solution of pH 2. 25 and 293K with HPLC to explain the elution mechanism of them, and to find their optimum separation condition. As a result, it was found that log k's of salicylic acid and its derivatives were decreased with increasing the concentration of ferric ion, and the decreasing slopes of the compounds on the increasing ferric ion concentrations were related with each stability constant of ferric salicylates. Some isomers of derivatives of salicylic acid could be separated in the optimum condition.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1635-1641
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• 1999

Bacillus subtilis PCA20-3 was isolated from meju and was found to produce a protease. The strain produced the maximum amount of enzyme in the medium containing soytone (0.2%), soluble starch (2%), $(NH_4)_2SO_4\;(0.1%),\;CaCl_2(0.1%),\;yeast\;extract\;(0.01%),\;K_2HPO_4\;(0.1%),\;and\;KH_2PO_4\;(0.1%)$. Protease was first concentrated by ammonium sulfate (80% saturation, w/v) precipitation of culture supernatant. Then the enzyme was purified by column chromatography using CM Sephadex C-50. The collected proteins were rechromatographed using Sephadex G-100 gel filtration column. The fraction with protease active from Sephadex G-100 gel chromatography was found to be pure when examined by SDS-polyacrylamide gel electrophoresis and YMC-pak reverse phase chromatography. Specific activity, yield and purity were 76 U/mg. 2.7%, and 7.6 fold, respectively. The molecular weight of the enzyme was estimated to be 31.5 kDa by SDS-PAGE. The number of amino acids calculated from molecular weight was evaluated about 321 residues. N-terminal sequence of the enzyme was $Val^1-Pro^2-Tyr^3-Gly^4-Val^5-Ser^6-Gln^7-Gly^8-Lys^9-Ala^{10}$.