• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.429-433
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• 2003

trans-Resveratrol(3,5,4'-trihydroxystilbene) is phenolic compound present in grapes, wines, and peanuts, has been reported to have health benefits including anticarcinogenic effects, protection against cardiovascular diseases and reduced cancer risk. A simple method for the quantitative extraction of trans-resveratrol from peanut has been developed. Optimal conditions for extraction were investigated. Type of solvent, time, and temperature assayed influenced trans-resveratrol yield. Adequate extraction condition was decided to ethanol/water (80:20v/v) maintained at $25^{\circ}C$ for 45 min. After extraction, the protocol consists of sample preparation using a $\textrm{C}_{18}$ solid-phase extraction (SPE) cartridge after concentrate with rotary evaporator and quantified by reversed phase HPLC using a $\textrm{C}_{18}$ column at 308 nm. Analytical methods for measuring trans-resveratrol in peanut were adapted to isolate, identify, and quantify trans-resveratrol in 11 peanut varieties by HPLC (high-performance liquid chromatography) with UV detector, The 11 peanut varieties content ranged from 0.018 to 1.125 $\mu\textrm{g}/\textrm{g}$ with an average of 0.289 $\mu\textrm{g}/\textrm{g}$. The contents were higher in the seeds with than without testa, regardless of varieties. The trans-resveratrol content was Higher in 110, 130 days after sowing than that of other period.

• Journal of Life Science
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• v.23 no.8
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• pp.1025-1031
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• 2013

From a 95% ethanolic extract of H. diffusa, four marker compounds (HD1~HD4) were isolated, which were relatively unique and exist in comparably high contents. The structures of marker compounds were identified as digitolutein (1), 2-hydroxy-3-methylanthraquinone (2), (E/Z)-6-O-p-coumaroyl scandoside methyl ester (4:1 mixture) (3), and (E/Z)-6-O-p-methoxycinnamoyl scandoside methyl ester (4:1 mixture) (4), respectively, on the basis of $^{13}C$ and $^1H$-NMR analyses. The calibration curves of marker compounds showed high linearity, as their correlation coefficient ($R^2$) were in the range of 0.9991~0.9999. In addition, the limit of detection (LOD) and the limit of quantification (LOQ) were $0.03{\sim}0.07{\mu}g/ml$ and $0.099{\sim}0.231{\mu}g/ml$, respectively. The intra-day/inter-day precision and accuracy were 0.23~2.00%/0.25~1.16% and 94.60~108.44%/94.73-110.23%, respectively. The optimal HPLC conditions for the simultaneous quantification of HD1~HD4 were as follows: stationary phase; Merck Chromolith RP-18e ($100{\times}4.6mm$, $5{\mu}m$), column temp.; room temperature, UV detection at 280 nm, flow rate; 2.0 ml/min, injection volume; $10{\mu}l$, mobile phase; start with the mixture of 80% solvent A ($H_2O$ containing 0.5% acetic acid) and 20% solvent B (methanol containing 0.5% acetic acid) and gradually decrease solvent A to 40% in 9 min., then retain this condition to 18 min. Under the HPLC condition, the four marker compounds 1~4 were successfully separated without any interference of other constituents. The results obtained in this study are expected to be helpful for the development of nutraceutics and natural medicines and for the quality control of this plant.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.686-691
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• 2012

The objective of this research is to present method development and validation for the simultaneous determination of lutein and zeaxanthin using ultra performance liquid chromatography (UPLC). Also, rapid quantification was performed on six green leafy vegetables (Allium tuberosum, Aster scaber, Hemerocallis fulva, Pimpinella brachycarpa, Sedum sarmentosum and Spinacia oleracea) that are commonly consumed in Korea. Separation and quantification were successfully achieved with a Waters Acquity BEH C18 ($50{\times}2.1mm$, $1.7{\mu}m$) column by 85% methanol within 5 min. Two compounds showed good linearity ($r^2$ > 0.9968) in $1-150{\mu}g/mL$. Limit of detection (LOD) and quantification (LOQ) for lutein and zeaxanthin were 1.7 and 5.1 g/mL and 2.1 and 6.3 g/mL, respectively. The RSD for intra- and inter-day precision of each compound was less than 10.69%. The recovery of each compound was in the range of 91.75-105.13%. Aster scaber and Spinacia oleracea contained significantly higher amounts of lutein ($4.06{\pm}0.24$ and $3.97{\pm}0.10mg$/100 g of fresh weight), respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.110-122
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• 1996

The n-3 family fatty acids containing ${\alpha}$-linolenic acid(18:3, ALA) have been known as physiological activation materials such as inhibitory effects on the incidence of hyper-tension, coronary heart disease and cancers as well as the control of senilc dementia. Although a lot of ALA(about $63\%$) are contained in perilla oil, it has not been commercialized yet because the purification technique of the ALA has not been well established. The procedure of purification of ALA from perilla oil was saponified with 1 N-KOH /ethanol and then saturated and low level unsaturated fatty acids were removed by low-temperature crystallization method. The concentrated unsaturated fatty acids (containing about $75\%$ ALA) went down through the silver nitrate-impregnated silica column chromatography for separation of high purity of ALA. The results obtained we Fraction B, C and D contained ALA more than $85.5\%$(recovery, >$88.9\%,\;95.4\%$(recovery, >$54.4\%$) and $99.9\%$(recovery, >$31.5\%$) in purity, respectively. Seed oil content of the tested varieties were ranged from 34.8 to $54.1\%$ with $45.3\%$ of varietal means. The major omega fatty acids contained in the oil were oleic acid(n-9) $15.2\%$, linoleic acid(n-6) $13.9\%$ and linolenic acid(n-3) $63.1\%$ in the mean value. Varietal variation of n-9, 6 and 3 fatty acids ranged of $9.5\~21.4\%,\;9.1\~20.4\%$ and $50.6\~70.5\%$ respectively. Unsaturated fatty acid were averaged $92.2\%$ of seed oil in fatty acid composition. The ratios of n-6 to n-3 ranged of $0.13\~0.34\%$($0.22\%$ in mean value). The highest n-3 fatty acid variety was Yecheonjong being $70.5\%$. The lowest variety in ratios of n-6 to n-3 was Goseongjong being $0.13\%$. Oil content showed positive correlation with stearic acid and linolenic acid, while the negative correlation with oil content and linoleic acid. On the other hand, A significant negative correlation were showed between linolnic acid and the ratios n-6/n-3 fatty acid, saturated fatty acid. Saturated fatty acid was highly correlated with unsaturated fatty acid negatively being $r= -0.723^{**}$.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.453-459
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• 2006

D-tryptophan and N-CBZ-D-phenylalanine were separated using ionic liquid as additives for the mobile phase in high performance liquid chromatography (HPLC). The ionic liquid of 1-butyl-3- methylimidazolium tetrafluoroborate (${[BMIm]}^+{[BF_4]}^-$) was used. Mobile phases were 65％, 70％, and 80％ methanol in water with addition of different concentrations (0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, and 15.0 mmol/L) of the ionic liquid. The experiments were performed on stainless steel column, $3.9{\times}300mm$ i.d., packed with $15{\mu}m$ octadecyl-bonded silica gel at laboratory.The retention factor of D-tryptophan was not negligibly changed while that of N-CBZ-D-phenylalanine was decreased. The resolution between the two components were affected by the contents of methanol and ionic liquid in the mobile phase. With the small content of methanol and the high concentration of ionic liquid, the resolution was improved.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.418-423
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• 2017

An analytical method for the determination of dexamethasone (DM) in bovine milk samples was developed and validated using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Milk samples were extracted by the liquid-liquid extraction based on acetonitrile. The chromatographic separation was achieved on a reverse phase $C_{18}$ column with gradient elution using a mobile phase of 0.1% formic acid in 95% acetonitrile. The procedure was validated according to the Ministry of Food and Drug Safety guideline determining accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Mean recoveries of DM from spiked milk samples (25, 125, and 1,250 ng/mL) were 98.9-109.6%, and the relative standard deviation was between 1.7 and 4.4%. Linearity in concentration range of 12.5-1,250 ng/mL was obtained with the correlation coefficient ($r^2$) of 0.9997. LOD and LOQ for the investigated DM were 0.15 and 0.5 ng/mL depending on milk samples, respectively. This method was reliable, sensitive, economical and suitable for routine monitoring of DM residues in bovine milk.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.559-565
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• 2003

An analytical method the determination of benzo(a)pyrene (BaP) and its hydroxylated metabolites, 1-hydroxybenzo(a)pyrene (1-OHBaP), 3-hydroxybenzo(a)pyrene (3-OHBaP), benzo(a)pyrene-4,5-dihydrodiol (4,5-diolBaP) and benzo(a)pyrene-7,8-dihydrodiol (7,8-diolBaP), in rat urine and plasma has been developed by HPLC/FLD and GC/MS. The derivatization with alkyl iodide was employed to improve the resolution and the detection of two mono hydroxylated metabolites, 1-OHBaP and 3-OHBaP, in LC and GC. BaP and its four metabolites in spiked urine were successfully separated by gradient elution on reverse phase ODS $C_{18}$ column (4.6 mm I.D., 100 mm length, particle size 5 ㎛) using a binary mixture of MeOH/H₂O (85/15, v/v) as mobile phase after ethylation at 90 ℃ for 10 min. The extraction recoveries of BaP and its metabolites in spiked samples with liquid-liquid extraction, which was better than solid phase extraction, were in the range of 90.3- 101.6% in n-hexane for urine and 95.7-106.3% in acetone for plasma, respectively. The calibration curves has shown good linearity with the correlation coefficients (R²) varying from 0.992 to 1.000 for urine and from 0.996 to 1.000 for plasma, respectively. The detection limits of all analytes were obtained in the range of 0.01-0.1 ng/mL for urine and 0.1-0.4 ng/mL for plasma, respectively. The metabolites of BaP were excreted as mono hydroxy and dihydrodiol forms after intraperitoneal injection of 20 mg/kg of BaP to rats. The total amounts of BaP and four metabolites excreted in dosed rat urine were 3.79 ng over the 0-96 hr period from adminstration and the excretional recovery was less than 0.065% of the injection amounts of BaP. The proposed method was successfully applied to the determination of BaP and its hydroxylated metabolites in rat urine and plasma for the pharmacokinetic studies.

• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.111-122
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• 1996

S. chibaensis J-59 produced an extracellular xylanase in a CSL medium composed of 1.5% com steep liquor, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, and 0.15% glucose containing xylan. but it did not produce in the culture medium containing xylose. The production of enzyme reached to a maximum level (0.83 uints/ml) when bacteria were cultured in 2.5 l jar fermentor for 48hrs at $30^{\circ}C$ and pH 7.0. Furthermore, S. chibaensis J-59 produced an intracellular glucose isomerase in a medium containing xylan and/or xylose. Xylanase was purified 29-fold over the culture supernatants of S. chibaensis J-59 by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50, and gel filtration on Sephadex G-200. The purified enzyme is a monomeric enzyme with a native molecular mass of 25 kDa and a subunit molecular mass of 25 kDa. The purified enzyme requires $Mg^{2+}$ for activity, $Ca^{2+}$, $Co^{2+}$ is not an inhibitor but inhibit by $Fe^{3+}$, $Hg^{2+}$, and $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down birchwood xylan at random giving xylobiose, xylotriose and xylotetrose as the main end products.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.376-381
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• 2021

Red beet (Beta vulgaris L.) is a root vegetable and a popular functional food ingredient of dark red-purple appearance due largely to betacyanins, principally betanine (75-95%) and its isomer, isobetanine (15-45%). This study developed an analytical method for beet red in terms of betanine and isobetanine in processed food products labeled with beet red as a food additive. High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) was used with a C₁₈ column. Linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and uncertainty in measurement were calculated for method validation. Matrix-matched calibration was applied to the candy, ice cream, and cocoa product, respectively, and R² was ≥0.9998, showing a high level of linearity. The LOD and LOQ were 0.16 to 0.32 and 0.48 to 0.97 mg/L, respectively. As a result of repeated intra-day and interday experiments to validate the accuracy and precision of the analytical method, the recovery rates were 96.0-103.1% and 100.0-102.2%, respectively and the RSD% was 0.5-3.3% and 0.9-3.8%, respectively. Moreover, the measurement uncertainty was estimated to be 1.71-12.43% depending on the matrix and the measured concentration. In this study, betanine and isobetanine were quantified (8.4-3,823.4 mg/kg) by applying the developed analytical method to processed food products (n= 26; e.g., candy, ice cream, and other processed foods) labeled with beet red as a food additive.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.334-339
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• 2019

A procedure based on high-performance liquid chromatography (HPLC) is described to determine ${\beta}-carotene$ in infant formulas. The method for ${\beta}-carotene$ analysis was performed on a C18 reversed-phase column using acetonitrile/methanol/dichloromethane (6:1:3, v/v/v) as a mobile phase. ${\beta}-Carotene$ was determined in HPLC with photo diode array (PDA) detector. The parameters of validation were specificity, linearity, LOD, LOQ, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity ($R^2$), which was over 0.999 in the range of 0.125~2 mg/L. The detection and quantification limits were 0.064 and 0.193 mg/L, respectively. The accuracy and precision of this method using an STD spiked sample were 80~119% and 1.02~2.05% respectively. The method was applied to the analysis of various infant formula and follow-up formulas products containing ${\beta}-carotene$, and all the products contained acceptable levels of ${\beta}-carotene$ for nutrition labeling.