• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.411-417
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• 2017

This study was conducted to establish the analysis method for the contents of choline in infant formulas and follow-up formulas by ion chromatograph (IC). To optimize the method, we compared several conditions for extraction, purification and instrumental measurement using spiked samples and certified reference material (CRM; NIST SRM 1849a) as test materials. IC method for choline was established using Ion Pac CG column and 18 mM $H_2SO_4$ mobile phase. The parameters of validation were specificity, linearity, LOD, LOQ, recovery, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity, $R_2$ was over 0.999 in range of 0.5~10 mg/L. The detection limit and quantification limit were 0.14, 0.43 mg/L. The accuracy and precision of this method using CRM were 95%, 2.1% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested products were acceptable contents of choline compared with component specification for nutrition labeling. The standard operating procedures were prepared for choline to provide experimental information and to strengthen the management of nutrient in infant formula and follow-up formula.

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.185-192
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• 1980

To study lipid components of Panax ginseng produced in Korea, the lipids of fresh ginsengs were extracted with the mixture of chloroform-methanol (2:1, v/v) and those of dried ginsengs were extracted with diethyl ether respectively. The lipid components extracted were separated and quantitated by column, thin layer and gas-liquid chromatographies. The results were summarized as follows : 1. Fresh ginseng contained 0.62% total lipid of which 45.28% were neutral lipids, 18.12% glycolipids, and 36.60% phospholipids. But dried ginseng contained 0.89% total lipids of which 86.48% were neutral lipids, 9.20% glycolipids, and 4.32% phospholipids. 2. Triglycerides (37.6 to 42.5% of the total neutral lipids) and sterol esters (16.5 to 19.6%) in all the fresh and dried ginseng were the major components among the neutral lipids. Monoglycerides, diglycerides, free fatty acids and free sterols were minor components. 3. Digalactosyl diglycerides (23.5% of the total glycolipids) in the fresh ginseng and steryl liglycosides (28.9%) in the dried ginseng were predominant components among the glycopids, respectively, Esterified steryl glycosides and monogalactosyl diglycerides were also identified, and four unknown spots in the fresh ginseng and two unknown spots in the dried ginseng were present. 4. Phosphatidyl cholines (31.3 to 31.9% of the total phospholipids) and phosphatidyl glycerols (34.8 to 36.7%) in all the fresh and dried ginseng were the major components among the phospholipids. Phosphatidyl inositols and phosphatidyl ethanolamines were also identified. 5. The major fatty acids in the fresh and dried ginseng were linoleic $(62.29{\sim}64.32%)$, palmitic $(13.16{\sim}15.63%)$, oleic $(5.73{sim}7.23%)$ and linolenic $(5.73{sim}7.23%)$. The fatty acid compositions in neutral lipid fraction was similar to the pattern in those of the total lipids. But glycolipid and phospholipid fractions contained a lower percent of linoleic acid and a higher percent of palmitic acid than the neutral lipid fraction.

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.193-199
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• 1980

A series of tests were conducted on the reesterification of rice bran oil containing high free fatty acids (acid value=119.7) with theoretical equivalent of glycerol. Test results showed that reaction rate (in terms of decrease in acid value) was increased as the reaction temperature was increased regardless of the presence of the catalyst and reaction time (42.7, 21.5 and 10.0 at $170^{\circ}C,\;210^{\circ}C\;and\;250^{\circ}C$, respectively) and as the reaction time was increased regardless of the temperature and the presence of the catalyst (31.1 vs 18.3 for 3 hrs vs 6 hrs). The presence of the catalyst (0.2% tin chloride) also accelerated the rate regardless of the reaction temperature and time (36.9 vs 12.5). Analysis by column chromatography showed that content of triglyceride in the oil was increased to 72.9% and 61.1% from 10.4% and content of free fatty acids in the oil was decreased to 1.4% and 6.1% from 60.2%, when the degummed oil was esterified at $250^{\circ}C$ for 6 hrs in the presence of and in the absence of the catalyst, respectively. The results estimated from the iodine values indicate that polymer formation was not significant, when the oil was esterified for 6 hrs at temperatures up to $210^{\circ}C$. However, it was somewhat significant for the oil esterified at $250^{\circ}C$ for 6 hrs. The catalyst did not affect the polymer formation. Analysis by high performance liquid chromatography showed that oleic acid (42.5%), linoleic acid (29.0%) and palmitic acid (20.3%) were the major fatty acid components of the rice bran oil.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.167-177
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• 2006

Both fish community and water quality in Lake Doam were investigated from September 2004 to August 2005. The turbidity of Lake Doam located in the upper region of the Songchun River in the South River system, Korea was high whole year due to the effects of distributed non point source pollutions in the watersheds. During the experimental periods, mean concentration of chlorophyll-a in epilimnetic layer (0 ${\sim}$ 5 m) was 18.5 ${\mu}g\;L^{-1}$ and transparency ranged from 0.3 m to 2.4 m. Average TP and TN concentrations were 111 ${\mu}g\;L^{-1}$ and 4.1 $mg\;L^{-1}$, respectively. Lake was classified as eutrophic state based on the nutrient concentrations suggested by U.S.EPA (1976). Total number of fish collected in Lake Doam was 9,600 individuals in 26 species of 6 family. Both dominant and subdominant species in the lake were P. herzi (34.9%) and Z. platypus (22.5%), respectively. Occurrence of water column species was high at upper region of the lake, whereas benthic type of species highly ,appeared in downstream area. The different fish assemblage between upper and lower area would be considered as the difference of bottom substrate and concentrations of suspended solids. In addition high appearance of Comat type of fish that is hybrid between gold fish (C, auratus) and C. auratus was found in the lake. It was unclear the reasons that high proportion of mutant species appeared in the lake. More researches are required in this area in future.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.263-270
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• 2010

This is a research on development of water purification equipment called artificial floating island (=AFI) for the stagnant water area which can secure exuberant landscape and water-friendility. The equipment devised in this study is designed to make up the weakness of conventional AFIs and improves the removal efficiency of pollutants using the mixture of media and plants. The air compressor positioned at the inlet releases air with inflow continuously, the water pump at the outlet sprays as a form of fountain with causing a disturbance on stable water column, then, both of them contribute improvement of water quality over a large area. We applied Bio-stone as a media in this system and performed an experiment of pre-efficiency test, and we concluded that the higher pollutants concentration of inflow, the higher removal efficiency we obtained. At the result of lab-scale experiment, in the case of high-concentration inflow, in the removal efficiency of SS is 62.2%, BOD is 50.2%, COD is 55.1%, T-N is 31.6%, T-P is 38.4%. In addition, to evaluate the field application, we set up the facilities in Sin-gal lake located in Yongin-Si Gyeonggi-Do, and researched on the removal efficiency of outflow relative to the inflow. As a result, SS is 53.5%, BOD is 32.8%, COD is 36.9%, T-N is 22.6%, T-N is 33.2%.

• Journal of Life Science
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• v.27 no.7
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• pp.796-804
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• 2017

This study was carried out to evaluate the antioxidant effect of methanolic extract of Houttuynia cordata (HCME) and to identify a compound having antioxidant effect. The ethyl acetate fraction of HCME showed the highest antioxidant effect in organic solvent fractions. The fraction was then separated into 12 fractions by open column chromatography. Among these fractions, the fraction 10 (Fr. 10) with the highest antioxidant activity was isolated, and its antioxidant effect was evaluated by DPPH radical scavenging activity, reducing power, TBARS, cell viability, DNA oxidation and DCF fluorescence. The Fr. 10 at a $64{\mu}g/ml$ showed 60% of inhibitory effect similar to that of vitamin C at $10{\mu}g/ml$, compared with blank group. The Fr. 10 at $64{\mu}g/ml$ showed 264% of reducing power, compared with blank group. TBARS assay showed that the Fr. 10 at $64{\mu}g/ml$ had 35.5% of inhibitory effect similar to that of vitamin E at $1,000{\mu}g/ml$, compared with blank group. The Fr. 10 above $32{\mu}g/ml$ displayed cytotoxicity. However, it was observed that the Fr. 10, above $1{\mu}g/ml$ reduced DNA damage. DCF fluorescence assay showed that the Fr. 10 inhibited oxidative stress by $H_2O_2$ in a dose dependent manner. The compound of Fr. 10 was identified to be rutin whose molecular weight is 610 by the IR and LC-MS analyses. Therefore, these results suggest that the rutin of Fr. 10 could use as a natural antioxidant for development of cosmetics and functional foods.

• Journal of Life Science
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• v.27 no.11
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• pp.1276-1289
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• 2017

This study isolated and purified the antimicrobial peptide McSSP-31 from an acidified hemocyte extract of a Mytilus coruscus. The antimicrobial peptide was purified by using a $C_{18}$ reversed-phase high-performance liquid chromatography (HPLC). The peptide was determined to be 3330.549 Da by matrix assisted-laser desorption ionization time-of-flight mass spectrophotometer (MALDI-TOF/MS). The N-terminus of a 14 amino-acid sequence was identified as P-S-P-T-R-R-S-T-S-R-S-K-S-R by Edman degradation method. The acquired sequence showed a 93% similarity with the sperm-specific protein Phi-1, which is from M. californianus. The identified open-reading frame (ORF) of peptide was 306 bp encoding 101 amino acids, which was analyzed by rapid amplification of cDNA ends (RACE), cloning and sequencing analysis. We compared the full sequence with other known proteins that reveal the sperm-specific protein Phi-1 (93.5%) of M. californianus. Synthesized antimicrobial peptide (McSSP-31) showed antibacterial activity against gram-positive bacteria including B. subtilis, S. mutans, S. aureus and gram-negative bacteria including E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa and fungi, C. albicans. Also, synthesized peptide showed strong antibacterial activity against antibiotic-resistant strains, including S. aureus. The cytotoxicity of the peptide was determined by using the HUVEC human cell line. The peptide did not exhibit any significant cytotoxic effects on the normal human cell line, and it had very low hemolytic activity with flounder hemoglobin. The results demonstrated that peptide purified from the hemocyte of a M. coruscus exhibits antibacterial activity against various bacteria and has the potential to be an alternative antibiotic agent.

• Journal of Life Science
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• v.22 no.11
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• pp.1456-1462
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• 2012

Sorafenib is a multikinase inhibitor and an oral anticancer drug approved for the treatment of patients with advanced renal cell carcinoma and those with unresectable hepatocellular carcinoma. The purpose of this study was to develop an efficient method of the determination of sorafenib in human plasma using tandem mass spectrometry coupled with liquid chromatography (LC/MS/MS) and validate the method by the guidelines of the Korean Food and Drug Administration (KFDA). Plasma samples ($100{\mu}l$) were added with chlorantraniliprole as an internal standard and then mixed with the 0.1% formic acid-containing extraction solution composed of isopropyl alcohol and ethyl acetate (1:4, v/v). After centrifugation, the supernatant was concentrated at $45^{\circ}C$ under negative pressure and centrifugal force. The residue was reconstituted with a mobile phase and injected into the HPLC instrument using a reverse phase Waters XTerra$^{TM}$ C18 column (particle size $3.5{\mu}m$). Liquid chromatography was carried out within the run time of 5 min using a mobile phase composed of buffer (0.1% formic acid and 10 mM ammonium formate), methanol, and acetonitrile (1:6:3, v/v/v). The analytes were monitored by tandem mass spectrometry in the multiple reaction monitoring method programmed to detect sorafenib at 'm/z 465.2 ${\rightarrow}$ 252.5' and chlorantraniliprole at 'm/z 484.4 ${\rightarrow}$ 286.2' with positive electrospray ionization mode ($ES^+$). The result showed the proper linearity ($r^2$ > 0.99) over the range of 2,000-5,000 ng/ml with good accuracy (90.7-103.9%) and precision (less than 10%). The newly developed method using LC/MS/MS was validated by the guideline of KFDA and identified as more sensitive compared to the previous methods.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.882-888
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• 2005

Procedure for analysis of methylmercury in fish was developed, involving addition of HCl, extraction with toluene, and clean-up using L-cystein solution. Obtained extract is analyzed by gas chromatography with electron capture detector using Ulbon HR-Thermon-Hg column. Detection limit and recovery of the method were 0.005mg/kg (expressed as Hg), 98-107 (103%), respectively. Total mercury and methylmercury concentrations in 175 commercial fish samples ranged from [mean-max (mean), unit: mg/kg]: 0.014-1.200 (0.270) and 0.006-0.901 (0.168) in tuna-fish, 0.020-0.934 (0.323) and 0.012-0.553 (0.149) in martin-fish, 0.082-0.782 (0.391) and 0.040-0.436(0.201) in shark, 0,023-0.031 (0.026) and 0,013-0.018 (0.015) in salmon, 0.098-0.193 (0.133) and 0.031-0.015(0.090) in tilefish, and 0,031-0.214 (0.089) and 0.016-0.093 (0.042) in canned tuna respectively. No sample of analyzed fish exceeded 1.0mg/kg wet wt., limit for methylmercury established by Codex. In all species examined, estimated weekly intake was lower than Provisional Tolerable Weekly Intake recommended by the JECFA (the Joint FAO/WHO Expert Committee on Food Additives).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1186-1194
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• 2017

Recently, many people have demanded reliable nutritional data even for minor-components. On the other hand, an analytical method for the analyses of vitamin $B_5$ and $B_6$ is lacking. Therefore, this study attempted to validate with accuracy and precision the analysis of vitamin $B_5$ and $B_6$ using a high-performance liquid chromatography (HPLC) method. The vitamin $B_5$ and $B_6$ contents were analyzed using an Agilent 1260 series HPLC system. YMC-Pack ODS-AM ($250{\times}4.6mm$ I.D.) and YMC-Pack Pro RS $C_{18}$ ($250{\times}4.6mm$ I.D.) columns were used for the analyses of vitamin $B_5$ and $B_6$, respectively. In the case of vitamin $B_5$, the flow rate was set to 1.0 mL/min by isocratic elution using the 50 mM $KH_2PO_4$ solution (pH 3.5)/acetonitrile (ACN) (95:5, v/v) with monitoring at 200 nm using HPLC/DAD, whereas the flow rate for vitamin $B_6$ was set to 1.0 mL/min of flow rate by isocratic elution using a 20 mM $CH_3CO_2Na$ solution (pH 3.6)/ACN (97:3, v/v) with monitoring by excitation at 290 nm and emission at 396 nm using HPLC/FLD. The column temperature was set to $30^{\circ}C$. The injection volume was $20{\mu}L$ for each experiment. The specificity of the accuracy and precision for vitamin $B_5$ and $B_6$ were also validated by HPLC. The results showed high linearity in the calibration curve for vitamin $B_5$ ($R^2=0.9998^{{\ast}{\ast}}$), the limit of detection (LOD) and limit of quantitation (LOQ) were 0.4 mg/L and 1.3 mg/L, respectively, In contrast, for the calibration curve of vitamin $B_6$, which showed high linearity ($R^2=0.9999^{{\ast}{\ast}}$), the LOD and LOQ were 0.006 mg/L and 0.02 mg/L, respectively.