• Applied Biological Chemistry
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• v.42 no.2
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• pp.111-115
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• 1999

This study was attempted to develop technique of masking the pungent odor of chonggugjang using two-stage fermentation method with mixed pure cultures. Cooked soybeans were fermented with Lactobacilli or Aspergillus oryzae at $38^{\circ}C$ for 36 hrs, and then re-fermented with Bacillus subtilis for 12 hrs. The volatile compounds of chonggugjang were obtained with a SDE(Simultaneous steam Distillation and solvent Extraction) system and the extracts were identified by GC and GC-MS. The experimental results revealed the presence of 35 volatile compounds in control chonggugjang(only Bacillus subtilis inoculation). Among them, the major volatile compounds were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine. Twenty-nine kinds of volatile compounds were in chonggugjang prepared by two-stage fermentation method with Lactobacilli and Bacillus subtilis(II), and major volatile compounds were identified to be 2,3,5-trimethyl pyrazine and 2,5-dimethyl Pyrazine. In chonggugjang(Asp. oryzae and then Bacillus subtilis inoculation(III)), the contents of hexadecanoic acid and 2-methyl pyrazine were patricularly high and the main components of chonggugjang fermented with rice straw(IV) were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine etc. In conclusion, the flavor compounds such as 2, 5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine were increased by the inoculation of Lactobacilli or Asp. oryzae, where as unpleasant odor components-butyric acid and valeric acid were decreased. Compared with volatile compounds of chonggugjang made from different soybean cultivars, the flavor compounds (2-methyl pyrazine 2,5-dimethyl pyrazine 2,6-dimethyl pyrazine 2,3-dimethyl pyrazine 2-acetyl pyrazine 2,3,5-trimethyl pyrazine 2-ethyl-3,5-dimethyl pyrazine) of chonggugiang prepared with Sinpaldalkong were high.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.135-144
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• 2007

The dried barks of Maackia amurensis were ground, extracted with 95% EtOH, concentrated, and fractionated with a series of light petroleum ether, dichloromethane, ethyl acetate and water on a separatory funnel. Each fraction was concentrated, then a portion of dichloromethane and ethyl acetate soluble was chromatographed on a Sephadex LH-20 and silica gel 60 column using a various solvent system as eluents. The isolated compounds were identified by cellulose TLC, $^1H-$, $^{13}C-NMR$, COSY, NOESY, HMQC, HMBC, FAB and EI-MS. The structures were determined as: 7-O-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl(1''''->6''')-$\beta$-D-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyransoyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl-4', 6-dimethoxyisoflavone. The Free radical scavenging activity using DPPH of the isolated compounds were similar with that of BHT but lower than of $\alpha$-tocopherol.

• Analytical Science and Technology
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• v.13 no.5
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• pp.683-692
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• 2000

The volatile organic compounds emitted from food wrapping films when it was used at high temperatures. However, the testing method based on solvent extraction may not be suitable for determination of volatile organic compounds from food wrapping films. Therefore, thermal extraction device was investigated in the study for reflection of actual usage conditions at home and restaurant. In this study, PVC food wrapping films were exposed to normal use condition controlled from $50^{\circ}C$ to $120^{\circ}C$ and collected on sorbent trap. Then, emitted VOCs from the films were analyzed with On-column cryofocusing-GC/MS system. The major VOCs emitted from films were $C_{12}-C_{18}$ paraffinic hydrocarbons, dimethylphthalate, alkylphenols, known as endocrine disrupting chemical, such as tetramethylbutylphenol, tert-butylphenol, and nonylphenol. The concentration of tetramethylbutylphenol emitted from PVC films was $0.07ng/cm^2$ at $50^{\circ}C$, rapidly increased with temperature, $3.94ng/cm^2$ at $100^{\circ}C$.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.328-332
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• 2010

In this study, porous ZnO sphere and Cu-ZnO composite were synthesized by coprecipitation method in diethylene glycol solvent. The physicochemical properties of as-prepared composite materials were characterized by SEM, XRD, $N_2$-sorption and $H_2$-TPR. A series of porous Cu-ZnO with different Cu contents (0, 6.6, 21.3, 36.4, 54.6, 77.8 wt%) was investigated for CO oxidation activity in a fixed bed reactor system. With increasing Cu content in Cu-ZnO the surface area and micropore volume of Cu-ZnO are decreased and Cu (36.4 wt%)-ZnO shows higher activity for CO oxidation compared to the others.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.122-130
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• 2009

Maillard reaction products (MRPs) were produced from aqueous solution of various sugars with hydrolyzed wheat gluten (HWG) with different temperatures, pressures, pH values and solvents. The physicochemical properties of MRPs were investigated and DPPH and hydroxyl radical scavenging activity and sensory properties were also assessed. MRPs from ribose and HWG evidenced the highest preference for meaty flavor and antioxidant activity and also evidenced higher antioxidant activity with larger pH reductions and higher browning index increases than were observed in other MRPs. The antioxidant activities were increased with increased reaction temperature and pressure. The most preferred meaty flavor was obtained from MRPs with ribose at 140$^{\circ}C$ in an oil bath with the pH adjusted to 9 in water as a solvent, and heated for 30 mins.

• Analytical Science and Technology
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• v.18 no.3
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• pp.201-205
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• 2005

Tri-octyl amine (TOA) is used in solvent extraction process for radioactive waste. This compound may be degraded to di-octyl amine (DOA), mono-octyl amine (MOA) by radioactive materials. Amount of TOA, DOA and MOA in TOA must be monitored because they production of these compounds means degradation of which leads to a decrease in the extraction yield. Retention behavior for TOA, DOA and MOA are studied with Phenomenex LUNA-$C_{18}$ ($4.6mm{\times}25cm$) analytical column and $CH_3OH:H_2O$ (50 mmol $CH_3COONH_4$) eluent by liquid chromatography. Optimum condition for these compounds is $CH_3OH:H_2O$ (50 mmol $CH_3COONH_4$) = 85 : 15 ratio. TOA, DOA and MOA compounds is well separated within 20 minute. Dynamic range is $30{\sim}160{\mu}g/mL$ for TOA, $5{\sim}100{\mu}g/mL$ for DOA and $0.1{\sim}5{\mu}g/mL$ for MOA, respectively. The detection limit are $0.1{\mu}g/mL$ for TOA, $1{\mu}g/mL$ for DOA (in SCAN mode) and $0.1{\mu}g/mL$ for MOA (in SIM mode) in this system with $20{\mu}L$ sample loop.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.102-108
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• 2008

Many alternative biocidal additives were applied to antifouling paint to replace TBT, and Sea-Nine 211 is one of alternating organic booster compounds used in antifouling paint. In this study, extent of Sea-Nine 211 toxicity on marine benthic bivalve is evaluated. Sea-Nine 211 was injected to surf clam, Pseudocardium sachalinensis, that inhabitate northern part of Gangwon Province, Korea. Survival rate of the clam and xenobiotics metabolizing enzyme activities in digestive gland were measured during 4 day-exposure period. The results were compared with those of TBT exposed clam. There were no mortality of clam in the solvent (DMSO) control group and the three Sea-Nine 211 exposure groups (5, 25, 50 mg kg$^{-1}$ body weight), while the clam exposed to 1, 2 and 5 mg kg$^{-1}$ TBT chloride (TBTC) demonstrated 70, 30 and 0% survival rate, respectively. The Sea-Nine 211 exposure group showed a tendency of cytochrome P450 (CYP) induction according to the exposure duration, on the other hand, CYP content was decreased in the TBT exposure group. NADPH cytochrome P450 reductase activity slightly increase according to the exposure duration in the Sea-Nine 211 exposure group, while TBTC inhibit its activity as CYP content. Moreover, there was no significant change of NADH cytochrome b5 reductate activity in the clam epxosed to Sea-Nine 211. In the TBTC exposure group, its activity increased in early exposure period and then significantly decreased the rest of exposure period. All the results indicate that Sea-Nine 211 demonstrated a tendency to induce CYP level, while TBTC inhibits the CYP level, NADPH cytochrome P450 reductase and NADH cytochrome b5 reductase activities.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.532-537
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• 2014

Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections, and infections of the body surface. Many analytical methods have been used to study oriental herbal medicines, such as thin-layer chromatography, column liquid chromatography, and high performance liquid chromatography (HPLC). In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out in order to separate pure compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 mL/min in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. The $^1H$ NMR spectrum revealed that the resonances at ${\delta}$ 4.10 and 4.20 ppm corresponded to three protons ($-OCH_3$), whereas those at ${\delta}$ 6.10 ppm corresponded to two protons ($-OCH_2O-$). Further, two aromatic protons (H-11 and H-12) conveys a doublet-doublet pattern. The H-11 doublet and H-12 doublet appear at ${\delta}$ 7.98 and 8.11, respectively. The $^{13}C$ NMR. spectrum showed a tetrasubstituted with a methylenedioxy group at C2 and C3, and two methoxy groups at C9 and C10. The chemical structure of the berberine was identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1100-1106
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• 2008

In this study, we presented rapid and simple fabrication method of functionalized surface on various substrates as a universal platform for the selective immobilization of cells. The functionalized surface was achieved by using deposition of polyelectrolyte such as poly(allyamine hydrochloride) (PAH), poly(diallyldimethyl ammonium chloride) (PDAC), poly(4-ammonium styrene sulfonic acid) (PSS), poly(acrylic acid) (PAA) and fabrication of poly(ethylene glycol) (PEG) microstructure through micro-molding in capillaries (MIMIC) technique on each glass, poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(dimethyl siloxane) (PDMS) substrate. The polyelectrolyte multilayer provides adhesion force via strong electrostatic attraction between cell and surface. On the other hand, PEG microstructures also lead to prevent non-specific binding of cells because of physical and biological barrier. The characteristic of each modified surface was examined by using static contact angle measurement. The modified surface onto several substrates provides appropriate environment for cellular adhesion, which is essential technology for cell patterning with high yield and viability in the micropatterning technology. The proposed method is reproducible, convenient and rapid. In addition, the fabrication process is environmentally friendly process due to the no use of harsh solvent. It can be applied to the fabrication of biological sensor, biomolecules patterning, microelectronics devices, screening system, and study of cell-surface interaction.

• Clean Technology
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• v.17 no.4
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• pp.285-299
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• 2011

As one of the REACH obligations, the extended safety data sheet (eSDS) should be communicated within the supply chain under the REACH Regulation. Based on technical guidance documents published on the ECHAs website and survey of EU's recent REACH-related informations, this paper includes a study on details of how to develop exposure scenarios (ES) such as structure of ES, process of ES develpoment, standard workflows and key input data to develop ES with an introduction of eSDS concept. This paper also contains an overview on operational conditions (OCs) and risk management measures (RMMs) that are what to consider when building an ES. The structure of Chesar (Chemical Safety Assessment and Report tool) developed by European Chemicals Agency (ECHA) is studied with a review of the available exposure estimation tools for workers, environment and consumers. Case example of generic exposure scenario (GES) for organic solvent is presented. To guide Korean EU-exporting companies, their participating roles in three steps of preparing ES are addressed.