• Food Science of Animal Resources
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• v.30 no.2
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• pp.313-320
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• 2010

The purpose of this study was to evaluate the freshness of chicken meat during 19 d of storage at $4^{\circ}C$ using a portable electronic nose. The portable system consisted of six different metal oxide sensors and a moisture sensor. Determination of volatile compounds with gas chromatography-mass spectrometry, total bacterial count (TBC), and 2-thiobarbituric acid reactive substances (TBARS) monitored the quality change of the samples. These results were compared with the results measured by the electronic nose system. TBC and TBARS measurements could be separated into five groups and seven groups, respectively, among ten groups. According to principal component analysis and linear discriminant analysis with the signals of the portable electronic nose, the sample groups could be clearly separated into eight groups and nine groups, respectively, among ten groups. The portable electronic nose demonstrated potential for evaluating freshness of stored chicken.

• Korean Journal of Organic Agriculture
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• v.28 no.1
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• pp.95-108
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• 2020

To develop an environment-friendly fungicide for controlling tomato wilt diseases, antifungal active substance was isolated Rheum australe D. Don roots against Fusarium oxysporum f. sp. lycopersici, a pathogen of tomato wilt, in this study. Methanol extract obtained from Rheum australe roots was successively fractionated with hexane, chloroform, ethyl acetate, butanol and water. The ethyl acetate fraction, which showed the highest antifungal activity, was separated by column chromatography, and 60 subfractions were obtained. The 60 subfractions were anlayzed for antifungal activities by bioassay. The active compound was identified as 5-[(E)-2- (3-hydroxy-4-methoxyphenyl)ethenyl]benzene-1,3-diol (rhapontigenin) by NMR and GC-MS analysis. As a result of testing antifungal activity of rhapontigenin against Fusarium oxysporum, EC₅₀ of rhapontigenin was showed strong antifungal activity at 7.48 mg/L. Therefore, this study showed that the Rheum australe roots extract can be a potential candidate which is a environment-friendly fungicide against Fusarium oxysporum.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.81-86
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• 2015

The purpose of our paper was to investigate the migration level of 4,4'-MDA(4,4'-methylenedianiline), 2,4-TDA(2,4-toluenediamine), aniline, acrylonitrile and methylmeth acrylate from plastic cookwares into food simulants and to evaluate the safety of each monomers. The test articles for monomers were PA (polyamide) items for 4,4'-MDA, 2,4-TDA and aniline, PU (polyurethane) items for 4,4'-MDA, ABS (acrylonitrile-butadiene- styrene) items for acrylonitrile, and acrylic resin items for methylmethacrylate. All the article samples of 321 intended for contact with foods were purchased in domestic market. 4,4'-MDA, 2,4-TDA and aniline were analyzed by LC-MS/MS (liquid chromatography -tandem mass spectrometer), acrylonitrile by GC-NPD (gas chromatography-nitrogen phos phorus detector) and methyl methacrylate by GC-FID (gas chromatography-flame ionization detector). The migration level of monomers were within the migration limits of Ministry of Food and Drug Safety (MFDS). As a result of safety evaluation, our results showed that the estimated daily intake (EDI, mg/kg bw/day)s were $2.39{\times}10^{-9}$ and $1.20{\times}10^{-9}$ for 4,4'-MDA and 2,4-TDA of PA, $4.32{\times}10^{-9}$ for acrylonitrile of ABS and $2.27{\times}10^{-7}$ for methylmethacrylate of acrylic resin. Reference Dose (RfD, mg/kg bw/day) of acrylonitrile and tolerable daily intake (TDI, mg/kg bw/day) of methacrylate were established respectively as 0.001 by EPA (US Environmental Protection Agency) and as 1.2 by WHO (World Health Organization). When comparing with RfD and TDI, the EDIs of acrylonitrile and methylmethacrylate accounted for $4.32{\times}10^{-4}%$ and $1.89{\times}10^{-5}%$ respectively.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.203-209
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• 2007

In order to promote utilization of the Yangha (Zinger mioga Rosc.) as functional food and natural spices, and 95.93%, from the dried one 7.63%, and from powder 9.81%, respectively. Crude protein content from the Yangha powder was 11.21%, and contents of crude fat, crude ash and crude fiber were 2.44%,10.78%, and 14.47%, respectively. Most of compositions from Yangha powder were higher than those from raw and the dried one, except fer water content. Antioxidative effect was investigated through Rancimat and DPPH methods. Oxidative stability of Yangha powder was the highest of4.21Al. Furthermore, the free radical scavenging activity of Yangha powder (76.61%) was higher than that of raw (49.35%) or the dried one (61.78%). Volatile flavor compounds of Yangha was extracted by steam distillation and extraction method. The extracts were analyzed and identified by gas chromatography and GC-MS spectrometry. One hundred twenty two volatile flavor components were identified, and the major component was terpene compounds including ${\alpha}$-pinene, ${\beta}$-pinene, ${\beta}$-phellandrene, 1,4-terpineol, and ${\beta}$-terpinene.

• Journal of Soil and Groundwater Environment
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• v.27 no.4
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• pp.37-48
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• 2022

Accurate analysis of petroleum hydrocarbons in soil is an important prerequisite for proper source tracking of contamination. Identification of petroleum compounds is commonly carried out by peak pattern matching in gas chromatography. However, this method has several technical limitations, especially when the soils underwent biological, physical and chemical transformation. For instance, it is very difficult to distinguish jet fuel (JP-8) from kerosene because JP-8 is derivatized from secondary reaction between chemical agents (e.g. anti-oxidants, antifreezer and so on) and kerosene. In this study, an alternative method to separately analyze JP-8 and kerosene in the petroleum hydrocarbon contaminated soil was proposed. Qualitative analyses were performed for representative phenolic antioxidants [2,6-di-tert-butyl phenol (2,6-DTBP), 2,4-di-tert- butylphenol(2,4-DTBP), 2,6-di-tert-butyl-4-methyl phenol (2,6-DTBMP)] using a two dimensional gas chromatograph mass spectrometer (2D GC×GC-TOF-MS). This qualitative analysis of antioxidants in soil would be a useful complementary tool for the peak pattern matching method to identify JP-8 contamination in soil.

• Journal of Life Science
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• v.19 no.12
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• pp.1815-1820
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• 2009

This study was conducted to investigate the physicochemical compositions in the root, stem and fruit of A. chilsanensis. The contents of crude fat were 2.09, 2.51 and 7.94%, and crude proteins were 11.50%, 7.18% and 10.17%, respectively. Crude ash levels were 11.07, 6.85 and 6.38%, respectively, and it was higher in root than stem or fruit. The contents of reducing sugar were 18.90, 10.70 and 24.05 g/100 g in the root, stem and fruit of A. chilsanensis. As a result of color measurement, L value (lightness) of stem, a value (redness) of fruit and b value (yellowness) of root were high, respectively. The content of free sugar was high in all root, stem and fruit, in order of fructose, glucose and sucrose. Acanthoside-D, the main factor of A. chilsanensis, was 18.95 mg/100 g in stem, 8.10 mg/100 g in root and 2.85 mg100 g in fruit. Free amino acid in stem was 955.26 mg/100 g, which was 4.5 times higher than in stem and 8.5 times higher than in fruit. Natural aromas were identified by GC/GC-MS. Natural aromas such as $\alpha$-pinene, $\beta$-pinene, 3-carene and D-limonene were detected in A. chilsanensis.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.96-106
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• 2017

This study aims to identify the chemical compositions and antioxidant activities of essential oil, extracted from the leaves of Neolitsea aciculata (Blume) Koidz by the hydrodistillation method. To the end, the chemical composition of N. aciculata leaf oil was firstly analyzed through GC/MS. The major constituents of essential oil were found to be: cis-ocimene (11.00%), trans-ocimene (9.65%), elemol (9.15%), ${\beta}$-elemene (8.75%), germacrene-D (7.55%), trans-caryophyllene (5.90%), ${\gamma}$-elemene (5.40%) and ${\tau}$-muurolol (4.95%). Then, the antioxidant potential of the essential oil was evaluated by the methods of total polyphenolic content (TPC) assay, DPPH radical scavenging activity, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP). It was estimated that the total polyphenolic content of the oil was $136.7{\pm}0.13\;mg\;GAE/g$ and the efficient concentration of the oil required to scavenge 50% DPPH radicals ($EC_{50}$ value) was $639.33\;{\mu}g/m{\ell}$. Also, ABTS radical scavenging activity was identified to be concentration dependent, while the FRAP value was $31.21{\pm}0.12\;{\mu}M$ $FeSO_4{\cdot}7H_2O/g$. Such figures, as a result, suggest that the essential oil extracted from the leaves of N. aciculata has its antioxidant activity, which can serve as significant health functional benefits.

• Clean Technology
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• v.24 no.1
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• pp.70-76
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• 2018

Pyrolysis of Saccharina japonica in an Auger reactor was conducted by varying the temperature and the auger speed and then physicochemical properties of the S. japonica-derived pyrolysis oil were analyzed. The maximum yield of S. japonica-derived pyrolysis oil (32 wt%) was obtained at a pyrolysis temperature of $412^{\circ}C$ and an auger speed of 20 rpm. Due to low carbon content and high oxygen content in the pyrolysis oil, the higher heating value of S. japonica-derived pyrolysis oil was $23.6MJ\;kg^{-1}$, which was about 60% that of conventional hydrocarbon fuels. By GC/MS analysis, 1,4-Anhydro-d-galactitol, dianhydromannitol, 1-hydroxy 2-propanone and isosorbide were identified as the main chemical compounds of S. japonica-derived pyrolysis oil. The bio-char has low higher heating value ($13.0MJ\;kg^{-1}$) due to low carbon content and high oxygen content and contains a large amount of inorganic components and sulfur.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.191-197
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• 2015

We investigated the physicochemical properties and volatile flavor compounds in Taiwan Apple Mango (TAM) and Philippines Carabao Mango (PCM). The volatile flavor compounds were extracted using solid-phase microextraction (SPME) and analyzed by GC/MS. TAM and PCM have significantly different chemical composition, except for their crude ash. The moisture and crude fat contents were higher in TAM, whereas the crude protein and carbohydrate contents were higher in PCM. The major free sugars in order of concentration were sucrose, fructose, and glucose. We identified 56 and 59 volatile flavor compounds in TAM and PCM, respectively. Terpenes and their derivatives comprised 94.42% of the volatile flavor compounds in TAM, but only 63.79% of those in PCM. The acidic compound contents were higher in PCM than in TAM. ${\delta}$-3-Carene was the dominant flavor compound in these two mango cultivars. ${\alpha}$-Copaene, ${\alpha}$-guaiene, germacrene D, ${\alpha}$-bulnesene, and ${\gamma}$-gurjunene were found only in TAM, whereas ${\beta}$-myrcene, ${\alpha}$-phellandrene, ${\beta}$-phellandrene, ${\alpha}$-terpinolene, and cis-3-hexenyl butyrate were identified in PCM. Based on the results, we suggest that these compounds might contribute to the distinguishing flavor properties in different varieties of mango.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.263-268
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• 2009

The acaricidal activities of Illicium verum fruit-derived materials against adults of Dermanyssus gallinae were examined using the direct contact application method. Based on laboratory tests, an acaricidal constituent of I. verum fruit was determined because of its potent activity. Results were compared with those of the currently used acaricides such as dichlorvos, diazinon, and carbaryl. The acaricidal principle of I. verum fruit was identified as (E)-anethole using a GC-MS. lts acaricidal activity was compared with those of 12 compounds having a similar chemical moiety. Based on the $LD_{50}$ values, the acaricidal activities of (+)-or-(-)-neomenthol were the strongest (0.01 $mg/cm^2$) and (E)-anethole, (+)-or-(-)-menthol, (${\pm}$)-isoborneol, (-)-menthone, and (lS)-endo-(-)-bomeol showed similar results (0.02 $mg/cm^2$), and (1R)-(+)-camphor and (+)-menthone also gave good activities (0.03 and 0.04 $mg/cm^2$, respectively). These compounds showed more toxic acaricidal activities than diazinon and carbaryl, 0.05 and > 0.2 $mg/cm^2$, respectively, but were not comparable to that of dichlorvos with 0.0002 $mg/cm^2$. These results indicate that the I. verum fruit-derived materials and tested compounds descried as poultry red mites-control agents could be useful for managing field populations of D. gallinae.