• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.324-329
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• 2019

Volatile flavor compounds of radish fermented by lactic acid bacteria were extracted using solid-phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 45 volatile flavor compounds were identified. The volatile flavor compounds in unfermented radish mostly consisted of sulfur-containing compounds (95.85%) and aldehydes (2.61%). While the composition ratio of volatile flavor compounds in radish fermented for two days changed to sulfur-containing compounds (75.53%) and acids (11.12%). As the fermentation period was increased, the contents of dimethyl disulfide, dimethyl trisulfide, diallyl sulfide, diallyl disulfide, and diallyl trisulfide, which have unique garlic and scallion flavor, decreased, and acetic acid and 1-hexanol, which have a sour and fruity flavor, increased. These changes in volatile flavor compounds seemed to have affected the flavor characteristics of fermented radish.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.793-802
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• 2009

Adsorption properties were estimated for the organic silicon compounds (siloxanes) in an actual landfill gas (LFG) using adsorbents such as coconut activated carbon, coal activated carbon, silica gel, sulfur adsorbent, carbonized sludge, and molecular sieve 13X. Coconut activated carbon showed the highest removal efficiency of more than 95%. The desorption of hexamethyldisiloxane (L2) from the adsorbent, however, resulted in the remarkable concentration variation of the compound in the treated gas. Silica gel, which had high adsorption capacity for L2 in single substance adsorption experiment in the other study, could not remove the component in the actual landfill gas while it adsorbed well octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in the LFG. Therefore the elimination of hexamethyldisiloxane is an important factor to determine the level of total organosilicon compound in pretreated landfill gas. Moreover, the L2 from the actual landfill gas was effectively adsorbed by the serial adsorption test using two columns packed with coconut activated carbon which has the great capacity of siloxanes removal among others. In order to utilize efficiently LFG as a renewable energy, the emission and adsorptive characteristics of the substance to be treated should be considered for the organization, operation, and management of pretreatment process.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.170-176
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• 1976

In order to analyze the composition of fatty acid in the seed oil. and amino acid in the seed protein of wild thornless chinese pepper tree; Zanthoxylum schinifolum var. inermis Nakai. GLC method and amino acid autoanalyzer were applied. respectively. while the general composition of the seed and physico-chemical properties of the seed oil were also determined by A. O. A. C. method. The results obtained were summarized as follow The content of oil, protein and ashes were 47.05%, 20.14% and 3.1%, respectively. The content of sulfur and cyan compound in the seed were 0.02% and 0.00005%, respectively, which were far below than allowed guantity by food regulation. Therefore, it is considered to be safe for edible purpose. The iodine absorption number obtained was 145.2, which might be belonged to drying oil. The physico-chemical properties of the seed oil such as acid value, saponification number and refractive index showed the characteristics of an unsaturated high molecular fatty acid compound. The seed oil was composed of 34.8% of oleic acid, 25.1% of linoleic acid and 26.1% of linolenic acid, which accounts for more than 80% of essential fatty acid. Therefore, it could be used as an edible oil. Seventeen kinds of amino acids were anayzed from seed protein. Among them comparatively high content of threonine, valine, methionine, isoleucine, leucine and phenylalanine were observed. As a non-essential amino acid, glutamic acid was found as high as 4.985%. From these results the seed of thornless Chinese pepper would be good for oil and protein source.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.537-542
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• 2016

In this study, we have prepared mesophase pitch from pyrolysis fuel oil (PFO) by heterogeneous reforming process. This process was conducted by direct fluorination at various temperature and followed by the heat treatment at $390^{\circ}C$. The reformed pitch was then investigated by softening point analysis, elemental analysis, fourier-transform infrared spectroscopy, high resolution X-ray diffraction and polarization microscope analysis. Carbon contents of reformed pitch increased according to increasing the reaction temperature of fluorination, while oxygen, nitrogen and sulfur contents were completely eliminated. As the fluorination temperature increased, the creation, growth, coalescence and alignment process of mesophase spheres were observed. Also the interlayer spacing of carbon hexagonal planar structure decreased, while its crystalline size increased. In addition, aromatic ring compound contents increased by the condensation polymerization of aliphatic compound. These results can be attributed to the radical reactivity of the fluorine increased as the reaction temperature increased. It was considered that the fluorination reaction could help PFO to generate aromatic compounds, via promoting polymerization by radical reaction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.122-129
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• 2002

In order to elucidate a responsible mechanism for the development of the odor characteristics of cooked desirable flavoring materials such as crab and shrimp, shore swimming crab flesh were extracted with various solvents and resulting extracts were evaluated organoleptically after cooking. As a result, $80\%$ aqueous methanol extract (AME) was found to produce a cooked desirable flavoring odor. After dialysis of AME, outer dialyzate was fractionated by ionexchange column chromatography, and each of the fraction obtained was subjected to cooking, fellowed by organoleptic evaluation. The outer dialyzate fraction, acidic and amphoteric fraction produced a cooked crab-like odor, On the basis of the composition of $80\%$ AME, an artificial crab extract was prepared with pure chemicals. The artificial crab extract thus obtained closely resembled $80\%$ AME in respect of the cooked odor. To elucidate the role of individual components, the artificial extracts from which certain component alone or as group was omitted were subjected to organoleptic evaluation after cooking. All of neutral, acidic, basic, and sulfur containing amino acids and quarternary base compounds were involved in the development of the cooked crab-like odor. The cooked odor of artificial extract without addition of ribose was lacking in the characteristics of cooked crab odor, and phosphorus compound accelerated the development of the cooked crab-like odor.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.105-115
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• 2013

Maillard reaction flavors had been tried by using krill hydrolysate and precursors in order to develop Teriyaki sauce with the reaction flavors. Also, the study for applying krill to Teriyaki sauce had been tried by using krill instead of eel bones. To make boiled-type and grilled-type reaction flavors, krill hydrolysate was used with other precursors such as serine, glucose and glucosamine. In the dynamic analysis of headspace volatile compounds, 20 mL reaction flavor was analyzed by the combined system of purge & trap, automatic desorber, gas chromatography and mass selective detector. Three kinds of Teriyaki sauce were developed with reaction flavor, krill and eel bones, and their products were evaluated by 10 items of cooked vegetables, cooked potatoes, boiled shrimp, grilled shrimp, fishy smell, pungent aroma, burned smell, sweety aroma, chemical smell, mud smell and preference. In the results of headspace analysis, 35 and 33 volatile compounds were identified from grilled-type and boiled-type reaction flavors. Grilled-type had sulfur-containing, aliphatic compounds, alcohols, ketones, pyrazines, and other aromatic compounds, and grilled-type had aldehydes, furans, other nitrogen-containing compounds. In the sensory evaluation of Teriyaki sauce, the items of roasted shrimp and sweety aroma showed significant differences for grilled-type application to Teriyaki sauce. The above results show the possible application of grilled-type reaction flavor to Teriyaki sauce.

• Elastomers and Composites
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• v.36 no.2
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• pp.111-120
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• 2001

Mechanical properties and their adhesion behavior with zinc- and brass-plated steel cords of natural rubber/acrylonitrile-butadiene blend compounds were investigated as a function of blend ratio. The Mooney viscosity and stress relaxation time were found to be lowered with increasing NBR content. Tensile modulus generally increased with increasing NBR content. Tensile stress at break stayed constant up to about 40 phr and showed minimum at $50{\sim}60 phr$, and thereafter increased with increasing NBR content. Strain at break decreased linearly below 50 phr, and above the level it showed nearly constant value. Based on the abrupt drops in elastic modulus and tan ${\delta}$ peak, the glass transition temperature of NR and NBR were found to be -55 and $-10^{\circ}C$, respectively. In the case of NR/NBR blend compounds, two distinct transition points were observed and each transition position was not affected by NBR level indicating an incompatible nature of NR/NBR blend system. The pullout force and rubber coverage decreased to the level of about 40% to that of pure m compound, when the 50 phr of NR was replaced by NBR. However, the pure NBR compound showed the comparable adhesion performance with NR(${\sim}90%$). The sulfur concentration was found to become lower with the increased NBR content at the adhesion interface based on the Auger spectrometer results, representing a lack of adhesion layer formation, and this was explained for a possible cause of low adhesion performance with adding NBR.

• Analytical Science and Technology
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• v.17 no.2
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• pp.145-152
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• 2004

In this study, analytical characteristics of S gas detection technique were investigated against four major reduced S compounds (including hydrogen sulfide; methyl mercaptan; dimethyl sulfide (DMS); and dimethyl disulfide (DMDS)). To analyze such properties, an analytical system was constructed by combining the GC/PFPD system with the loop injection method. The results of our analysis indicated that response behavior of S gases differs greatly between compounds; H2S exhibited the weakest sensitivity of all compounds, while DMDS with two S-atom compounds the strongest sensitivity. To learn more about their response behavior on GC/PFPD method, their calibration patterns were compared using the three arbitrarily set concentration ranges of low, intermediate, and high. The results showed that calibration patterns of each compound are distinguished because of different factors. There was a line of evidence that calibration of $H_2S$ was affected noticeably by adsorptive loss within the system, whereas those of DMS and DMDS were influenced most sensitively by such factor as the linearity response at a given PMT voltage setting. The overall results of our study suggest that quantification of malordorous S compounds require a better knowledge of compound-specific response behavior against GC detection.

• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.15-19
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• 2008

The most typical capping method for concrete structures is a sulfur-mortar compound capping, provided it satisfied the standard criterion set forth by ASTM C 617, but this conventional bonded-type method has many problems. It exhibits relatively the smaller unreliable value of the strength of high-strength concrete due to the differences of elasticity and strength between the cylinder and the cap, and manifests poor serviceability such as dangerous working tasks or a waste of the working time. To prevent these problems, unbonded-type capping methods have taken the place of the conventional methods in recent years. One of the popular methods is the use of synthetic rubber like a neoprene pad. Serious problems still remain in this method, which include the consideration of its chemical characteristics in consideration of the selection, the safekeeping and the economy of the pads. Moreover, the synthetic rubber pads cannot be used in concrete cylinder with strength greater than 80 MPa according to ASTM C 1231-00. New 'sand-capping method' presented in this study, can be applicable to the compressive strength evaluation of the high strength concrete in the range of $70{\sim}100\;MPa$. This new method has better simplicity and reliability than those of existing 'sand-box', because usual materials such as standard sand and simply-devised apparatus are used for the capping system. The statistical analysis of the test results revealed that the new sand-capping method exhibited the smallest deviation and dispersion, attesting for its much better reliability than other methods specified in ASTM C 1231/1231M.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.713-729
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• 2020

The aim of this study was to develop retorted samgyetang marinated with different levels of soy sauce and processed at different F₀ (thermal death time at 121℃) values. The tested marinade series comprised different percentages of soy sauce in water (0%, 25%, and 50% [w/w]) containing a fixed concentration of sodium tripolyphosphate (0.3% [w/w]). Following marination, samgyetang was prepared and subjected to retort processing, until an F₀ value of either 8 or 29 was achieved. Meat quality analysis of the breast meat, sensory evaluation, and aroma analysis were performed as indicators of acceptability. The meat pH decreased as the soy sauce content increased, regardless of the F₀ value. The shear force value significantly decreased as the concentration of soy sauce increased, but increased as the F₀ value increased (p < 0.05). Lipid oxidation was not affected by marination, but increased significantly as the F₀ value increased (p < 0.05). The proportion of polyunsaturated fatty acids decreased significantly (p < 0.05) as the F₀ value increased. The total alkane content decreased as the F₀ value increased (p < 0.05). Changes in the total volatile sulfur compound and 2-butyl-1-octanol content were affected by soy sauce marination. Marination using 25% soy sauce and retort sterilization, until an F₀ value of either 8 or 29 was achieved, improved the acceptability of samgyetang. Therefore, marination using 25% soy sauce and retort sterilization until an F₀ value of 8 is the process recommended for developing a soy sauce-flavored, retorted samgyetang product of acceptable quality.