• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.170-176
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• 1984

This study was directed to define the taste compounds of crucian carp, Carassius caressius, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals in the extracts of crucian carp were analyzed, and then followed by sensory evaluation of synthetic extracts prepared from 44 pure chemicals on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, histidine was dominant occupying $46\%$ of the total free amino acids. The other abundant free amino acids were glycine, lysine, alanine and taurine. As for the nucleotides, IMP was dominant showing about $80\%$ of the total of nucleotides. The most abundant organic base was total creatinine. The content of betaine was poor and TMAO were trace in content. The main organic acids were succinic, propionic, butyric and valeric acid. Small amount of glucose, fructose and inositol were detected and ribose and arabinose were trace in content $K^+,\;Na^+,\;PO_4^{3-}\;and\;Cl^-$ were found to be the major ions and small amount of $Ca^{++}\;and\;Mg^{2+}$ were deleted. Judging from the results of omission test, the major components which contribute to produce the taste were serine, glutamic acid, lysine, arginine, tyrosine, phenylalanine, IMP, $Na^+,\;K^+\;and\;PO_4^{3-}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.177-183
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• 1984

This study aims to find the taste compounds of wild loach, Misgurnis mizolepis, which is important fresh-water fish in this country. In order to elucidate the origin of the taste of wild loach meat, free amino acids, organic bases, nucleotides and their related compounds, organic acids, sugars and minerals were analyzed, and then followed by organoleptic test of synthetic extract prepared on the basis of the analytical data. Sensory evaluations of synthetic extracts prepared by omitting each extractive components were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, histidine, threonine, glycine, lysine, alanine were abundant. IMP and AMP were dominant in the wild loach in content. Total creatinine and butyric acid were abundant. As for the minerals, $Na^+,\;K^+,\;Cl^-\;and\;PO_4^{3-}$ were found to be the major ions. From the results of omission test of synthetic extracts the major components which contribute to produce the taste were arginine, glutamic acid, valine, aspartic acid, IMP, succinic acid, $Na^+,\;K^+,\;Ca^{2+}\;Mg^{2+}\;Cl^-\;and\;PO_4^{3-}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.33-39
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• 1984

In order to elucidate the taste compounds of wild eel, Anguilla japonica, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals were analyzed, and then followed by organoleptic test of synthetic extract prepared on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in profile were assessed. In free amino acid composition, lysine was dominant occupying $25\%$ of total free amino acid. The other abundant amino acids were glycine, arginine, alanine and histidine. From the results of analysis of nucleotides, IMP was dominant showing about $70\%$ of total nucleotides while ATP, ADP, AMP, inosine and hypoxanthine were low in content. Among organic bases total creatinine was abundant. The amount of betaine was 24 mg/100 g. The main organic acid were butyric acid, valeric acid and succinic acid. As for the sugars, glucose and inositol were 1-2 mg/ 100g in content. $K^+,\;Na^+,\;PO_{4}^{3-}\;and\;Cl^-$ were found to be the major ions. From the results of omission test the major components which contribute to produce the taste were glycine, serine, glutamic acid, IMP, $Na^+,\;K^+,\;Cl^-,\;PO_{4}^{3-}$, lysine, alanine, isoleucine, aspartic acid and creatinine.

• Ocean and Polar Research
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• v.37 no.2
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• pp.127-140
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• 2015

A continuous series of 60 snow samples was collected at a 2.5-cm interval from a 1.5-m snow pit at a site on the Styx Glacier Plateau in Victoria Land, Antarctica, during the 2011/2012 austral summer season. Various chemical components (${\delta}D$, ${\delta}^{18}O$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $SO_4{^2-}$, $NO_3{^-}$, $F^-$, $CH_3SO_3{^-}$, $CH_3CO_2{^-}$ and $HCO_2{^-}$) were determined to understand the highly resolved seasonal variations of these species in the coastal atmosphere near the Antarctic Jang Bogo station. Based on vertical profiles of ${\delta}^{18}O$, $NO_3{^-}$and MSA, which showed prominent seasonal changes in concentrations, the snow samples were dated to cover the time period from 2009 austral winter to 2012 austral summer with a mean accumulation rate of $226kgH_2Om^{-2}yr^{-1}$. Our snow profiles show pronounced seasonal variations for all the measured chemical species with a different pattern between different species. The distinctive feature of the occurrence patterns of the seasonal variations is clearly linked to changes in the relative strength of contributions from various natural sources (sea salt spray, volcanoes, crust-derived dust, and marine biogenic activities) during different short-term periods. The results allow us to understand the transport pathways and input mechanisms for each species and provide valuable information that will be useful for investigating long-term (decades to century scale periods) climate and environmental changes that can be deduced from an ice core to be retrieved from the Styx Glacier Plateau in the near future.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.365-374
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• 2003

Various deleterious chemicals can be introduced to existing concrete structures from various external sources. The deterioration of concrete by seawater attack is involved in complex processes due to various elements contained in seawater. In the present study, attention was paid to the formation of secondary minerals and characteristics of mineralogical and micro-structural changes involved in concrete deterioration caused by the influence of major seawater composition. The characteristics of deterioration occurred in existing concrete structures was carefully observed and samples were collected at many locations of coastal areas in Busan-Kyungnam. The petrographic, XRD, SEM/EDAX analyses were conducted to determine chemical, mineralogical and micro-structural changes in the aggregate and cement paste of samples. The experimental concrete deteriorations were performed using various chloride solutions (NaCl, CaCl, $MgCl_2$ and $Na_2SO_4$ solution. The experimental results were compared with the observation results in order to determine the effect of major elements in seawater on the deterioration. The alkalies in seawater appear to accelerate alkali-silica reaction (ASR). The gel formed by ASR is alkali-calcium-silica gel which known to cause severe expansion and cracking in concrete. Carbonation causes the formation of abundant less-cementitious calcite and weaken the cement paste. Progressive carbonation significantly affects on the composition and stability of some secondary minerals. Abundant gypsum generally occurs in concretes subjected to significant carbonation, but thaumasite ({$Ca_6/[Si(OH)_6]_2{\cdot}24H_2O$}${\cdot}[(SO_4)_2]{\cdot}[(CO_3))2]$) occurs as ettringite-thaumasite solid solution in concretes subjected to less significant carbonation. Experimentally, ettringite can be transformed to trichloroaluminate or decomposed by chloride ingress under controlled pH conditions. Mg ions in seawater cause cement paste deterioration by forming non-cementitious brucite and magnesium silicate hydrate (MSH).

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.6
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• pp.475-485
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• 2001

The presence of airborne particles in the earth atmosphere expert important controls on the global climate because of their effects on the radiative balance. However, there are major uncertainties associated with the direct and indirect radiative effects of aerosols. In addition, their physicochemical properties cannot only the decline of air quality but also damage human health. Airborne particles were collected by two different commercial air samples, high volume sampler(for TSP) and low volume sampler(for P $M_{10}$ ) at the campus of Kunsan National University during February to September, 2000. In most cases, TSP and P $M_{10}$ were sampled once a week for the duration of 24 hours from 9:00 a.m. In addition samples were collected more intenisve, when the yellow dust was expected. Each sample was analyzed for pH and major ions concentration (C $l^{[-10]}$ , S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ , N $a^{+}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$) by ion chromatography and atomic absorption spectrophotometry. Acidity (pH) of TSP and P $M_{10}$ ranged from 5.09 to 8.51 and from 6.22 to 7.54, respectively. The concentrations of airborne particles were found to satisfy both the short and long-term air quality standards during the sampling period. If the ratio of ionic concentrations originating from None sea salt(Nss) to sea salt(ss) in aerosol samples was concerned, it was found that the ionic concentrations from marine environment contributed dominantly in total mass concentration in the airborne particles. When seasonal trends were examined, the TSP concentrations in spring were higher than those of other seasons. It may result form frequent occurrences of yellow dust and during the spring season. The concentration ratio of P $M_{10}$ to TSP ranged from 0.78 to 1 during the sampling period. pH in the airborne particle was highest during spring, but the other seasons maintained almost same level. These results suggest that alkaline species in yellow dust can directly neutralize aerosol acidity. During spring season, yellow dust could be a positive factor that can defer the acidification of surface soil and water by neutralizing acidic aerosols in the atmosphere.osphere.

• Analytical Science and Technology
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• v.17 no.3
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• pp.230-239
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• 2004

Using our PM2.5 and PM10 concentration data obtained from Seoul and Busan during winter 2002, we conducted comparative analysis on the role of inorganic ions in constituting airborne particles in two distinctive urban areas. Whereas the mass concentration of fine particle was more significant in Seoul, no such pattern was found in Busan. In addition, when the major components were compared between different particle fractions and between different sites, clear pattern was apparent between those. Although the major components of fine particles were generally compatible each other ($NH{_4}^+$, $NO{_3}^-$, and NSSS), those of coarse fractions were clearly distinguished. Although anthropogenic signatures were still important in Seoul, the influence of oceanic sources was clear in coarse fraction of Busan ($Cl^-$ and $Na^+$). Detailed statistical analysis of our data consistently supports the importance of different source processes between particle modes and source processes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.202-210
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• 1983

In order to elucidate the taste compounds of Korean catfish, Parasilurus asotus, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals in the extracts of Korean catfish were analyzed, and then evaluated by sensory test of synthetic extract prepared on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, glycine was dominant occupying $25\%$ of total free amino acids. The other abundant free amino acids were lysine, taurine and alanine. Judging from the result of analysis of nucleotides, IMP was dominant showing about $70\%$ of total nucleotides while ATP, ADP, AMP, inosine and hypoxanthine were low in content. Among organic bases, total creatinine was abundant and its nitrogen content occupied more than $50\%$ of the total extractive nitrogen. The amount of betaine was 18mg/100g and trace amount of trimethylamine and trimethylamine oxide were detected. The main organic acids were succinic, butyric, propionic and valeric acid. On the other hand, oxalic, fumaric, maleic, tartaric and citric acids were analyzed in trace. As for the sugars, glucose was found to be the most abundant monosaccharide. Extremely small amounts of fructoae, inositol were also detected and ribose and arabinose were trace in content. $K^+,\;Na^+,\;PO_{4}^{3-}$ and $Cl^-$ were found to be the major ions and small amount of $Ca^{2+}$ were defected. The synthetic extract, prepared with about 40 pure chemicals based on the analytical data satisfactorily revealed the natural taste of the original extract except slight difference in meaty taste and mildness. From the results of omission test the major components which contribute to produce the taste were serine, IMP, succinic acid and $PO_{4}^{3-}$.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1345-1349
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• 1998

The flavor constituents and functionality of small kingfish were studied as affected by two stage enzyme hydrolysis (TSEH). Total free amino acid contents in water extract, autolytic extract and TSEH of small kingfish were 541.3 mg%, 8,245.3 mg% and 6,636.6 mg%, respectively. Major free amino acids in TSEH were hydroxyproline, glutamic acid, proline, leucine, phenylalanine, lysine, arginine. As for nucleotides and other bases, IMP, TMAO and total creatinine were principal components in TSEH. And the major inorganic ions in TSEH were Na, K, P, Cl and $PO_{4}$. Also TSEH of small kingfish revealed very higher Angiotensin-I converting enzyme inhibition effect than those of water and autolytic extract.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.95-103
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• 2009

To develop natural intermediate flavoring substances, optimal hydrolysis conditions and taste compounds for two step enzyme hydrolysate(TSEH) using Grass puffer(Takifugu niphobles) were investigated. The optimal conditions for TSEH method were revealed in temperature at $55^{\circ}C$ 3 hour digestion with Alcalase (pH 7.5) at the 1st step and 2 hour at $45^{\circ}C$ digestion with Flavourzyme(pH 6.0~6.5) at the 2nd step. TSEH method was superior to hot-water extraction on the aspect of yield, nitrogen contents and organoleptic taste quality such as umami and control of bitter taste formation. In taste active-components in Glass puffer TSEH, total free amino acid content was 4,502 mg%, major free amino acids were Pro, Leu, Lys, Hypro, Tau, Arg, Phe, Ala, Glu and Val in ordor. As for nucleotides, IMP(372 mg%) was the principal component and also contents of TMAO, total creatinine, and betaine were 43, 278 and 41 mg% in Glass puffer TSEH, respectively. The major inorganic ions in TSEH were Na(949 mg%), K(222 mg%), Cl(1,180 mg%) and $PO_4$(1,081 mg%).