• Culinary science and hospitality research
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• v.11 no.4 s.27
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• pp.1-13
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• 2005

This study analyzed the levels of N-nitrosamine(NA) and its precursors such as nitrite, nitrate, dimethylamine and trimethylamine in 10 samples of mollusk fish, 4 samples of crustacea fish and 11 samples of shellfish from fish distributed in a local markets. Mollusk fishes had nitrite concentrations ranging from non-detectable(ND) to 9.4 mg/kg, crustacea fishes ND to 8.8 mg/kg, and shellfishes ND to 4.3 mg/kg. Nitrates in mollusk fishes ranged from ND to 19.3 mg/kg, crustacea fishes 4.1 to 79.9 mg/kg, and shellfishes 1.5 to 61.9 mg/kg. DMK concentrations were 11.2 to 551.4 mg/100g in mollusk fishes, 44.4 to 79.9 mg/100g in crustacea fishes, and 1.3 to 5.9 mg/100g in shellfishes. TMA concentrations in mollusk fishes, crustacea fishes, and shellfishes were 10.3${\sim}$292.4 mg/100g, 35.5${\sim}$90.3 mg/100g, and 2.3${\sim}$17.1 mg/100g respectively. Only N-nitrosodimethylamine (NDMA) was detected for NA in fish distributed in local markets. NDMA contentrations ranged from ND to 41.4 ${\mu}g/kg$ in mollusk fishes, 3.0 to 47.3 ${\mu}g/kg$ in crustacea fishes, and 1.7 to 12.1 ${\mu}g/kg$ in shellfishes.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.333-339
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• 1997

The effects of kind of vegetables and of the kind and amounts of fermented fish sauce on the formation of nitrosamine (NA) during kimchi fermentation were investigated. Kimchies made of Chinese cabbage, cucumber, and radish with fermented shrimp, anchovy and liquid sauces were fermented at 4$^{\circ}C$ for 6 weeks and the changes in the content of nitrate, nitrite, trimethylamine (TMA), dimethylamine (DMA) and NA were studied. Nitrate content in kimchies made of Chinese cabbage, cucumber, and radish increased at the initial period of fermentation, but it decreased at the later period. Nitrite was not detected at the later period of kimchi fermentation. Overall, there have not been great changes in the contents of nitrite and nitrate. However, there have been considrable changes in the contents of TMA and DMA as fermentation progressed. Only nitrosodimethylamine (NDMA) at the level of 0.5~10.3 $\mu\textrm{g}$/kg was formed in three kinds of kimchies. More NDMA was formed in radish and cucumber kimchies than in Chinese cabbage kimchi. The pH was lowered faster in radish and cucumber kimchies than in Chinese cabbage kimchi. More NDMA was formed in Chinese cabbage kimchi made with fermented shrimp sauce than those with anchovy or liquid sauces. Shrimp sauce contained higher amount of DAM than anchovy and liquid sauces. The contents of NDMA tended to increase as the amount of shrimp sauce increased. The kind and amount of fermented fish sauce used for kimchi preparation may be an important factor affecting the formation of NDMA.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.45-51
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• 1988

To improve the individual packaging method and extend the shelf life of hair tail(Trichiurus japonicus), salted an unsalted hair tail chunk (cut in 8-10cm) were packaged in laminated plastic film bag(Nylon/PE: $20{\mu}m,\;12{\times}15cm$) filled with with free-$O_2$ absorber, in vacuum, and stored at 0 and/or $5^{\circ}C$. The other samples were packaged in plastic foam trays, overwraped with oxygen permeable film(control), and stored at same temperature. Volatile basic nitrogen (VBN), trimethylamine (TMA) and viable cell counts (VCC) were progressed with increase of storage time, but thiobarbituric acid (TBA) values decreased gradually after reaching at a maximum peak in 5-15 days. Judging from 4 chemical components, VBN was the most available component in quality judgement of hair tail chunk and its upper limiting content was 29 mg%. Regression equation for shelf life prediction of hair tail chunk with sensory evalution and VBN component was determined.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.39-49
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• 2007

In this study, the performance characteristics of solid phase microextraction (SPME) were investigated for three major odorous groups that consist of 10 individual compounds ([1] volatile organic compounds (VOC): benzene, toluene, p-xylene and styrene, [2] reduced sulfur compounds (RSC): hydrogen sulfide, methyl mercaptan, dimethylsulfide (DMS), dimethyldisulfide (DMDS), and carbon disulfide, and [3] amine: trimethylamine (TMA)). For the purpose of a comparative analysis, two types of SPME fiber ([1] polidimethylsiloxane/divinilbenzene (P/D) and [2] $Carboxen^{TM}$/polidimethylsiloxane (C/P)) were test ε d against each other for a series of standards prepared at different concentration levels (100, 200, and 500 ppb). To compare the analytical performance of each fiber, all standards were analyzed for the acquisition of calibration data sets for each compound. The results of P/D fiber generally showed that its calibration slope increased as a function of molecular weight across different VOCs; however, those of C/P fiber showed a fairly reversed trend. Besides, we confirmed that the application of SPME is limited to many sulfur compounds; only two compounds (DMS and DMDS) are sensitive enough to draw calibration results out of SPME. The calibration data for RSC show generally enhanced slop values for C/P relative to P/D fiber. However, in the case of TMA, we were not able to find a notable difference in their performance.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.219-229
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• 2016

Fatty liver is a common metabolic disorder of dairy cows during the transition period. Historically, the diagnosis of fatty liver has involved liver biopsy, biochemical or histological examination of liver specimens, and ultrasonographic imaging of the liver. However, more convenient and noninvasive methods would be beneficial for the diagnosis of fatty liver in dairy cows. The plasma metabolic profiles of dairy cows with fatty liver and normal (control) cows were investigated to identify new biomarkers using $^1H$ nuclear magnetic resonance. Compared with the control group, the primary differences in the fatty liver group included increases in ${\beta}$-hydroxybutyric acid, acetone, glycine, valine, trimethylamine-N-oxide, citrulline, and isobutyrate, and decreases in alanine, asparagine, glucose, ${\gamma}$-aminobutyric acid glycerol, and creatinine. This analysis revealed a global profile of endogenous metabolites, which may present potential biomarkers for the diagnosis of fatty liver in dairy cows.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.147-157
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• 2007

This study was carried out to investigate the characteristics of fourteen odor compounds from a total of 10 sampling sites in residential areas around Banwol-Sihwa industrial complex. The measurement data are analyzed and compared with sensation of odor unit. Only a hydrogen sulfide out of four sulfur compounds was quantified above the detection limit (0.06 ppb) in the residential area around Banwol industrial complex with leather companies and a sewage treatment plant. The concentrations of VOCs were higher than those measured from a big city, and styrene showed the relatively high concentration from all sampling sites ($2.1{\sim}37.8\;ppb$). In the case of carbonyl compounds, acetaldehyde was found most frequently with the mean of 3.97 ppb, and its concentration difference was not significant between Banwol and Sihwa industrial complex. Of the nitrogen compounds, ammonia was measured at the relatively high concentration from all the sampling sites ($12{\sim}707\;ppb$), and a trimethylamine was found at the odor threshold level (0.1 ppb). The concentrations of styrene and ammonia showed relatively seasonal variation, the concentration of styrene in summer was five times higher than that in autumn, the concentration of ammonia in autumn was two times higher than that in summer. However other odorous compounds did not show such strong seasonal variation. Odor-concentration relationship between odor unit and $H_{2}S$ concentrations from industrial sources was examined and used as odor sensation evaluation, and thus the neighbourhood odor complaints maybe caused during the four seasons from the results.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.627-636
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• 2016

The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.2
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• pp.122-131
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• 2012

This study was performed to examine the effects of Curcuma aromatica (CA) and orange rind on the quality and sensory score of flying fish $Cypselurus$ $agoo$ $agoo$ roe treated with electrolyzed water during frozen storage ($-18^{\circ}C$). The pH was decreased with increasing amounts of CA extract added to flying fish roe and during frozen storage. The flying fish roe treated with CA extract showed increased yellowness, as compared to flying fish roe with no CA extract added and untreated with electrolyzed water (untreated). The flying fish roe containing CA extract maintained greater hardness than did untreated flying fish roe. The volatile basic nitrogen and trimethylamine contents of treated flying fish roe were lower than those of untreated flying fish roe during frozen storage. The results of volatile organic compound tests showed that the contents of alcohol, acid and ketone compounds in flying fish roe treated with CA extract and orange rind were relatively decreased, but the limonene content of treated flying fish roe was increased compared to that of untreated flying fish roe. In sensory evaluation, flying fish roe containing 0.05 and 0.1% of CA were preferred over others. In conclusion, CA and orange rind increased the quality and sensory scores of flying fish roe treated with electrolyzed water.

• Food Science and Preservation
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• v.13 no.4
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• pp.519-523
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• 2006

In order to evaluate the possibility as cooking alcohol (Mirim) and tendering materials, kiwi wine and kiwi liqueur were added into braising mackerel and beef. The result showed that the crude proteolytic enzyme activity was high in kiwi wine and liqueur at 91.02 and 87.56% respectively. The trimethylamine (TMA) content in braising mackerel was 6.60, 4.80 and 5.79 mg% in control group, kiwi wine group and kiwi liqueur group, respectively. Sensory test of boiled mackerel gained high score in kiwi wine and kiwi liqueur stoups compared with control group The tendering effect in beef was high in kiwi wine and kiwi liqueur groups compared with control group. Thus, kiwi wine and kiwi liqueur could be used as cooking alcohol.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.33-39
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• 2009

This study was conducted to evaluate production of complex odor and 12 specific odorous compounds in a pilot-scale (capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each raw material was mixed with seed material and operated for two periods (1st : 50 days, 2nd : 60days). During composting, the temperature hit $90{\sim}95^{\circ}C$ after every mixing in both periods. Therefore, it was concluded that increasing temperature also saves the time which required for composting and high reduction of organics and water contents. The primary odorous compounds were ammonia, methyl mercaltan, dimethyl disulfide and trimethylamine. The concentration of the primary compounds and complex odor during the operation were higher than those on final day and most compounds did not exceed the allowable exhaust standard for odor. Also, it was found that optimal mixing time and control of high temperature are the most important parameters for odor control in ultra thermophilic aerobic composting.