• Analytical Science and Technology
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• v.23 no.4
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• pp.423-428
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• 2010

In this study, VOCs of black gel pen inks was screening to identify individual characteristic of gel pen inks. Detected VOCs was total 20 species(isopropylalcohol, 2-methyl-2-propanol, 2-butanone, hydrazinecarbothioamide, benzeneacetic acid (ethyl ester), benzeneacetic acid, dimethoxymethy-silane, 2,2-dimethoxybutane, tetrahydro-2-methyl-furan, 1,2-ethanediol, silicic acid (tetramethyl ester), 1,2-propanediol, propyleneglycol, 3-ethyl-3-hexanol, 1,1-dipropoxy-propane, 2-butoxy-ethanol, 2,2'-oxybisethanol, 1-butyl-benzene, 2-pyrrolidinone, 2-(2-butoxyethoxy)-ethanol). We detected 2,2-dimethoxybutane (3.02~47% ratio) and tetrahydro-2-methyl-furan (1.19~52.19% ratio), 1,2-ethanediol (52.83~95.84% ratio). In case of manufacturer, manufactured ink was able to discriminate between Japan and Korea by distinct characteristics (Japan: 1,2-ethanediol, 52.83~95.84%, Korea: 1,2-propanediol, 76.17~93.51%). The results of this study indicated that distinct characteristic about manufacturers and brands could make a classifring tool of inks for identification of between gel pen inks.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.790-799
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• 1997

The purpose of this study is to investigate the effects of yeast addition as starter on kimchi fermentation. The strains used as starter were Saccharomyces sp. YK-17 and Saccharomyces fermentati YK-19 isolated from kimchi, grew under anaerobic condition and low temperature, which showed the acid and base resistances. Chemical and microfloral changes, as well as the sensory properties of starter added kimchi during fermentation were compared with the control fermented without starter. The acidity of kimchi juice was lower and pH was higher in starter added kimchi than the control. Particularly addition of S. fermentati YK-19 prolonged the optimally fermented period (pH 4.0, acidity $0.6{\sim}0.8%$) up to more than 63%. The content of lactic acid, the major non-volatile organic acid in kimchi, was increased rapidly followed by S. sp. YK-17 and S. fermentati YK-19 group. The microfloral changes were found a little different among the samples. Among the microorganisms, Leuconostoc sp. and Lactobacillus sp. showed highest change, and Streptococcus sp. and Pediococcus sp. showed ralatively low change. The growth of Lactobacillus sp. which was the main acidifing microorganism was inhibited by starter addition, particularly by S. fermentati YK-19. The sensory characteristics of acidic and moldy flavor were significantly reduced by the addition, while fresh flavor was increased in starter added group.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.204-210
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• 2015

Makgeolli is made from rice or flour, yeast, and nuruk, a fermentation starter. The flavor of makgeolli is affected by sugars, amino acids, organic acids and volatile flavor compounds produced by various microorganisms. In this study, lactic acid bacteria (LAB) were isolated from unsterilized makgeolli samples collected from several provinces in Korea, and then later identified. Under anaerobic conditions, LAB density ranged from $5.0{\times}10^6$ to $1.5{\times}10^8CFU/mL$; yeast density ranged from $2.5{\times}10^7$ to $1.5{\times}10^8CFU/mL$. Of the LAB isolated from makgeolli, 1,126 were analyzed using restriction fragment length polymorphism (PCR-RFLP) analysis of 16S rRNA, which allowed for classification into five groups. Of the 1,126 LABs tested, 130 produced ${\gamma}$-aminobutyric acid (GABA).

• Journal of the Korean Society of Food Culture
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• v.19 no.1
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• pp.94-105
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• 2004

The biochemical components of Namcheondlggae, Miryangdlkkae 25, Boradlggae and Ipdlkkae 1 were measured. The samples were extracted with hot water, 60% acetone or 80% ethanol for screening physiological activity. The crude protein content (4.36%) was found in the Miryangdlkkae 25 and calcium content (497.5 mg%) was found in the Namcheondlggae among the tested 4 perilla loaves. Fructose was 30.86 mg% in the Namcheondlggae and free amino acids at all perilla leaves was detected seventeen. In Boradlggae, glutamic acid and alanine were 25.37 and 11.91 mg%. Totally nine non-volatile organic acids were also detected and the contents of malic acid and glutaric acid were 28.34 and 14.57 mg% in Boradlggae. The Miryangdlkkae 25 had the highest vitamin C amount which was 113.24 mg%. Angiotensin converting enzyme (ACE) inhibition activity of 60% acetone extract of Miryangdlkkae 25 was 39.20% when added as addition of 200 ppm level and xanthine oxidase inhibition activity of 80% ethanol extract of Boradlggae was 46.71%. Electron denoting activity of 60% acetone extract from Namcheohndlggae was the strongest inhibition activity as 98.19% when 200 ppm level of the sample extracts were added.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1258-1265
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• 2000

In oder to acquire microbial agents that can be utilized for control of aflatoxin produced by Aspergillus. flavus and Asp. parasiticus, antifungal bacteria were isolated. Antifungal bacteria was identified as Bacillus spp. based on morphology and physico-biochemical characteristics. Amount of aflatoxin $B_1$ from Doenjang(soybean paste) prepared with Asp. flavus, Asp. parasiticus, antifungal bacteria(Bacillus sp.), or mixture of Asp. flavus and Asp. parasiticus was 27.2 ppb, 30.3 ppb, 3.4 ppb, and 3.7 ppb, respectively. Aflatoxin $B_1$ was not detected from Doenjang(control) and Doenjang prepared with antifungal bacteria. Content and compositions of free sugars, fatty acid, organic acid and free amino acid in Doenjang prepared with Asp. flavus and Asp. parasiticus, antifungal bacteria and mixture of Asp. flavus and Asp. parasiticus were not significantly different. For volatile flavor compounds of Doenjang prepared with antifungal bacteria, 2-pentyl furan and butanoic acid were disappeared or reduced, while octadecene compounds were produced. However, those of Doenjang prepared with Asp. flavus or Asp. parasiticus and Doenjang(control) were not significantly different. These results suggested that the antifungal bacteria(Bacillus sp.) inhibited production of aflatoxin and that antifungal bacteria did not effect the quality of Doenjang.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.55-60
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• 2021

Fluorination was carried out to improve the adsorption performance of pitch-based activated carbon fibers (ACFs) onto acetic acid. Both plasma and direct gas fluorination were used for fluorination, and the acetic acid gas adsorption performance of fluorinated ACFs was investigated. X-ray photoelectron spectroscopy (XPS) is analyzed to determine the surface characteristics of ACFs, and the pore characteristics were analyzed by 77 K nitrogen adsorption. An adsorption performance was measured through gas chromatography, and it was confirmed that the breakthrough time of plasma fluorinated sample was 790 min and that the breakthrough time was delayed compared to that of using untreated one of 650 min. However, the breakthrough time of direct gas fluorinated sample was 390 min, indicating that the adsorption performance was inhibited. The plasma fluorinated ACFs showed an increase in the adsorption performance due to an electrostatic attraction between the acetic acid gas (CH3COOH) with the fluorine group introduced to the surface without changing its specific surface area. On the other hand, the specific surface area of the direct gas fluorinated ACFs decreased significantly up to 55%, and the physical adsorption effect on the acetic acid gas also reduced.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.541-546
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• 2009

The objectives of this study were to evaluate the physico-chemical and sensory characteristics of a Korean traditional alcoholic beverage (yakju) prepared using different nuruk (Korean-style koji) concentrations and yeasts such as the fusant FA776 and Saccharomyces cerevisiae KOY-1, respectively. The fusant FA776, which has alcohol-fermenting and starch-utilizing properties, was formed by Saccharomyces cerevisiae KOY-1 and Saccharomyces diastaticus KCTC1804. The fermentation trial was conducted in a 5 L lab-scale jar at $25^{\circ}C$. The maximum alcohol production of the K-100 and F-50 reached levels of 135.0 mg/mL and 119.4 mg/mL, respectively. The pH values were in a range of 4.3-4.5. Total acidity was in a range of 0.47-0.60%. Organic acids and amino acids were analyzed in order to evaluate variations in its composition and content via HPLC analysis. Organic acids including lactic acid, citric acid, malic acid, and pyruvic acid, and 16 kinds of amino acids, including aspartic acid, were detected in all treatments. K-100 showed the highest amino acid contents, whereas F-50 exhibited the lowest amino acid contents. Volatile flavor components such as phenylethyl alcohol, isoamyl alcohol, 2-methylthiophane, isobutyl alcohol, and ethyl succinate were detected as a major component in all treatments, as determined via gas chromatography. The results of our sensory evaluation demonstrated that Yakju fermented by the FA776 fusant yielded more favorable results than S. cerevisiae KOY-1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.41-51
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• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.146-158
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• 2010

In order to evaluate the characteristics of sediments and pollution by organic matter and metallic elements in intertidal sediments along the southwestern coast of Korea, we measured various geochemical parameters, including the mean grain size (Mz), water content (WC), ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and metallic elements (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, As), in intertidal surface sediments. The Mz of the surface sediments ranged from 2.1 to 8.3$\phi$, indicating that the surface sediments consist of various sedimentary facies, such as sand, slightly gravelly mud, sandy mud, and silt. The IL and COD in surface sediment ranged from 0.8 to 5.5% (mean $2.9\pm1.2%$) and from 3.9 to $13.8\;mgO_2/g{\cdot}dry$ (mean $8.5\pm2.6\;mgO_2/g{\cdot}dry$), respectively, which were lower than the values for surface sediment in areas near fish and shellfish farms or industrial complexes. No AVS was detected at any sampling station, despite various sedimentary facies. Most of metallic elements in surface sediments showed relatively good positive correlations with Mz and IL, which imply that the concentrations of metallic elements are mainly controlled by grain size and the organic matter content. The concentrations of metallic elements, except As, at some stations were considerably lower than those in the Sediment Quality Guideline (Effect Range Low, ERL) proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Similarly, the geoaccumulation index (Igeo) class indicated that pollution by metallic elements in intertidal surface sediment, except As, was moderate or non-existent. Our results imply that the intertidal surface sediments along the southwestern coast of Korea are not polluted by organic matter and metallic elements and are healthy for benthic organisms.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.