• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.48-53
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• 1995

Changes in the contents of sugar, organic acid, free amino acid and uncleic acid-related compounds of leaf mustard-Kimchi during fermentation at 5~7$^{\circ}C$ were investigated. The leaf mustard-Kimchi was formulated with 4kg leaf mustard, 120g garlic, 80g ginger, 540ml salted anchovies, 1kg green onion, 200g red pepper powder, 200g ground red pepper, 60g whole sesame and 600ml glutinous rice paste. Changes in pH and acidity were relatively slow. Major free sugars were glucose(0.13%) and maltose(0.42%), and residual sugars(0.03-0.04%) were also detected after 32 days of fermentation. Major free amino acids containing more than 26.5mg% were proline, glutamic acid, alanine and histidine. Contents of total free amino acids increased from 244.8 to 397.2mg% by 24 days of fermentation. Of non-volatile organic acid, lactic acid was the most abundant(119.3mg%), and its content increased markedly after 10 days of fermentation. Other organic acids(below 53.1mg%) observed were malic, oxalic and citric acid. Contents of nucleic acid-related compounds were high in the order of hypoxanthine(22.8mg%), IMP(8.3mg%) and GMP(6.9mg%). Hypoxanthine content increased by 10 days(27.3mg%) and decreased thereafter, while the others decreased gradually during the overall period of fermentation.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.75-81
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• 2010

In order to investigate the effects of different milling degrees on the quality of glutinous rice wines, the physicochemical properties and volatile compounds of various wines were evaluated. Sample wines prepared from glutinous rice with 90, 80, and 70% milling yields were analyzed for ethanol, pH, total acids, amino acids, soluble solids, coloring degree, UV absorbance, reducing sugars, organic acids, free sugars and volatile compounds. After fermentation for 17 days, ethanol contents in the wines ranged from 15.2 to 15.85%, while total acid levels ranged from 0.31 to 0.35%. The amino acid contents in four samples ranged from 0.63 to 0.73%, while soluble solid contents ranged from 11.4 to $13.1^{\circ}Bx$. The wine prepared from glutinous rice with a 30% degree of milling showed the highest coloring degree, UV absorbance and reducing sugar content among four samples. Furthermore, this wine had the highest levels of malic acid and acetic acid, while the glutinous rice wine prepared from rice with a 0% degree of milling had the highest levels of succinic acid and lactic acid. In all the glutinous rice wines tested, the most abundant free sugar was glucose followed by maltose. With increasing degree of milling, the alcohol, amino acid and organic acid contents of the glutinous rice wines decreased, whereas soluble solids, coloring degree, UV absorbance, reducing sugar and free sugar contents increased. Volatile compounds were identified using GC-MSD, and thirty-nine esters, seven alcohols, six acids, one aldehyde, four alkanes, one alkene and two miscellaneous compounds were identified in the glutinous rice wines. Using relative peak area, it was determined that other than ethyl alcohol, hexadecanoic acid ethyl ester was the major component and was primarily found in the range of 11.566-18.437%. Succinic acid diethyl ester and isoamyl laurate decreased with an increasing degree of milling, whereas hexanoic acid ethyl ester and 2-octenoic acid ethyl ester increased. Overall, it was shown that different milling degrees greatly affected the physicochemical and volatile characteristics of the glutinous rice wines.

• Preventive Nutrition and Food Science
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• v.18 no.3
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• pp.203-209
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• 2013

The objective of the present study was to evaluate the physicochemical and microbial properties of the Korean traditional rice wine Makgeolli, supplemented with banana during 6 day fermentation. The alcohol contents of the control and banana Makgeolli were 17.0 and 16.5%, respectively. The pH values decreased while total acidity, total soluble solids, and color values increased throughout the fermentation process. An increase in microorganism counts throughout the 6-day fermentation period was noted in all samples. The major free sugar and organic acid detected in all samples were glucose and succinic acid, respectively. There were 39 volatile compounds detected in the control and banana Makgeolli. The major ester detected was ethyl acetate (20.037 and 22.604% for the control and banana Makgeolli, respectively). The major alcohol compounds detected were 3-methylbutanol (20.933%) and 3-methyl-1-butanol (34.325%) in the control. 2-mtehyl-1-propanol (22.289%) and 3-methyl-1-butanol (39.851%) were the highest alcohol compounds detected in the banana Makgeolli.

• Food Science and Preservation
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• v.7 no.2
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• pp.189-194
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• 2000

To study the potential of the Zanthoxylum schinifolium and Z. piperitum leaves, as raw materials for functional food and medicine, apart from male and female, chemical components were carried out. Among general components of sancho and chopi leaves, moisture and crude protein were higher sancho leaf than chopi leaf, but total sugar and crude fat were higher chopi leaf than sancho leaf and the components of major minerals were K, Ca, Mg and Na. Among free sugars, glucose(0.24% and 0.21%) and sucrose(0.19% and 0.27%) were the highest contents in sancho and chopi leaves(male and female), respectively. The organic acid were isolation and identification as malic acid and citric acid, citric acid is higher than malic acid. The total amino acid of sancho and chopi leaves contained proline and glutamic acid in male and female sancho and female chopi leaves, glutamic acid and aspartic acid in male chopi leaf highly in order. The fatty acid contents of four samples were high 15.16%, 9.76%, 8.78% and 9.29% of linolenic acid, respectively. Among many volatile compounds, limonene(13.25% and 19.16%) and citronellal(34.37% and 29.66%) were predominant flavor compounds in sancho and chopi leaves(male and female), respectively.

• The Korean Journal of Food And Nutrition
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• v.13 no.5
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• pp.453-459
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• 2000

In order to promote the utilization of Rubus coreanum as functional food, and its physicochemical properties and volatile flavor were examined. The contents of chemical compounds showed 5.39% of moisture, 17.3% of total sugars, 8.6% of reducing sugars, 4.5% of crude ash, 3.9% of crude fiber, 10.6% of crude protein and 1.7% of crude fat and that of free sugars was 1.52% of sucrose, 3.98% of fructose, 1.24% of glucose. Among organic acid was 10.2% of citric acid, 6.29% of oxalic acid and 1.94% of malic acid. The highest component of free amino acids was 1,260.3mg of aspartic acid, 1,054.3mg of glutamic acid, respectively. And that of minerals was 38,789ppm of K. A total of 52 volatile flavor components (11 alcohols, 13 acids, 20 carbonyls, 5 hydrocabons, 3 esters) were identified in the Rubus coreanum, respectively. The major volatile flavor components of Rubus coreanum were 3.78% of linalool in alcohols, 14.40% of caproic acid in acids, 2.99% of 2-hydroxy-4-methoxyacetophenone in carbonyls, 1.59% of aromadendrene in hydrocabons and 0.43% of methyl palmitate in esters.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.599-608
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• 2017

This study investigated the quality characteristics and volatile flavor components of aronia wine (Aronia melanocarpa (0~100%)). After 12 days of fermentation, the alcohol contents of aronia wines ranged between 9.0~12.0%. The pH level and total acidity of aronia wines were 3.20~3.68 and 0.57~0.76 g/100 mL, respectively. The organic acid analysis of wine containing 100% aronia, revealed malic acid content at 3.70 mg/mL, followed by tartaric acid, lactic acid, and citric acid. As the aronia content increased, both the total polyphenol content and the antioxidant activity (the DPPH radical scavenging activity) also significantly increased. The total polyphenol content was the highest in the wine with 100% aronia (461.33 mg%), and the antioxidant activity showed the highest values in the wine with 100% aronia (91.91%). Volatile flavor component analysis of aronia wines identified 8 alcohols, 12 esters, 4 ketones, and 7 other compounds. In the sensory evaluation, the color, flavor, and taste of wine with 20% aronia showed higher values than other aronia wines. Based on the results of the present study, we suggest that 20% aronia is most beneficial in improving the quality as well as sensory characteristics of the wine.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.191-196
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• 2007

Indoor air differs from outdoor atmosphere since it contains chemical and physical contaminants from building materials. This study deals with the biological effects of volatile organic compounds (VOCs) released from synthetic fiber carpet materials. One group of Tradescantia inflorescence was exposed to VOCs from the carpet sample in the environmental test chamber, while the other inflorescence group was exposed to a TO-14 standard gas mixture (1 ppm) for comparison. After the exposure, VOCs from the carpet were analysed by the desorber/GC/MS method, and micronuclei in the pollen mother cells of Tradescantia were scored under a microscope $({\times}400)$ to evaluate the genotocixicity induced by the exposure to VOCs. The chemical analysis confirmed that a total of 12 VOCs were released from the carpet materials, among which stylene $(71.9{\mu}g\;m^{-3})$ and toluene $(49.6{\mu}g\;m^{-3})$ were in the highest concentration. Twenty four hours of exposure to VOCs from the carpet in the environmental test chamber resulted in a micronucleus frequency as high as $7.73{\pm}0.75MCN$ per 100 tetrads, which was similar to that induced after exposure to the TO-14 standard gas mixture (1 ppm) for 4 hours. Meanwhile, two hours of exposure to the standard gas mixture did not cause a significant increase in the genotoxicity compared to the spontaneous micronucleus frequency. This result indicates that exposure for a long time to the air contaminated with VOCs from the carpet materials causes a genotoxic effect. The biological-chemical combination analyses in the study proved to be an effective tool for monitoring the indoor air contaminants.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.153-162
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• 2020

Objectives: 3D printing technologies have become widely developed and are increasingly being used for a variety of purposes. Recently, the evaluation of 3D printing operations has been conducted through chamber test studies, and actual workplace studies have yet to be completed. Therefore, the objective of this study was to determine the emission of volatile organic compounds(VOCs), metals, and particles from printing operations at a workplace. This included monitoring conducted at a commercial 3D printing service workplace where the processes involved material extrusion, material jetting, binder jetting, vat photo polymerization, and powder bed fusion. Methods: Area samples were collected with using a Tenax TA tube for VOC emission and MCE filter for metals in the workplace. For particle monitoring, Mini Particle Samplers(MPS) were also placed in the printer, indoor work area, and outdoor area. The objective was to analyze and identify particles' size, morphology, and chemical composition using transmission electron microscopy with energy dispersive spectroscopy(TEM-EDS) in the workplace. Results: The monitoring revealed that the concentration of VOCs and metals generated during the 3D printing process was low. However, it also revealed that within the 3D printing area, the highest concentration of total volatile organic compounds(TVOC) was 4,164 ppb at the vat photopolymerization 3D printing workplace, and the lowest was 148 ppb at the material extrusion 3D printing workplace. For the metals monitoring, chromium, which, is carcinogenic for humans, was detected in the workplace. As a characteristic of the particles, nano-sized particles were also found during the monitoring, but most of them were agglomerated with large and small particles. Conclusions: Based on the monitoring conducted at the commercial 3D printing operation, the results revealed that the concentration of VOCs and metals in the workplace were within Korea's occupational exposure limits. However, due to the emission of nano-sized particles during 3D printing operations, it was recommended that the exposure to VOCs and metals in the workplace should be minimized out of concern for workers' health. It was also shown that the characteristics of particles emitted from 3D printing operations may spread widely within an indoor workplace.

• Journal of Animal Science and Technology
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• v.63 no.4
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• pp.790-798
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• 2021

The objective of this study was evaluation of pig behavior changes related to temperature, relative humidity, volatile organic compounds (VOCs), and illuminance. A total of 24 growing pigs ([Yorkshire × Landrace] × Duroc) were used in the experiment. A sensor was installed at a height of 0.5 m in the center of the pig house. In experiment 1, temperature was changed every four days to 18℃ (T1), 22℃ (T2), 26℃ (T3), and then 30℃ (T4). In experiment 2, relative humidity was adjusted to 45% (low humidity [LH]), 60% (middle humidity [MH]), and then 75% (high humidity [HH]) for four days. In experiment 3, after cleaning the pig house just before experiment, only minimal ventilation was provided. VOCs and pig behaviors were observed for 7 days without cleaning the pig house. In experiment 4, three light bulbs of 40 W (470 lumens / 45 lx; low illuminance [LI]), 75 W (1,055 lumens / 103 lx; middle illuminance [MI]), and 100 W (1,521 lumens / 146 lx; high illuminance [HI]) were used for four days each. Pig behavior analysis was performed for following criteria : Feed intake, Standing, Lying, Sitting, Drink water, Rooting, Posture transition (lying-standing), Posture transition (standing-lying), Wallowing, and Biting. In experiment 1, feed intake time was lower (p < 0.05) for the T3 than other treatment groups. Standing time was highest (p < 0.05) for the T1 and lowest (p < 0.05) for the T3. Lying time was shorter (p < 0.05) in T1 and T2 compared to T3 and T4. Drinking frequency was higher (p < 0.05) for the T4 than other treatment groups. In experiment 2, the frequency of rooting and wallowing increased (p < 0.05) with increasing humidity. LH showed the lowest (p < 0.05) rooting frequency and HH showed the highest (p < 0.05) rooting frequency. In experiment 3, VOCs concentration did not (p > 0.05) change pig behavior. In experiment 4, lying time was the longest (p < 0.05) at LI and shortest (p < 0.05) at HI. Therefore, pig behavior is heavily influenced by the environment, especially temperature and humidity. However, correlation between pig behavior to VOCs and illuminance seems to be needed more research.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.25-35
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• 1989

To prepare a new type of fish sauce from skipjack scrap, it was examined the effect of koji on the sauce flavor, conditions of low salt fish sauce processing and the changes of taste com-pounds during its fermentation. To prepare the skipjack scrap sauce, chopped skipjack head paste was mixed with $6.6\%$ skipjack viscera, $26.9\%$ koji, $71\%$ of $25\%$ brine, $13.3\%$ salt and $7.6\%$ glucose, and fermented at $25\pm4^{\circ}C$ for 90 days. The same process was also carried out to prepare the low salt skipjack scrap sauce adding $7.6\%$ sorbitol, $0.3\%$ lactic acid and $9.8\%$ ethyl alcohol instead of $13.3\%$ salt. The major free amino acids in the products were glutamic acid, Iysine, valine, phenylalanine, alanine, leucine and isoleucine at 90 days of fermentation. And the contents of total free amino acids in both products were 3,307mg/00m1, 3,637.1mg/100m1 at 90 days of fermentation. The predominating non-volatile organic acids showed in the products were lactic acid, succinic acid, pyroglutamic acid, which were $90\%$ over contents of the total non-volatile organic acids. Total non-volatile organic acid contents in both products were 1,002.1mg/100ml, 1,312.9mg/100m1 at 90 days of fermentation. During fermentation of sauce, ADP, AMP and IMP were decreased, while inosine and hypoxanthine were increased. The major taste compounds of the products were rove진ed free amino acids and non-volatile organic acids. The nucleotides and their related compounds, total creatinine, betaine, TAMO and sugar were seemed to be having an auxiliary role in taste of those products. Fishy odor in skipjack scrap sauce can be improved by adding koji. And the low salt skipjack scrap sauce ($9.12\%$ of salt contents) can be prepared by the replacement of a part of salt with sorbitol, lactic acid and ethyl alcohol. From the results of sensory evaluation and chemical experiments, the skipjack scrap sauce products supposed to be at least equal to the sold soy sauce on the market in quality.