• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.360-366
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• 2010

Doenjang (fermented soybean paste) is one of the korean traditional fermented soybean product which is consumed with cooked rice as a soup or paste. During the fermentation, soybean protein hydrolyzed into amino acids and various peptide, and various organic acids by mirobes related and enzymes produced by meju fermentation. Some commercial products locationally samples give more sour taste than normal due to abnormal fermentation which the reasons are not clear. Three samples that gave sour taste organoleptically were collected and analyzed their characteristics such as pH, moisture content, acidity and microbial counts. The pH of the sour sample were lower than the normal with higher acidity as pH 5.39 (normal) to pH 4.36 (S2) and 15.80 ml of(0.lN NaOH consumed) to 21.80 ml (S1) respectively. Salt and moisture contents were different with sour and normal Doenjang as 16.38% (normal) to 8.92% (S3) in salt and 55.94% (normal) to 49.34% (S1) in moisture content. Total viable counts were $4.1{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2), and $3.4{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2) in acid producing microbes at BCP plate. Yeast and mold were not detected. The composition of acids as mainly lactic acid and acetic acid of sour Doenjang. Total free amino acids content were lower the sour Doenjang than the normal.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.209-214
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• 1997

The canned fruit flesh of orange (Onju, Citrus unshi Marc.) was stored at $5^{\circ}C,\;15^{\circ}C,\;and{\;}30^{\circ}C$ for 4 months and the contents of sugar, organic acids and vitamin C of stored orange were investigated. The contents of reducing sugar of orange stored for 4 months slightly increased from 4.91% to $5.39{\sim}7.95%$ and decreased as the temperature rised. The sugar was composed of $6.63{\sim}18.09%$ sucrose, $3.86{\sim}9.12%$ glucose and $3.59{\sim}9.51%$ fructose. The content of sucrose used in manufacturing process was the highest and decreased as the temperature rised and as the storage period prolonged, whereas the contents of glucose and fructose increased as the storage period prolonged. The content of citric acid in the sample was the highest $(50.41{\sim}90.15\;mg%)$ among the-citric, malic, maleic, ${\alpha}-ketoglutaric$ and oxalic acids. The organic acids decreased as the temperature rised after storage for 4 months. The content of vitamin C was $8.28{\sim}14.29\;mg%$ and decreased most pronouncedly at $30^{\circ}C$ after storage. The color of the samples did not change significantly, but the degree of transparency, L was $20.41{\sim}23.01$ after storing the sample.

• Journal of the Korean Electrochemical Society
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• v.16 no.2
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• pp.74-80
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• 2013

We investigate the formation of nanoporous gold (NPG) surfaces by anodization in three carboxylic acid (formic acid, acetic acid, and propionic acid) solutions and the electrochemical oxidation of glucose at NPG surfaces. Among three carboxylic acids, formic acid provided the most efficient conditions for NPG formation towards glucose oxidation. The optimized conditions during anodization in formic acid for glucose oxidation were 5.0 V of applied potential and 4 hour of reaction time. Electrocatalytic activities for glucose oxidation at NPG surfaces prepared by anodization in carboxylic acids were examined under the absence and presence of chloride ions, which were compared to those observed at NPG prepared in oxalic acid solutions. The application NPG prepared by optimized anodization conditions in formic acid to the amperometric detection of glucose was demonstrated.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.213-219
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• 2003

The photochemical transformation of carbon monoxide in aqueous solution has been investigated at $25{\pm}0.1^{\circ}C$using ZnO as a photocatalyst. After irradiation of 253.7 nm UV light in the solution, carboxylation and carbonylation processes were carried out, and the formation of formic acid, oxalic acid, glyoxylic acid, formaldehyde and glyoxal was observed. The formation of the products depended on the pH values in the solution. The yield of formaldehyde and glyoxal increased in acidic solution whereas it decreased in basic solution. When the pH values in the solution increased above 11.5, the yield of formic acid increased rapidly. The initial quantum yields of the products were determined and the probable mechanisms for the reactions were presented on the basis of the products analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.42-49
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• 1988

In order to utilize sea mustard, Undaria pinnatifida, effectively. sea mustard jam was prepared by use of physical properties of polysaccharides, mainly alginic acid and then its chemical composition, nutritive qualifies and the stability of pigments were examined. Suitable processing condition for sea mustard jam was as fellows : as the first stage, fresh sea mustard was scalded for 20 sec at $85^{\circ}C$ and dried sea mustard was dipped for 20 min in cold water for rehydration, then both sea mustards were treated by draining and chopping. Next, after adding 4 fold of $0.5\%\;K_2HPO_4$ solution to weight of chopped sea mustards, the mixed solutions were agitated for 15 min at $95^{\circ}C$, and gelated sea mustards were filterated by pressing. Flow characteristics of those sea mustard jam were regarded mixed type having pseudoplastic type and yield stress. Judging from sensory evaluation, adding $0.375\%$ of saccharin, $2\%$ of sorbitol, $0.25\%$ of citric acid and $0.5\%$ of powder of roasted soybean to sea mustard jam were suitable for enhancing taste and flavor of product. Chemical composition of products were scarcely changed throughtout processing. Jam processed by fresh sea mustard was better than dried one in contents of chlorophyll and total carotenoid pigments. In fatty acid composition, polyenoic acids of $C_{18:3},\;C_{20:4},\;C_{20:5},\;C_{22:6}$ were held high contents as known to have lowering function of cholesterol contents. It was presumed that dominant contents in free amino acids such as lysine, alanine, glutamic acid and organic acids such as citric acid, oxalic acid, $\alpha-ketoglutaric$ acid, lactic acid and succinic acid held important role for the flavor of sea mustard jam.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.574-581
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• 2008

The optimum regeneration conditions for the regeneration of three way spent catalysts (TWCs), which were taken from automobiles with different driving conditions, were investigated to evaluate the suitability as alternative catalysts for removing VOCs. The spent catalysts were washed with five different acids ($HNO_3$, $H_2SO_4$, $C_2H_2O_4$, $C_6H_8O_7$, and $H_3PO_4$) to remove contaminants and examine the optimum conditions for recovering the catalytic activity. The physicochemical properties of spent and its regenerated TWCs were evaluated by using nitrogen adsorption-desorption isotherms, XRD, and ICP. The relative atomic ratios of contaminants and platinum group metals (PGMs) of the spent TWCs were greatly dependent on the placed positions. The main contaminants formed were lubricant oil additives and metallic components. Also, the regeneration treatment increased the PGMs ratio, BET surface area, and average pore diameter of TWCs. The catalytic activity results indicated that the spent TWCs have the possibility for removing VOCs. Moreover, the employed acid treatments greatly enhanced the catalytic activity of the spent TWCs. Especially, nitric and oxalic acids provided the most improvement in the catalytic behavior. The catalytic activities of the regenerated TWCs were significantly influenced by the containing platinum ratios rather than the removal ratios of contaminants and the changes in the structural properties offered by the acid treatments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1397-1405
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• 2009

This study was to investigate food components of Bigum spinach growing in Jeonnam Shinan. The samples used in this study were Pohang spinach of inland and jo-saeng, chung-saeng, man-saeng, chungman-saeng spinach of Bigum located on Jeonnam Shinan. We analyzed proximate composition, mineral content, germanium, organic acid, free sugar, vitamin A, C, and E contents. We conducted the sensory evaluation after blanching and color changes of before and after blanching of 5 kinds of spinach. The results were as follows: moisture and ash contents were significantly higher in Pohang spinach than Bigum spinach. Crude protein, carbohydrates and crude fiber contents were higher in Bigum spinach than Pohang spinach. In mineral contents, potassium and zinc contents were higher in Pohang spinach than Bigum spinach whereas calcium, iron, magnesium, manganese, sodium contents were higher in Bigum spinach than Pohang spinach. Germanium contents was 14.06$\sim$27.16 ppb in Bigum spinach whereas not detected in Pohang spinach. In organic acid contents, man-saeng and jo-saeng of Bigum spinach were high in oxalic acid, citric acid, malic acid and formic acid contents. Succinic acid and acetic acid contents were high in Pohang spinach. Almost all free sugars were higher in Bigum spinach, especially jo-saeng and man-saeng, than Pohang spinach except lactose. Vitamin A contents was similar with Pohang and Bigum spinach except chung-saeng but vitamin C and E contents were higher in Bigum spinach than Pohang spinach. Color L (light) after blanching was significantly higher in chungman-saeng than other spinaches. Color a (redness) was significantly lower in chung-saeng and man-saeng than others and chungman-saeng was significantly higher than others. Color b (yellowness) was low in man-saeng and high in jo-saeng of Bigum spinach. In case of sensory properties after blanching, taste, sweet, overall preference were significant higher in Bigum spinach except chung-saeng than Pohang spinach.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.383-389
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• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.51-62
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• 2009

This study was carried out development a new composting system to lower copper and zinc concentration in plg sludge compost and conduct an inquiry into the possibility of crop cultivation. The concentrations of nitrogen, phosphorus and pH averaged 4.4%, 6.3% and 7.57, respectively, which were higher concentrations than in commercial organic fertilizers, and the concentrations of copper and zinc averaged 805 and 1,704 mg/kg, respectively, which were beyond the heavy metal concentration limit in byproduct compost. Hydrated citric acid I lowered the concentrations of copper and zinc by 58% and 97%, respectively and hydrated oxalic acid II lowered the concentrations of copper and zinc by 48% and 56%, respectively in pig sludge compost. Lower concentrations of copper and zinc in pig sludge resulted from the enhanced hydrated-citric acid concentration in organic acid solution mixed with distilled water. The concentrations of copper and zinc were 330, and 41 mg/kg in the pig sludge treated with 100% hydrated citric acid. Agitation composting system stabilized the compost earlier than the stationary composting system, in which the stabilization condition was confirmed by higher temperature by $4^{\circ}C$ at highest temperature and 7 days earlier cooling down after highest temperature. The levels of germination index (G.I) 80 were obtained 15 and 20 days after composting in agitation and stationary composting system, respectively. The concentrations of copper and zinc were 2.4 and 4.26 mg/kg respectively in soils amended with pig sludge compost after removing process of heavy metals by citric acid, but 8.0 and 22.37 mg/kg, respectively in soils amended with Pig Sludge. The concentrations of heavy metals was highest in com cultivated in soils amended with pig sludge. The copper and zinc concentrations In corn leaves were 75.2 and 50.56 mg/kg respectively, which were 4 and 2 fold higher than the com cultivated in soils amended with pig sludge compost after heavy metal removing process by hydrated citric acid.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.389-397
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• 2016

In this study, ethanol was produced from a biomass hydrolysate that had been treated by electrodialysis (ED) and Amberlite XAD resin to remove fermentation inhibitors. Most of the acetic acid (95.6%) was removed during the ED process. Non-ionizable compounds such as total phenolic compounds, 5-hydroxymethyl furfural, and furfural were effectively removed by the XAD resin treatment. Ethanol production was improved when the ED-treated hydrolysate was treated with XAD-4 resin for a short reaction time. The highest ethanol production from ED-treated hydrolysate was $6.16g/{\ell}$ (after 72 h of fermentation) when the treatment with XAD-4 resin was for 5 min. Among the lignin-derived fermentation inhibitors tested, syringaldehyde in low concentrations (1 and 2 mM) in the hydrolysate increased ethanol production, whereas a high concentration (5 mM) inhibited the ethanol production process. A synthetic medium containing syringaldehyde and ferulic acid was prepared to investigate the synergistic effect of inhibitors on ethanol fermentation. Ethanol production decreased in the mixture of 1 mM syringaldehyde and 1 mM ferulic acid, implying that the effect of ferulic acid on ethanol fermentation is comparable to that of syringaldehyde.