• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.875-881
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• 2001

For beverage using Citrus reticulata, Ostrea gigas and medicinal herbs were formulated by determining optimum ratio of mixing to several other ingredients, the results of element and amino acid analyses with Ostrea gigas and Citrus reticulata were as follow. The mineral contents of Ca and Na in Ostrea gigas were 18.8 ppm and highest as 23.8 ppm, respectively. The content of aspartic acid in Citrus reticulata was 14290.431 pmol, and 8 kinds of essential amino acid contained. In the sensory test of beverage using Citrus reticulata, Ostrea gigas, the sensory score(color, taste, flavor) were the best on mixing ratio of Citrus 1g, Amomum 0.25g, Pueraria 0.5g, Ostrea I2g, citric acid 1g, sodium benzoate 0.5g, aspartic acid 0.5g, raw sugar 90g. The general analyses were similar 3 kinds of sample.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.245-250
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• 1985

In order to increase citric acid productivity. several attempts were made; isolation and characterization of the mutant strain produced citric acid in a high yield, citric acid fermentation in a medium containing relatively higher amount of glucose and citric acid production by the use of semicontinuous ceil recycle system. By the treatment of Candide lipolytica S-109 with NTG, a mutant J-24 was selected as the highest producer of citric acid among the strains formed larger CaCO$_3$ lytic zone. it produced 72g/1 citric acid in 10％ glucose medium. Because mutant J-24 produced 85g/l citric acid and showed 53％ yield in 16％ glucose medium, several factors were adjusted to increase the yield in 16％ glucose medium. 0.8-1.0$\times$10$^{-3}$ P/C ratio, 0.15％ urea, 0.25％ yeast extract were suitable at citric acid production in 16％ glucose medium. Under this condition, J-24 strain produced 93g/l citric acid and showed 58％ yield. Semicontinuous cell recycle system was used to protons the effective production phase, to minimize the product inhibition and to shorten the lag phase. The productivity of semicontinuous cell recycle system was 0.79g/l h while that of batch system was 0.53g/l.h

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.549-558
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• 2016

Purpose: In this study, we aimed to minimize quality degradation of concentrated blueberry puree by thermal treatment at $90^{\circ}C$ for 5 min, with citric acid (CA) and acidic sodium metaphosphate (ASM) as pH modifiers. Methods: The color values, redness a, anthocyanin contents, DPPH radical scavenging, elastase inhibition and tyrosinase inhibition activities were evaluated for quality parameters of concentrated blueberry puree. Results: The highest values of color value, redness a, anthocyanin contents, DPPH radical scavenging, elastase inhibition and tyrosinase inhibition activities were 1% CA+0.5% ASM followed by 1% CA and control. The quality parameters of concentrated blueberry puree were significantly different between control and 1% CA+0.5% ASM treatment (p<0.05). Conclusion: During thermal treatment, quality degradation of concentrated blueberry puree was reduced by 1% CA+0.5% ASM treatment, which is expected for new acidulants.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.733-738
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• 2013

Sediment contains a high fraction of organic matter, high buffering capacity, and a large portion of fine grained particles such as silt and clay, which are major barriers to remove heavy metals from sediments. In this study, a lab-scale electrokinetic (EK) technique was applied to remove heavy metals effectively from marine sediment at a constant voltage gradient of 2 V/cm. A concentration of 0.1 M of ethylenediaminetetraacetic acid (EDTA), citric acid (CA), $HNO_3$, and HCl were circulated in the cathode, and tap water was circulated in the anode. CA extracted 92.4% of Ni, 96.1% of Cu, 97.1% of Zn, and 88.1% of Pb from marine sediment. A higher voltage gradient enhanced the transport of citrate and EDTA into the sediment and, therefore, increased metal extraction from the marine sediment through a complexation reaction between metals and the chelates. Based on these results, the electrokinetic process using a high voltage gradient with EDTA and CA might be useful to extract heavy metals from marine sediment.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.14-20
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• 1991

Changes in fruit quality and some components of Unshiu orange(Citrus Unshiu Marc. Hayashi) stored at $2^{\circ}C$ in air or a controlled atmosphere(CA, $O_2$ 10%, $CO_2$ 2%) for 111 days were studied. The incidence of rot fruits was higher in air(12.7%) than in CA condition(3.9%). The appearance of the fruits was better in CA condition than in air. There was no significant difference in the weight loss of whole fruits between both storage conditions. The ratio of the flesh weight In whole fruits under CA condition was slightly lower than those in air until 62 days of storage, while it showed no rapid decrease in the later period of storage. Under both storage conditions, the Brix in the flesh increased in the early Period of storage and then decreased slowly, while the free acid contents decreased gradually during storage. In comparison with the fruits stored in air, those under CA condition showed lower total sugar content. The sugar in the flesh of the fruits is composed of sucrose, fructose and glucose. The content of total sugar as well as each sugar showed no distinct difference under both storage conditions. In the flesh of the fruits, citric acid comprised about 90% of the organic acid and malic acid the second abundant acid. During storage, the contents of citric, malic and oxalic acid decreased. Significant difference in the decreasing rate of total organic acid between both stnrage conditions was not found. From the above results, it might be considered that CA could be applied lot the storage of Unshiu orange grown on Cheju

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.923-928
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• 2016

To increase the consumption of head-type kimchi cabbage leaves as fresh food ingredients, the physicochemical composition was investigated depending on leaf parts. Kimchi cabbage leaves were divided into three portions, such as outer (L1), mid (L2), and inner (L3), and their proximate compositions were determined along with dietary fiber, free sugar, organic acid, free amino acid, and mineral contents. Contents of moisture, crude protein, and crude fat were highest in L1, whereas contents of crude ash and carbohydrate were highest in L3 (P<0.05). Calories ranged 24.5~26.5 kcal/100 g with no significant difference among leaf parts, and dietary fiber content of L1 was highest (P<0.05). Fructose, glucose, and sucrose contents were highest in L3 (P<0.05). Citric acid, malic acid, and succinic acid were detected, and contents of citric acid and malic acid were highest in L3, in contrast, succinic acid was highest in L1 (P<0.05). Glutamic acid, constituting over 30% of the total free amino acid contents, was highest in L3, whereas ${\gamma}-aminobutyric$ acid contents were highest in L1 (P<0.05). K, Na, Ca, and Mg were the major minerals in head-type kimchi cabbage, and their contents showed no significant differences (P<0.05). It can be proposed that marketing of head-type kimchi cabbage as a fresh-cut vegetable could be enhanced due to the different quality characteristics of its leaf parts.

• Korean Journal of Food Science and Technology
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• v.5 no.4
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• pp.215-223
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• 1973

A potent citric acid producing strain was selected by an extensive screening test of the yeasts isolated from the various sources. These experiments were conducted to identify the selected strain and investigate the cultural conditions for citric acid production. The results obtained were as fellows: 1. The selected strain of yeast was identified to Hansenula anomala var. anomala by a taxnoomic study of Lodder. 2. The optimum conditions for citric acid production in the basal medium containing 10% glucose were: temperature $30^{\circ}C$, the concentration of $CaCO_3$ 3% and the velocity of oscillation 110 oscills/min. 3. As a nitrogen source ol the basal medium $NH_4Cl(0.1%)$ was the most effective for citric acid production. Organic nitrogen sources such as peptone were adequate for growth of the strain but not for citric acid production. 4. The most effective concentration of glucose was 10% in yield ratio of citric acid from sugar. 5. The addition of defatted rape seed, defatted perilla or defatted rice bran to the medium was effective for citric acid production. When 5% extract solution of defatted rape seed was added, the citric acid production was increased as much as 40% as compared with the case of adding yeast extract(0.2%). 6. The most effective concentration of $KH_2PO_4$ and $MgSO_4{\cdot}7H_2O$ in the medium(for citric acid Production) was 0.05% and 0.025% respectively. 7. Under the optimum cultural conditions, the growth of the strain was continued up to 5 days and the increase of citric acid production was continued up to 6 days, showing the yield ratio of 46% to glucose.

• Resources Recycling
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• v.17 no.5
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• pp.44-51
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• 2008

The removal of minor elements such as Na, Ca and Fe has been performed from domestic aluminum hydroxide of 99.7% purity with organic acids. Oxalic and citric acid were used as the leaching agent, respectively and aluminum hydroxides of different particle size were also employed for the purification with organic acid leaching. Fine grinding of aluminum hydroxide has been tested using ball mills and leaching characteristics of each element have also been examined in terms of leaching parameters such as temperature, acid concentration, and solid density. As a result, it was found that oxalic acid showed higher leaching efficiency than citric acid in the concentration range of 0.1 to 1.0 mole/l and leaching amount of each element was also increased with the acid concentration and reaction temperature. It was observed that about 45% of Na was leached out during ball milling process which implied that the majority of Na contained in aluminum hydroxide was water soluble compound.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.210-216
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• 2021

Pollution of agricultural soil by alkaline salts, such as Na₂CO₃, is a critical and long-lasting problem in cultivable land. The aim of the study was to examine the putative role of citric acid (CA) in alleviating Na₂CO₃-stress in alfalfa. In this study, Na₂CO₃ significantly induced leaf chlorosis, inhibited plant growth and photosynthesis related parameters, increased hydrogen peroxide (H₂O₂) and reduced major antioxidant enzymes (SOD, CAD, APX) in alfalfa. However, the presence of CA these negative effects of Na₂CO₃-stress largely recovered. Interestingly, expression of antioxidant and ion transporter genes (Fe-SOD, CAT, APX, DHAR and NHX1) involved in Reactive oxygen species (ROS) homeostasis and oxidative stress tolerance in alfalfa. These findings suggest that CA-mediated Na₂CO₃ stress alleviation is an ecofriendly approach that would be useful to local farmer for alfalfa and other forage crop cultivation in alkaline soils.

• Journal of the Korean Home Economics Association
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• v.34 no.4
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• pp.403-414
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• 1996

The softening of the femented vegetables and the fruits was resulted from the degradation of pectin substances, cellulose, hemicellulose by polygalacturonase(PG), pectinesterase(PE), Cx-cellulase, $\beta$-galctosidase. The conversion of insoluble pectin to soluble pectin in cell wall-middle lamella was a major factor in the changes of firmness. Ca2+ was substantially increased firmness. However, Ca2+ could be removed from cell wall by chelating agents such as oxalic acid and citric acid. And Ca2+ was replaced with Na+ by ion exchange reaction. Ca2+ deficient tissue was vulnerable to attack by PG. Preheating treatment and Ca2+ addition is most effective in inhibiting the vegetable food softening and in increasing middle lamella-cell wall regidity, which PE activation by preheating treatment and Ca2+ addition could created more anionic carboxyl groups for cationic materials binding such as Ca2+ and chitosan and for polypectategel formation. Excessive demethylation by PE was associated with loosening of middle lamella cell wall components and softening.