• Macromolecular Research
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• v.17 no.1
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• pp.14-18
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• 2009

The acceleration effect of various organic acids, such as methanesulfonic acid (MSA), ethanesulfonic acid (ESA), 4,4'-sulfonyldibenzoic acid (SDA), diphenylacetic acid (DPAA), and $\rho$-toluenesulfonic acid (TSA), on the rate of styrene bulk polymerization with 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) and benzoyl peroxide (BPO) was investigated. The addition of organic acids significantly accelerated the rate. Among these organic acids, DPAA showed an efficient rate-accelerating effect with living nature of polymerization. When DPAA was used as a rate-accelerating additive for TEMPO-mediated living free radical polymerization (LFRP), the rate of polymerization was dramatically enhanced, the linearity of reaction kinetics was successfully maintained, and the polydispersity was effectively controlled.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.552-560
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• 2017

This study aimed to evaluate the quality characteristics of Tteokgalbi with 1% (w/w) black rice bran only (T1), or with black rice bran and one of the following four types of organic acid: ascorbic acid (T2), citric acid (T3), tartaric acid (T4), or maleic acid (T5) as a substitute for caramel colorant. Tteokgalbi with only black rice bran showed the highest (p<0.05) values of moisture content and water holding capacity (WHC), while there were no significant differences in protein content, fat content, ash content, and thiobarbituric acid reactive substance (TBARS) values in treatments and controls (p>0.05). All the treated samples with any one of the four organic acids showed lower pH than controls (p<0.05). The lightness and redness of Tteokgalbi treated with any one of the four organic acids and black rice bran were higher than those of T1. The volatile basic nitrogen (VBN) values of T4 and T5 were higher than those of the other treatments (p<0.05). With regards to sensory characteristics, T1 and T2 showed overall acceptability similar to that of the controls (p>0.05). The results reported in this study show that Tteokgalbi with black rice bran and any one of the four organic acids listed above not only improved quality characteristics in cooking loss, WHC, lipid oxidation but also could successfully replace the synthetic caramel colorant. Overall, the most satisfactory results were obtained by adding black rice bran and ascorbic acid.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.3
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• pp.265-270
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• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.61-64
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• 1976

A survey of the free amino acids and organic acids in the shoot of Phyllostachys edulis was made by means of amino acid autoanalyzer and gas chromatograph. The results of the survey are summerized as follows. 1. Eighteen amino acids found in bamboo shoot were lysine, histidine, arginine, tryptophan, aspartic acid, glutamic acid, threonine, serine, proline, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine and phenylalanine, and an unknown was found. Serine showed the highest amount and more than about 44% of total free amino acids. 2. Oxalic acid was the major organic acid, and formic acid, acetic acid, maleic acid, succinic acid, fumaric acid, citric acid, tartaric acid and sorbic acid were determined, and two unknown were found.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.579-585
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• 2015

Following supplementation with organic acids (acetic, citric, and lactic acids), the pH of the alcohol mash changed from 4.2 control to 3.73-3.97 supplemented, the acidity from 5.06 to 8.13-9.98, and the alcohol content from 17.8 to 17.0-17.8%. Protease activity decreased owing to the pH change, and the total nitrogen content decreased by 13.1-36.9% following organic acid supplementation. Organic acid supplementation did not affect the distillation efficiency; however, thiobarbituric acid values in the crude distillate (40%) decreased 2.2-3.6 fold following supplementation with citric acid and lactic acid. The total isobutanol (B), isoamyl alcohol (A), and 1-propanol (P) contents in each soju (25%) supplemented with organic acid were 1,041.47, 979.50, and 961.48 ppm, respectively, which were higher than those in the control soju (935.27 ppm). The A/P, A/B, and B/P ratios of soju were altered and the acetaldehyde content decreased following supplementation with the organic acid.

• Resources Recycling
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• v.28 no.6
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• pp.36-45
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• 2019

The spent petroleum catalysts contain rare metals such as vanadium, nickel, molybdenum, and cobalt. Therefore, the leaching of these rare metals from spent petroleum catalysts by organic acid was investigated in the present study. The leaching efficiency of metals by organic acid was in the following order: oxalic acid > tartaric acid > citric acid > maleic acid > ascorbic acid. Among the organic acids employed in this work, oxalic acid can be considered to be superior to the other acids in terms of metals leaching efficiency. The effect of several leaching conditions such as temperature, acid concentration, pulp density, stirring speed, and reaction time on the leaching of metals was investigated. Vanadium and molybdenum were selectively dissolved by oxalic acid from the spent catalysts. The leaching kinetics of vanadium by oxalic acid was also investigated. An activation energy of 8.76 kJ/mol indicated that the leaching kinetics of vanadium by oxalic acid solution was controlled by mass transfer.

• Food Science and Preservation
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• v.6 no.2
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• pp.179-183
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• 1999

This study were comparison the quality characteristics of winter Chinese cabbage and investigation the physicochemical properties during Kimchi fermentation. External characteristics of three cultivars winter Chinese cabbage were compared, total weight of "Manpung" cultivar showed the heaviest in Chinese cabbages, but edible portion weight of "Seolwang" cultivar showed the heaviest in Chinese cabbages. Kimchi made of winter Chinese cabbage were fermented at 5$^{\circ}C$ for 40 days, of which pH, acidity, free sugar and organic acid were measured. The hardness of "Manpung" cultivar continued highly during the Kimchi fermentation at 5$^{\circ}C$. The pH and total acid in Kimchi fermentation, of the "Manpung" cultivar changed more than those of others. At the initial stage of Kimchi fermentation the major organic acid was citric acid, but lactic acid and acetic acid were increased rapidly during fermentation of Kimchi. The major organic acid of Kimchi fermented for 30 days was lactic acid, and the lactic acid contents of Kimchi prepared with "Manpung" cultivar was 6,796.6$\mu\textrm{g}$/g account for 69.6% of total organic acid.

• 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.

• Journal of Mushroom
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• v.2 no.3
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• pp.157-162
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• 2004

The objectives of this experiment were to study the growth and development of fruiting body of the two Ganoderma lucidum isolates on log of the soft wood Paraserianthes falcataria and the hard wood Shorea sp., and determination of organic germanium and crude ganoderic acid content of the fruiting body produced. The two Ganoderma lucidum isolates used were one Indonesian native (Indonesia isolate) and another isolate was purchased from Fungi Perfecti, USA (commercial isolate). The development and quality of the primordium and fruiting body of the mushroom, in general, were influenced by the isolates used. The types of wood, however, had no effect on the quality of the primordium and fruiting body produced. The Indonesian isolate produced better fruiting body compared to that of the commercial isolate. The development of fruiting body from primordium, however, was low for the two isolates tested. In general, only about one third of the primordium developed further into mature fruiting bodies, except for the commercial isolate grown on the soft wood medium in which more than 60% of the primordium developed into mature fruiting body. Apart from producing normal fruiting body, the commercial isolate also produced an abnormal one, which had a white mature pileus, whereas the normal one was brownish red. The organic germanium concentration of the fruiting body produced on the hard wood, in general, was higher than that of grown on the soft wood. The fruiting body from commercial isolate had higher organic germanium concentration compared to that of Indonesian isolate in both wood types. The two isolates used, however, had almost the same value of the crude ganoderic acid concentration in both types of wood tested. The Indonesian isolate had higher total yield of both organic germanium and crude ganoderic acid of the fruiting body produced compared to that of the commercial isolate.