• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.67-74
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• 1982

The effect of various pH levels, temperatures. organic acids, inorganic salts, metal ions on the stability of the anthocyanins pigment (pH 3.7) from the juice of raspberries were investigated. Initial absorption of total anthocyanin was decreased as pH increased from 1.0 to 7.0. Total amount of anthocyanin reached the highest at pH 3.7 and least at pH 7.0. The total anthocyanin content decreased rapidly with the increasing temperature. Many organic acids were found to enrich and stabilize the color density at 520nm in anthocyanin solution (pH 3.7). The hyperchromic effect of saturated n-carboxylic acid increased in the following order; formic acid> acetic acid>n-butyric acid>propionic acid. On the polycarboxylic acid, especially, malic acid showed 550$\sim$930% higher than control group. On the inorganic salts (0.5M), sodium perchlorate had the most hyperchromic effect and followed by sodium sulfate>sodium chloride>sodium phosphate, monobasic. Among the metal ions, both aluminium ion and cupric ion much more accelerated the anthocyanins degradation as compared with other metal ions.

• Korean journal of food and cookery science
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• v.6 no.1
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• pp.1-8
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• 1990

To study the most optimum condition of Dongchimi, the various Dongchimi distinct from the amount of salt, the temperature of fermentation and the ratio of radish to water were examed by sensory evaluation. Also, the content of volatile organic acids and nonvolatile organic acids were investigated by GC, the content of sulfur compounds by GC/MS. Volatile organic acids were identified with those butyl esters and nonvolatile organic acids were done with those TMS derivatives. Sulfur compounds and those decomposed products were extracted by steam distillation In results, the most optimum conditions ware salt 2.4% fermented temperature $4^{\circ}C$, ratio 1:1.5. Volatile organic acids detected were formic, acetic acid, and the amounts were effected by saltness. Nonvolatile organic acids detected were lactio, malio, fumario, tartario acid. Lactic acid was thought to effect overall eating quality. Sulfur compounds were almost the isothiocyanate groups in raw radish, which little in fermented Dongchimi.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.753-761
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• 2016

Liquid-liquid extraction (LLE) can be used for the recovery of acetic acid from black liquor prior to bioethanol fermentation. Recovery of value-added chemicals such as acetic-, formic- and lactic acid using LLE from Kraft black liquor was studied. Acetic acid and formic acid have been reported to be strong inhibitors in fermentation. The study elucidates the effect of three reaction parameters: pH (0.5~3.5), temperature ($25{\sim}65^{\circ}C$), and reaction time (24~48 min). Extraction performance using tri-n-octylphosphine oxide as the extractant was evaluated. The maximum acetic acid concentration achieved from hydrolyzates was 69.87% at $25^{\circ}C$, pH= 0.5, and 36 min. Factorial design was used to study the effects of pH, temperature, and reaction time on the maximum inhibitor extraction yield after LLE. The maximum potential extraction yield of acetic acid was 70.4% at $25.8^{\circ}C$, pH=0.6 and 37.2 min residence time.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.221-227
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• 1996

This study was performed to analyze general components such as, organic acids, alcohols and minerals In persimmon vinegar made with quick fermented using deteriorated sweet persimmon and four commercial vinegars (rice vinegar, apple vinegar, brewed vinegar, traditional persimmon vinegar) purchased In local markets for quality evaluation. The pH and total acidity of all vinegars were in the range of 2.02-3.02 and 4.62-9.78%, respectively The pH of quick fermented persimmon vinegar (A) was relatively higher than that of others. Acidity was the highest in brewed vinegar. Total sugar content was in the range of 0.45-6.43%. These contents were high In were high In traditional persimmon vinegar wherase low in brewed vinegar. Total nitrogen and amino-nitrogen were in the range of 0.025-0.046% and 0.015-0.029%. Organic acids were identified as acetic acid, citric acid, tartaric acid malic acid, succinic acid, formic acid and oxalic acid. While major minerals of all vinegars were Mg, Ca, and Na, minor minerals were Zn, Cu, Mn and Fe.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1408-1411
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• 2009

This paper describes organic acid-based wet chemical etching behaviors of amorphous Ga-doped zinc oxide (GZO) thin film sputter-deposited at low temperature (room temperature). Wet etch parameters such as etching time, temperature, and etchant concentration are investigated for formic and citric acid etchants, and their effects on the etch rate, etch residue and the feature of edge line are compared.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.481-490
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• 2007

An experiment was conducted to investigate the effects of dietary supplementation of MOS, lectin and organic acid mixture(Organic acid F, Organic acid G) on the egg production, egg quality, profile of leukocytes and erythrocytes, small intestinal microflora and immune response in laying hens. A total of 900 Hy-line BrownⓇ laying hens of 48 wks old were assigned to one of the following 6 dietary treatments:control(C), C+AvillamycinⓇ 6ppm, C+MOS 250ppm, C+lectin 12.5ppm, C+Organic acid F(formic acid 35.4%, formate 34.6%, potassium 30.0%) 0.3% and C+0rgarnic acid G(fumaric acid 23%, calcium formate 14%, potassium sorbate 5%, calcium propionate 7%) 0.06%. Each treatment was replicated five times with thirty birds per replicate, housed in 2 bird cages. Feeding trial lasted for 6 wks under 16 hours lighting regimen. All supplemental groups were higher than the control in 6 wks hen-day and hen-housed egg production showing the highest with MOS treatment(P<0.05). Soft & broken egg productions were lower in supplemental groups than in the control except lectin treatment(P<0.05). Eggyolk color of supplemental groups was higher than that of the control except Organic acid G treatment(P<0.05). The values of RBC, HB, MCHC were highest in lectin treatment and lowest in MOS treatment(P<0.05). The numbers of intestinal microflora were not significantly different among the treatments. Serum IgG levels of all supplemental groups were higher than those of the control(P<0.05). In conclusion, for supplementation of antibiotics, immune modulators and organic acid mixture improved production parameters in general. Among the supplements, MOS showed the best performance in egg production and eggyolk color.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.31-36
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• 2001

Optimal operation in chromatography is needed to save operation time and the solvent used in multiple chromatographic runs. To this end, many simulation studies of chromatography process have been performed. The relationship between the distribution coefficient and the ionic strength is important in gradient elution ion chromatography. Experimental runs and computer simulations were carried out under linear gradient elution condition in order to compare the experiments and the simulation. Experiments were performed with formic acid under isocratic conditions to determine the simulation equation parameters. Computer simulation was based on three equations which related distribution with ionic strength as follows; K=${\alpha}$I(sup)-${\beta}$, K=A+BI+Cl$^2$and K=y(sub)0+A$_1$$.$e(sup)(-I/m$_1$). The effects of gradient slope on the chromatograms are discussed, and good agreement between the experimental and the simulated results is shown.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.133-139
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• 2001

Generally $PbTiO_3$ is manufactured in a form of thin films which is useful for the application of infrared sensors and non-volatile memory devices. Moreover $PbTiO_3$ has a characteristic of adsorption for organic acid as well as electronic property. Organic acid adsorption properties of $PbTiO_3$ powder prepared by sol-gel method was compared with the powder purchased from Aldrich Co. Crystallization and particle size of $PbTiO_3$ are influenced by process variables, such as dilution of sol solution, catalysis, calcination temperature, calcination time, etc. As the size of $PbTiO_3$ power decreased until several nanometers, adsorption of acetic acid and formic acid was increased 1.5-fold and 1.2-fold respectively.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.190-196
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• 2021

Desulfurization reaction in a bubble type reactor was carried out by adding three organic acids such as acetic acid, lactic acid, and antic acid to investigate the enhancement of the desulfurization performance of low-grade limestone. Desulfurization of limestone slurry without organic acids initiated to degrade at pH 5.2 or less, whereas organic acid-added limestone slurry exhibited a stable efficiency in the initial desulfurization with slurry pH ranging 4.2~4.5. At slurry pH below 4, the desulfurization performance of limestone slurry with addition of organic acids may be related to the amount of anions produced by dissociation of the organic acids. When limestone slurry had a large amount of anions, a rapid decrease in buffer capacity of slurry pH did not occur. These results were due to the acidity and dissociation of organic acids. The desulfurization performance of low-grade limestone slurry increased in the order of acetic acid (2.6%) < lactic acid (6.4%) < formic acid (16.7%).

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.266-269
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• 1993

The production of free non-volatile and volatile organic acids in Kimchi during fermentations at 30, 20 and $5^{\circ}C$, were determined by gas chromatography. The order in the amount of non-volatile organic acid, soon after preparation, was malic, citric, tartaric, pyroglutamic, oxalic, lactic, succinic and ${\alpha}-ketoglutaric$ acids. The major non-volatile acids at the optimum ripening time were malic, tartaric, citric and lactic acids, and as the temperature was lowered, the amount of lactic, succinic, oxalic, pyroglutamic and fumaric acids increased, while that of malic and tartaric acids decreased. The order in the amount of volatile acids at the beginning was acetic, butyric, propionic and formic acids. Among these acids, acetic acid was significantly increased in its amount during fermentation and the Kimchi fermented at low temperature produced more acetic acid than that fermented at high temperature.