• Korean Journal of Microbiology
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• v.45 no.4
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• pp.391-396
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• 2009

This study was carried out to investigate the changes in yeast cell number, organic acid and total acid during the fermentation and distribution processes for enhancement of preservation of Makgeolli. Organic acids, including lactic acid, succinic acid, malic acid and citric acid, were increased with fermentation time, while oxalic acid, phosphoric acid and acetic acid were not detected, respectively. Production of organic acids leaded to pH reduction in Makgeolli. In case of Makgeolli kept at $4^{\circ}C$, there was no change in organic acids until 20 days. On the other hand, when observing the change in organic acid of Makgeolli kept at $25^{\circ}C$, concentration of lactic acid was decreased, while citric acid was not detected from the beginning of storage. However, acetic acid was detected from 10th day and rapidly increased at the 25th day. Therefore, it is suggested that the current expiration date (10 days in a cooler) could be extended.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.96-99
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• 2003

The objective of this study was to evaluate the effects of various organic acids on microbial characteristics and Salmonella typhimurium in pork loins. Fresh pork loins were sprayed with various organic acids such as lactic acid, citric acid and acetic acid at various concentrations (0.5, 1, 1.5 and 2%). After spraying, the samples were packaged by HDPE film under air and stored at $4^{\circ}C$ for 14 days, and analyzed. Microbial deterioration of pork loins during the aerobic cold storage was delayed by organic acid spray. The bactericidal effect of acids increased with the increasing concentration. However, the inhibitory activity of organic acids during the storage varied with the kinds and concentrations of the acids. As for total plate counts, acetic acid was found to have the highest bactericidal activity, whereas citric acid was found to be the most inhibitory for coliform and S. typhimurium.

• Journal of Energy Engineering
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• v.13 no.3
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• pp.228-233
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• 2004

This paper reports production of low-molecular weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds with or without oxidant (H$_2$O$_2$). Organic acids such as acetic, formic, succinic and lactic acids were obtained. This result increased to 42mg/g dry waste fish entrails in the presence of H$_2$O$_2$. Experiments on glucose representing cellulosic wastes were also carried out, getting acetic acid of about 29mg/g glucose. Studies on temperature dependance of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general. results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.227-234
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• 1985

The present study was carried out for making clear the organic acids composition of some shellfishes and their boiled-dried products. Three species of shellfish such as top shell, hard clam and abalone were chosen as the experimental samples and analysed for their nonvolatile organic acids composition by gas liquid chromatography (GLC). Eight kinds of nonvolatile organic acid were identified in raw and boiled-dried top shell, major ones were succinic, malic and pyroglutamic acid. Out of nine kinds of nonvolatile acid was determined in raw and boiled-dried of hard clam, abundant ones were succinic, lactic and malic acid, And seven kinds of nonvolatile organic acid were detected in boiled-dried abalone while eight kinds in raw sample, abundant ones were succinic, lactic and pyroglutamic acid, respectively. In all samples, the total amount of nonvolatile organic acid was the most abundant in hard clam while the least in abalone, and the content of succinic acid was appeared as the most abundant one. In dried samples, the total amount of the nonvolatile organic acid was determined to be about half-decrease after the boiled-dried treatment of the raw samples, of which abalone showed the highest decreasing을 rate whereas hard clam was the lowest. In general, the decreasing rate of each acid was the higher in fumaric, malic and citric acid than in maleic, oxalic and succinic acid.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.129-133
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• 1993

The effect of different compositions of organic acids on the flavor profile of 10% sugar solution was investigated by the response surface methodology, and the results were used to evaluate the flavor characteristics of lactic acid fermented cereal beverages. A mixture of extruded rice flour (10%) and soymilk (7.8% dry matter) was fermented with Leuconostoc mesenteroides (Sikhae). Depending on the substrate pretreatments, for example, the malt or amylase digestion and the proteolytic enzyme hydrolysis, the sugar and organic acid composition of the product varied. The organic acid composition of the fermented beverages was in the ranges of 0.44-0.55% lactic acid, 0.05-0.09% acetic acid and 0.07-0.09% citric acid, while that of commercial apple juice was 1.59% malic acid and 0.49% acetic acid. The flavor profiles of fermented beverages added with 10% sucrose were compared to those of apple juice and a model mixture containing 0.48% citric acid, 0.39% lactic acid and 0.12% acetic acid in 10% sugar solution. The QDA diagram of fermented beverages approached to that of apple juice, when the substrate was digested by amylase but not by protease.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.186-192
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• 2004

This study was carried out to analyze the organic acids, polyphenols, pigments and fiber materials concentration with a different stalk position and grade of korean leaf tobaccos. Eight kinds of flue-cured leaf tobaccos which were different stalk position and grade were used for this study. Three kinds of major organic acids(citric, malic and oxalic), 2 kinds of polyphenols(chlorogenic acid and rutin), 3 kinds of pigments($\beta$-carotene, chlorophyll-a and chlorophyll-b), and 2 kinds of fiber components(pectin and lignin) were analyzed. All of these chemical components were changed with a different stalk position. When the citric acid, malic acid, $\beta-carotene$, chlorophyll-a, and lignin concentration were low in the middle stalk position and high in both bottom and upper position, oxalic acid and chlorogenic acid show the highest concentration in the middle stalk position. All of these chemical components also changed with a different grade of leaf tobaccos. As the citric acid, malic acid, $\beta-carotene$, chlorophyll-b, and lignin concentration decreased as the grade ascended, the oxalic acid and chlorogenic acid concentration increased as the grade ascended. This results assumed that the quality of korean leaf tobacco was directly proportional to oxalic acid and chlorogenic acid concentration but it was inversely proportional to citric acid, malic acid, $\beta-carotene$, chlorophyll-b and lignin concentration.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.403-405
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• 1985

The composition of fatty acids and organic acids in the fruits, stems, and roots of Acanthopanax were studied. The major fatty acids in the fruits, stems and roots were oleic, linoleic and palmitic acids and these composed about 86-98% of total fatty acids. However, there are great differences in content of the major fatty acids between varieties and each parts. Citric, malefic, succinic, malonic, fumaric and malic acids were identified in the fruits. Malic acid was the predaminant organic acid. There are great differences in individual content of the organic acids between varieties and each parts. Malonic and malefic acids were not detected in the stems and roots, respectively. Citric acid was most abundant organic acid parts. Total organic acid content in roots was very low compared to that of fruits and stems.

• Bulletin of the Korean Chemical Society
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• v.22 no.9
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• pp.1019-1022
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• 2001

Negatively charged functional organic molecules such as retinoic acid, ascorbic acid, indole acetic acid, citric acid, salicylic acid, acidic dye (indigo carmine, Food Blue 1) are intercalatively encapsulated by zinc basic salt (hydrozincite) and layered double hydroxide. Such functional organic-inorganic nanohybrids are realized via coprecipitation reaction involving simultaneous formation of layered inorganic lattice and intercalation of anionic species. The heterostructural nature of these nanohybrids, their particle morphology and textural characterizations are mainly discussed on the basis of Powder X-ray Diffraction and Field Emission Scanning Electron Microscopy results.

• Journal of Powder Materials
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• v.3 no.2
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• pp.112-119
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• 1996

Using rice husks pulverized by rotating knife cutter, the raw rice husk powder was solution treated by nitric and hydrochloric acids in order to separate phytolith from organic constituents. Because of the strong resistance of organic components of rice husk to acids, the raw powder had to be boiled in concentrated acids up to 300 min. By boiling in nitric acid for 60~120 min, all organic components were resolved while amorphous silica Powder of about 20 nm in size and of higher than 99.8% in purity was left behind. Inferior to the nitric acid, hydrochloric acid was not able to resolve organic component completely leaving unresolved matter of about 40% by weight even after 300 min of boiling. From the acid treatments and impurity analyses, it is considered that most of metallic elements in rice husks are combined to organic components that are easily soluble to acids.

• Fibers and Polymers
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• v.5 no.2
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• pp.110-116
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• 2004

Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH control in dye-bath-reuse system of acid dyes mixtures. The ability of pH control, levelness, dyeing properties and reproducibility in dye-bath-reuse system were investigated comparatively. Hydrolyzable organic esters showed higher exhaustion and color yield than ammonium sulphate. In addition, hydrolyzable organic ester exhibited very low conductivity less than 0.5 mS, while ammonium sulphate give high conductivity. However, we could not observe any difference in levelness of dyed samples between two kinds of acid donors in laboratory scale dyeing. Over 10 cycles of reuse, hydrolyzable organic esters showed higher reproducibility than ammonium sulphate. No deterioration of the color fastness and levelness occurs over 10 cycles of reuse.