• New & Renewable Energy
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• v.18 no.2
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• pp.9-17
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• 2022

In this study, we used the Flux Balance Analysis (FBA) program to examine the behavior of hydrogen and organic acids according to seasonal changes in food wastewater collected from D city. The results showed that average hydrogen conversion rates in spring, summer, autumn, and winter were 1.06, 0.71, 1.21, and 1.13 mol H₂/mol of hexose_added, respectively, indicating a significantly lower hydrogen conversion rate in summer than in other seasons. This phenomenon is believed to occur because the carbohydrate concentration of the incoming food wastewater is low. In addition, Lactobacillus, the lactic acid-producing bacterium, was 21.3% in spring, 27.2% in summer, 17.5% in autumn, and 22.6% in winter. The most distinctive feature of the microbial community in summer was that 15.3% of the Ilyobacter was analyzed. It was confirmed that Ilyobacter, which is involved in the production of acetic acid and propionic acid, is closely associated with the tendency of increasing acetic acid and propionic acid and thus contributes to organic acid change. Clostridium, a hydrogen-producing bacterium, was 76.2%, 50.8%, 78.3%, and 74%, in spring, summer, autumn, and winter, respectively. It was confirmed that Clostridium dominates the microbial community by approximately 70% or more in all seasons except summer.

• Journal of the Korean Professional Engineers Association
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• v.17 no.3
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• pp.66-74
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• 1984

• Bulletin of the Korean Chemical Society
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• v.21 no.2
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• pp.238-240
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• 2000

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.1-8
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• 2016

The new movement towards green chemistry and renewable feedstocks makes microbial production of chemicals more competitive. Among the numerous chemicals, organic acids are more attractive targets for process development efforts in the renewable-based biorefinery industry. However, most of the production costs in microbial processes are higher than that in chemical processes, among which over 60% are generated by separation processes. Therefore, the research of separation and purification processes is important for a promising biorefinery industry. This review highlights the progress of recovery processes in the separation and purification of organic acids, including their advantages and disadvantages, current situation, and future prospects in terms of recovery yields and industrial application.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.654-658
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• 1996

Organic acid content and volatile aroma components in Jehotang were investigated. Organic acids were detceted by HPLC and it is composed of formic acid(0.07%). lactic acid(0.22%) acetic acid (0.32%), and citric acid(3.17%), the last of which is one of the noteworthy features of Jehotang contributing greatly to its sour flavor and taste. Among the 39 volatile aroma components, whose peaks were identified by GC/MSD, and whose structures were analyzable, 17 kinds of hydrocarbon(30.81%) one kind of aldehyde(7.18%), 2 kinds of ketone(4.79%), 8 kinds of terpene(25.96%) a variety of acids (16%), 2 kinds of alcohol(5.42%), 2 kinds of phenol(2.76%) and 3 kinds of the others(7.68%) were found. The hydrocarbons, terpenes and acids occupied 70% of the aroma components, contributing to and also composing the particular flavor of Jehotang. Extracted pigments from the Jehotang showed maximum light absorbance in the wave length ranges of 200~400nm, showing a high degree of light adsorption of yellow to red color.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.295-299
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• 2002

The esterification of alcohols with acetic acid, lactic acid and citric acid was carried out in batch during the second distillation. Effect of various parameters, e.g. pH of reactant base spirit, temperature of distillation, time of distillation were studied. The parameter of distillation temperature was modified by atmospheric distillation and pressure distillation. The pressure(1.9 atm.) distillation was used in order to react and distill at high temperature. Compared with the base spirit concentration, ethyl acetate, ethyl lactate and iso-amyl acetate in esterification distillate increased by 2,890%, 6,410% and 52%, respectively. Major factors of the esterification with organic acids in distilled spirit making were molecular weight of the organic acid and pH of reactant base spirit.

• Applied Biological Chemistry
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• v.8
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• pp.39-43
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• 1967

In the fermented mash of Takju made from different raw-materials the general components are det. ermined by chemical analysis and the organic acids, sugars are identified by paper chromatography method. The results are summarized as follows. 1. Alcohol content is the highest in the fermented mash made from starch. 2. Contents of organic acid in the fermented mash from rice are more than those in other raw materials including lactic acetic, succinic, fumaric, malic and The citric acid flavour of Takju mainly depends on the components of organic acids. 3. glucose, sucrose, fructose, maltose, raffinose, xylose are identified in the raw-materials and glucose, sucrose, fructose, xylose are found in the fermented mash. 4. In order to get good-flavour in the starch-fermented mash and flour-fermented mash as well as rice-fermented mash, there should be contented organis as much as rice-fermented mash.

• Applied Biological Chemistry
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• v.41 no.5
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• pp.395-398
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• 1998

To develop the natural antibacterial agents which don't have any toxicity against man, collected several species of medicinal plants were tested for their antibacterial activity and inhibition effect on organic acids production from Streptococcus mutans. Among the tested medicinal plants, methanol extracts and n-hexane fraction of Juniperus rigida S. et Z. had the comparatively strong activities. For example, strong antibacterial effect against S. mutans were showed in methanol extracts, n-hexane and chloroform fractions. Organic acids production were reduced to 89.3 and 90.8% of control in methanol extracts and n-hexane fraction treated concentration of 1 mg/ml, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.1-5
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• 2003

This study was carried out to prepare the depolymerized alginates by physical treatment processing with organic acids. The applied physical treatment methods were autoclaving, microwaving, and ultrasonicating, Among several physical depolymerization methods, autoclaving treatment was the most effective for hydrolyzing the alginate to low molecular compounds such as oligosaccharides. Citrate was most effective catalyst in hydrolyzing alginate to some oligosaccharides among organic acids. An acceptable autoclaving conditions for hydrolyzing alginate to oligosaccharides were to treat at $110^{\circ}C$ for 90 min and $120^{\circ}C$ for 60 min, respectively. The maximum depolymerization percentage produced by autoclaving was $56.8\%$. The depolymerized alginates prepared by autoclaving at $110^{\circ}C\;and\;120^{\circ}C$ has oligosaccharides of $3\~4 $and $7\~8$ species, respectively. The optimum condition for alginate oligosaccarides was autoclaving treatment with $0.5\%$ citrate solution at $120^{\circ}C$ for 90 min.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.43-50
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• 2005

We evaluated the nutritional composition of the siphon of the surf clam Tresus keenae in regard to the presence of nitrogenous [amino acids, nucleotides and their related compounds, total creatinine, betaine, trimethylamine oxide (TMAO), and trimethylamine (TMA)] and non­nitrogenous compounds (sugars and organic acids), lipid fatty-acid composition, and occurrence of minerals. The content of total free amino acids was 660.27 $\pm$ 7.94 mg/100 g, and the predominant amino acids were arginine, alanine, sarcosine, glycine, and glutamic acid. These amino acids accounted for $71\;\%$ of the total free amino acids. Among the nucleotides and their related compounds, inosine was the major component and comprised 40.38 $\pm$ 0.02 mg/100 g. Free amino acids were the largest contributor to total extracted nitrogen, comprising $49.94\%$, followed by total creatinine, betaine, nucleotides, and ammonia; the contribution of TMAO and TMA was small. For the non-nitrogenous compounds, malic acid, propionic acid, and succinic acid comprised the major portion of the ten kinds of organic acids detected, and the sugars found were glucose, maltose, and arabinose, which were estimated to be $147.0\pm7.15,\;34.45\pm1.09,\;and\;1.21\pm0.02\;mg/100\;g,$ respectively. The predominant minerals were Na and K, which comprised $11.43\pm1.06\;and\;9.46\pm1.02\;mg/100\;g,$ respectively. The major fatty acids were C22:6, C20:5, C23:0, C18:3, and C16:0 in the lipid fractions. The 23:0 level of glycolipid (GL) was the highest of any other lipid fraction. The amount of total polyunsaturated fatty acids (PUFA) in the lipid fractions was higher, ranging from $58.22\%\;in\;GL\;to\;77.1\%$ in phospholipid (PL), compared to the saturated and monounsaturated fatty acids. Of the n-3 fatty acids, C20:5 and C22:6 contributed $35.30-64.44\%$ of PUFA in the lipid fractions. The ratios of n-3 to n-6 PUFA in total lipid (TL), neutral lipid (NL), PL, and GL were 4.35, 4.26, 6.69, and 2.04, respectively.