• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.146-151
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• 2008

In this study, batch or semi-continuous reactions, introducing site-specific carboxylic acids in ${\beta}$-1,3-glucan structures, were performed to increase water solubility and gel forming ability, using TEMPO/hypobromite with or without NaBr as catalysts. Regio-selective carboxylic acid formations were determined with infrared (IR) and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopic analyses. The regio-selective reactions with and without NaBr gave oxidation yields of 92.5 and 85.6%, respectively, in the batch type, and yields of 93.9 and 86.4%, respectively, in the semi-continuous type. The reaction times in the batch and semi-continuous reactions without NaBr were delayed by 100 and 150%, respectively, as compared to those with NaBr. A combination of IR and $^{13}C$ NMR analyses were used to confirm the formation of carboxylic acids in ${\beta}$-1,3-glucan. From the batch reactions with and without NaBr, the water solubilities of oxidized products were 50.0 and 55.6%, respectively, and in the semi-continuous reactions they were 52.6 and 53.5%, respectively; while the water solubility of the native ${\beta}$-1,3-glucan was less than 1.0%. Finally, as compared to the native ${\beta}$-1,3-glucan, the gel forming ability of the reaction products was greatly increased irrespective of the presence of NaBr or the reaction type.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_2
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• pp.79-88
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• 2001

Humic acids react with chlorine to produce Trihalomethanes(THMs), known as carcinogens, during disinfection, the last stage in water purification. Currently, the removal of organic humic acids is considered the best approach to solve the problem of THM formation. Accordingly, the current study examined the adsorption of organic compounds of humic acids onto an inorganic carrier prepared from oyster shell waste. The adsorbent used was activated oyster shell powder(HAP) and silver ion-exchanged oyster shell powder(HAP-Ag), with CaCO$_3$ as the control. The adsorbates were phthalic acid, chelidamic acid, catechol, dodecylpyridinium chloride(DP), and 2-ethyl phenol(2-EP). The adsorption experiments were carried out in a batch shaker at $25^{\circ}C$ for 15 hours. The equilibrium concentration of the adsorbate solution was analyzed using a UV spectrophotometer and the data fitted to the Langmuir isotherm model. Since the solution pH values were found to be greater than the pKa values of the organic compounds used as adsorbates, the compounds apparently existed in ionic form. The adsorptive affinities of the organic acid and phenolic compounds varied depending on the interaction of electrostatic forces, ion exchange, and chelation. More carboxylic acids and catechol, rather than DP and 2-EP, were adsorbed onto HAP and HAP-Ag. HAP and HAP-Ag exhibited a greater adsorptive affinity for the organic compounds than CaCO$_3$, used as the control.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.78-84
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• 2019

Recently, bio-butanol is being promoted as environmentally friendly sustainable energy. However, some problems are still obstacle for commercialization of bio-butanol: the development of cheap biomass and enhancement of fermentation ratio and preparation of economical separation process for fermented products. In the conventional ABE biobutanol fermentation process, organic acids with acetone, butanol, and ethanol are produced. Therefore, it is necessary to study phase equilibrium data and mixture properties for the design and operation of separation process. However, there is lack of design data for organic acids except acetic acid contained system. In this study, therefore, binary solid-liquid equilibria (SLE) and mixture properties: the excess molar volumes ($V^E$), molar refraction deviation (${\Delta}R$) and deviation of viscosity (${\Delta}v$) at 298.15 for $C_3-C_6$ organic acid were reported. The experimental SLE data were correlated with the NRTL and UNIQUAC activity coefficient model with less than 0.5 K of root mean square deviation (RMSD). In addition, $V^E$, ${\Delta}R$ and ${\Delta}v$ for the same binary systems were satisfactorily fitted using the Redlich-Kister polynomial with less than ca. 0.004 standard deviation.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.825-835
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• 2020

Objective: The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C₇) and 120 days (C₁₂₀) of ripening. Methods: Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (zinc group, ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile. Results: The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones. Conclusion: The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes.

• Archives of Pharmacal Research
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• v.17 no.1
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• pp.26-30
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• 1994

Some ammonium oxalate soluble pectic fragments prepared from cultured cell wall of Ephycla distrahya elicited the accumulation of p-coumarocylamino acids (p-CAA) in E. distachya cultures while water soluble and alkali soluble fractions had no activity. Partial purification of the pectic fragments fraction using DEAE-cellulose chromatography afforded two active fractions (PS-I and PS-II) which were composed of mainly uronic acids (98-99 w/w %). They elicited the accumulation of p-CAA in an amount of 52-60 nmol per gram fresh weight of cultures. The acidic sugar compositions of PS-I and PS-II were found to be galacturonic acid and glucuronic acid by TLC analysis. They were supposed to act as endogenous elicitors of p-CAA accumulation. In order to investigate the effect of ethylene on p-CAA accumulation, Ethrel, which is known as ethylene generator, and ACC(1-aminocyclopropane-1-carboxylic acid), a direct precusor of ethylene biosynthesis, were added to the culture. However, they did not glycopeptide elicitor [(Con A-II)], either. Consequently, no relationships between ethylene and p-CAA accumulation were recognized. Several tentative elicitors were teted for their activity. Commercial yeast glucan, $CuCl_2$, laminarin and laminariheptaose had slight activity whereas ${\alpha}$-methylmannopyranoside and commercial yeast mannan had no elicitor activity. ${\alpha}$-methylmannopyranoside which has been known as a tentative inhibitor of glucan elicitor in Glycine max did not affect on the elicitor activity of Con A-II.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.449-455
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• 1986

Various polymer metal complexes have been synthesized from anhydrous $AlCl_3,\;FeCl_3,\;SbCl_5,\;SnCl_4\;and\;ZnCl_2$ with cation exchange resin in carbon disulfide solvent. The forms of the surfaces and sectioned beads of these polymer metal complexes have been observed using scanning electron probe microanalyzer. To examine the catalytic activity of polymer metal complexes, the esterification of various dibasic acids with alcohols have been carried out. Polymer metal complexes were found to be the effective catalyst for esterification of dibasic carboxylic acids.

• Membrane Journal
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• v.1 no.1
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• pp.44-54
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• 1991

Sulfonated polystyrene-divinylbenzene(PS-DVB) copolymer membranes were prepared using different diluents (toluene, cyclohexane, cyclohexanol), various diluent ratio and DVB contents. And initial fluxes of organic acids were investigated by varying pH and initial concentration. As a results, water content and ion-exchange capacity decreased with increasing DVB concetration. Among used diluents, cyclohexanol was the most efficient for building up the highest water content and ion-exchange capacity. In the experiment of permeation, carboxylic acid such as formic acid and acetic acid showed higher fluxes when pH was lower than pKa and amino add such as L-alanine showed minimum flux when pH was isoelectric value. The relationaship between initial fluxes and initial concentrations has been expressed by saturation kinetics.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.65-71
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• 1999

This study was carried out utilzing ability of sole carbon sources in soil microbial communities used by Biolog GN microplate. Cluster analysis showed that soil microbial cornmuties were categorized into three groups as forest, non-forest soil and naked soil of microbial group. Soil microbial commutites in a forest soil of Qirercus mongoIica was divided into another group microbial communites in Qirercus dendata vegetation soil and Pinus dnzsqlora vegetation soil by Multidimensional scaling(MDS). Generally, sole carbon utilzing abilties were higher in order of polymer, amino acids and carboxylic acids, but it was lower in amides substrates carbon group. From the result: it was supposed that metabolic diversity of microbial communities was corresponded to vegetation succession.

• Membrane Journal
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• v.7 no.3
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• pp.136-141
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• 1997

Humic acid has been extracted and purified from biologically nondegradable humic substances. Using the ion exchange capability of carboxylic acids which are the main component of the humic acids, a membrane was prepared with poly(viny1 alcohol). Its transport behavior of biologically active ions, $K^+$and $Na^+$, were investigated. The ion transport velocity increased with hydrogen ion concentration, especially, in the range of $10^-1$~$10^0$. The selectivity increased with increasing the concentrations of $K^{＋}$ and Na$^{＋}$, In particular, the transport velocity of $K^+$ increased twice compared to that of $Na^+$ at the 100 hydrogen ion concentration. In this regards, humic acid may be used as a new material for ion exchange membranes.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.274-280
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• 1997

The rates and stoichiometry of the reaction of gallane-trimethylamine with selected organic compounds containing representative functional groups were examined in tetrahydrofuran solution under standardized conditions (THF, 0 ℃). And its reducing characteristics were compared with those of aluminum hydride-triethylamine(AHTEA). The rate of hydrogen evolution from active hydrogen compounds varied considerably with the nature of the functional group and the structure of the hydrocarbon moiety. Alcohols, phenol, amines, thiols evolved hydrogen rapidly and quantitatively. Aldehydes and ketones were reduced moderately to the corresponding alcohols. Cinnamaldehyde was reduced to cinnamyl alcohol, which means that the conjugated double bond was not attacked by gallane-trimethylamine. Carboxylic acids, esters, and lactones were stable to the reagent under standard conditions. Acid chlorides also were rapidly reduced to the corresponding alcohols. Epoxides and halides were inert to the reagent. Caproamide and nitrile were stable to the reagent, whereas benzamide was rapidly reduced to benzylamine. Nitropropane, nitrobenzene and azoxybenzene were stable to the reagent, whereas azobenzene was reduced to 1,2-diphenylhydrazine. Oximes and pyridine N-oxide were reduced rapidly. Di-n-butyl disulfide and dimethyl sulfoxide were reduced only slowly, but diphenyl disulfide was reduced rapidly. Finally, sulfones and sulfonic acids were inert to the reagent under the reaction.