• Title/Summary/Keyword: Oxalic Acid

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Changes in Quality Characteristics of Traditional Kochujang Prepared with Apple and Persimmon during Fermentation (사과.감과실을 첨가한 고추장의 숙성중 성분 변화)

  • 정용진;서지형;이기동;이명희;윤성란
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.4
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    • pp.575-581
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    • 2000
  • Quality characteristics of kochujang prepared with appleand persimmon were investigated during 14 weeks of fermentation. The water activity decreased slightly during fermentation and was higher in kochujang (I) prepared with apple than in kochujang (II) prepared with presimmon. The reducing sugar contents increased from 10.95% in kochujang (I) and 10.30% in kochujang (II) to 16.68, 19.14% after 10 weeks of fermentation, respectively. The free sugar contents in kochujang (I) were maltose 10.55, glucose 8.47 and fructose, 3.02% after 12 weeks of fermentation. The free sugar content in kochujang (II) were maltose 10.55, glucose 21.65, glucose 8.71 and fructose 2.98 after 6 weeks of fermentation. The major free sugar in kochujang (I) and (II) was maltose. The organic acids detected in kochujangs were citric, malic, lactic and oxalic acids. The contents of citric acid and malic acid were higher than other acids in both kochujangs. The contents of total free amino acids were 187.59~420.94 mg% in kochujang (I) and 154.67~316.93 mg% in kochujang (II). The contents of aspartic acid, proline and glutamic acid were high in kochujang (I) and (II).

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Chemical Equilibria of Lanthanide {Ln(III)=Pr, Sm, Gd, Dy}-Macrocyclic Complexes with Auxiliary Ligands in $CH_3OH$(Part III); Study of the Coordination of Nitrogen-or Oxygen-Containing Bases ($CH_3OH$ 용매에서 란탄족 원소 {Ln(III)=Pr, Sm, Gd, Dy}-거대고리 착물과 보조리간드 간의 화학평형(제3보); 두자리 리간드(주게원자:N혹은 O)를 중심으로 고찰)

  • Byun, Jong-Chul;Park, Yu-Chul;Han, Chung-Hun
    • Journal of the Korean Chemical Society
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    • v.44 no.2
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    • pp.95-101
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    • 2000
  • Macroacyclic transition metal complexes such as $Cu(H_2L[A]).H_2O$, $Cu(H_2L[B]).H_2O$, CuFe(L[A]($NO_3$).$4H_2O$, CuFe(L[B])($NO_3$).$4H_2O$, [$CuGd(H_2L[A])(NO_3)_2](NO_3).2CH_3OH$, [CuGd($H_2L$[B])($NO_3)_2$]($NO_3).2CH_3OH were prepared from the corresponding hexadentate compartmental ligands, $H_4L[A]$ and $H_4L[B]$, which were obtained by the condensation of 2-hydroxy-3-hydroxymethy1-5-methyIbenzaldehyde(HHNNB) and ethylenediamine or l,3-diaminopropane. Ln-macrocyclic([20]DOTA) complexes,[Ln([20]DOTA)($NO_3)(H_2O)$]($NO_3$)2.$xH_2O${Ln(III)=Pr, Sm, Gd, Dy, which had been synthesized from 2,6-diformyl-p-cresol(DFPC), was placed in methanol for 2 days, and [Ln([20] DOTA)($NO_3)(CH_3OH)]^{2+}$ was formed The equilibrium constants (k) for the substitution of coordinated $CH_3OH$ in the Ln-[20]DOTA complexes by various bidentate auxiliary ligands, $L_a$(=o-phenylenediamine,1,10-phenanthroline, ethylenediamine,oxalicacid, malonic acid, acethylacetone) were determined by spectroscopic method at $25^{\circ}C$ and 0.1M $NaClO_4$.The pKa of auxiliary ligands is in the order of o-phenylenediamine < 1,10-phenanthroline < ethylene-diamine, oxalic acid < malonic acid < acethylacetone. However, the equilibrium constant(K) has shown thetrend of ethyleneiamine < 1,10-phenanthroline < o-phenylenediamine, acethylacetone < malonic acid < oxalic acid.

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Changes in Organic acid, Mineral, Color, Curcumin and Bitter Substance of Curcuma longa L. and Curcuma atomatica Salib According to Picking Time (울금 품종과 채취시기별 유기산, 무기질, 색도, Curcumin 및 쓴맛의 변화)

  • Kang, Seong-Koo
    • Food Science and Preservation
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    • v.14 no.6
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    • pp.633-638
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    • 2007
  • Changes in organic acid, mineral, color, curcumin and bitter taste of Curcuma longa L. (autumn woolgeom in Korean) and Curcuma atomatica Salib (spring woolgeom) were investigated according to picking time. Oxalic and lactic acid were gradually increased, and then malic acid and malonic acid were decreased by extending the picking time. Total organic acid was increased by extending the picking time and then decreased after January of the coming year. Minerals were increased by extending the picking time and decreased slightly after the coming year. Hunter color index, L, a and b, was increased by extending the picking time. Contents of curcumin in spring woolgeom was slowly increased by extending the picking time and autumn woolgeom was $1.8{\sim}2.5$ times higher than spring woolgeom. Intensity of bitter taste in two woolgeoms were not different by picking time and extracting solvents. Bitterness of spring woolgeom was strong as compared to autumn woolgeom.

A Study on the Dissolution of Aluminum Hydroxide with Mineral and Organic Acid (Aluminum Hydroxide의 유무기산(有無機酸)에 의한 용해특성(溶解特性) 연구(硏究))

  • Lee, Hwa-Young
    • Resources Recycling
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    • v.18 no.2
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    • pp.56-61
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    • 2009
  • The dissolution of domestic aluminum hydroxide of 99.7% purity has been performed with mineral and organic acid prior to the synthesis of aluminum compounds from aluminum solution. Mean particle size of aluminum hydroxide used in the work was $14.4{\mu}m$, $22.9{\mu}m$ and $62.3{\mu}m$, respectively and the effect of reaction temperature, concentration of acid and reaction time on the dissolution of aluminum hydroxide has been examined. As a result, the dissolution of aluminum hydroxide was increased with the concentration of HCl and more than 70% dissolution was obtained with 5 mole/l HCl at $70^{\circ}C$ for reaction time of 4 hr. As far as the dissolution of aluminum hydroxide with sulfuric acid was concerned, it was found that the optimum concentration of sulfuric acid was about 6 mole/l for the effective dissolution of aluminum hydroxide. When oxalic acid was used for the dissolution of aluminum hydroxide, nearly complete dissolution could be obtained by the dissolution for 16 hr with 1.0 mole/l oxalic acid at $90^{\circ}C$.

Studies on the Organic Acid in Some Species of Marine Alage (해조류의 유기산에 관한 연구)

  • 김영진
    • Journal of the Korean Home Economics Association
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    • v.9 no.2
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    • pp.30-33
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    • 1971
  • 1. The present paper deals with the composition of organic acid in Porphyra tenera, roasted Porphyra tenera and Undaria pinnatifida. 2. There are little differences in the composition of organic acids among three of them, Porphyra tenera, roasted Porphyra tenera and Ucdaria pinnatifida. Butyric, propionic, acetic, fumaric, succinic, lactic, oxalic, malic, citric and unknown two acids were identifled by silica gel colcumn chromatography. 3. All of volatile organic acid, namely butyric, propionic and acetic acid in Porphyra tenera were decreased during the raosting.

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Effect of rice mash on the quality characteristics of strawberry jam (쌀당화액 첨가량에 따른 딸기잼의 품질특성)

  • Kim, Mi Jin;Kim, Jin Sook;Chang, Young Eun
    • Food Science and Preservation
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    • v.22 no.6
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    • pp.817-822
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    • 2015
  • This study investigated the physical, textural, and sensory properties of strawberry jam with different amounts (0%, 14%, and 21%) of added rice mash. The soluble solids, pH, and total acidity values of the samples were found to be in the range of $53.00{\sim}65.33^{\circ}Brix$, 4.11~4.20 and 0.66~0.80%, respectively. Soluble solids and total acidity decreased significantly as the amount of rice mash was increased. The L-value, a-value, and b-value increased on increasing the amount of rice mash (p<0.05). The glucose contents of the samples ranged from 3.86 g to 4.13 g. The fructose, sucrose, and maltose contents significantly decreased (p<0.05). The organic acid content was measured and it was found that, oxalic acid was not in the control sample (0% rice mash). As the rice mash content was increased, the succinic acid content also increased (p<0.05), but the citric acid content decreased significantly (p<0.05). In the sensory evaluation, strawberry jam with rice mash showed superior spreading property than that of the control sample. Strawberry jam with 0% rice mash had the highest color and taste score. For the overall acceptability, strawberry jams with 0% and, 14% of rice mash were preferable to that with 21%.

Optimal Condition for Simultaneous Saccharification and Fermentation Using Pretreated Corncob by Oxalic Acid (옥살산 전처리 옥수숫대를 이용한 동시당화발효 최적 조건 탐색)

  • Seo, Young-Jun;Lim, Woo-Seok;Lee, Jae-Won
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.6
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    • pp.490-497
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    • 2011
  • In this study, we determined optimal conditions for simultaneous saccharification and fermentation (SSF) using corncob biomass pretreated with oxalic acid. The effect of SSF temperature ($25.8{\sim}34.2^{\circ}C$) and agitation speed (80~220 rpm) were significant at a 99% confidence level in its effect on ethanol production. The highest ethanol production was expected when SSF was performed at $30^{\circ}C$, 170 rpm (22.5 g/L). The ethanol production was improved by mixture of yeast extract (1.25 g/L) and urea (1.25 g/L) as nitrogen source. However, addition of trace metal components and vitamin for SSF was not affected in the ethanol production. Optimal concentration of $KH_2PO_4$, $MgSO_4{\cdot}7H_2O$ for SSF was 1 g/L, 0.25 g/L respectively.