• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.247-255
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• 2014

$La_{0.8}Sr_{0.2}CuO_3$ powder with the perovskite structure was prepared as electrode catalyst using citrate method. Porous electrode was made with as-prepared catalyst, carbon as supporter and polytetrafluoroethylene (PTFE) as hydrophobic binder. As results of potentiostatic electrolysis with potential of -1.5~-2.5 V vs. Ag/AgCl in 0.1, 0.5 and 1.0 M KOH at 5 and $10^{\circ}C$ on the porous electrode, liquid products were methanol, ethanol, 2-propanol and 1, 2-butanol regardless reaction temperature, while gas products were methane, ethane and ethylene at $5^{\circ}C$, and methane, ethane and propane at $10^{\circ}C$ respectively. Optimal potentials for $CO_2$ reduction in the view of over all faradic efficiency were high values (-2.0 and -2.2 V) for gas products whereas low potential (-1.5 V) for liquid products regardless of concentration and temperature.

• Analytical Science and Technology
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• v.12 no.4
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• pp.326-331
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• 1999

The metabolites of 1,2,4-trimethylbenzene (TMB) were synthesized and determined by capillary electrophoresis (CE). The optimum conditions of CE for the separation and determination of 3,4-, 2,4-, 2,5-dimethylbenzoic acid and 3,4-, 2,4-, 2,5-dimethylhippuric acid from the rat urine were as following: the fused silica capillary($75{\mu}m$ i.d. ${\times}$ 36 cm length, 29 cm to detector) was used and kept at $15^{\circ}C$. The applied voltage was 10㎸ and compounds were detected at UV 210 mnm and 254 nm. The running electrolyte was 0.1 M phosphate buffer (pH 7) containing 15 mM of ${\beta}-CD$ and 3% of 2-propanol. The relative amount of the metabolite of 1,2,4-TMB in the rat urine was 56.7% of 3,4-isomer, 30.5% of 2,4-isomer and 12.8% of 2,5-isomer. This method can be applied to the analysis of TMB-metabolites in human urine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1579-1587
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• 2014

This study aimed to determine the quality characteristics of fermented wine using Nuruk according to the type of aging container (jar or stainless container) and aging time. Alcohol analysis was initiated at 40.4~39.3%, and alcohol contents in the jar and stainless container decreased as aging time increased. Volatile acid content slightly increased in the reduced pressure (RP) jar and stainless container and showed a different result in the atmospheric pressure (AP) container. Amount of acetic acid did not change either in the jar or stainless container as aging time increased. In the case of 2-thiobarbituric acid (TBA), RP was lower than AP after distillation, and TBA value did not change much either in the jar or stainless container. In the case of fusel alcohol by aging time, n-propanol content did not increase either in the jar or stainless container as aging time increased. Iso-butanol content was reduced in the jar but did not change in the stainless container. In the AP container, more aromatic components were measured on the 180th day of aging time than after distillation. High boiling point aromatic components increased in particular. In the stainless container, more aromatic components were generated on the 180th day of aging, but their amount was relatively lower than in the jar. In the jar aging sensory test, the sensory score at RP 50 cmHg was highest on the 180th day of aging. In the case of AP $80^{\circ}C$ liquor, sensory score on the 180th day was the most improved.

• KSBB Journal
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• v.20 no.6
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• pp.408-412
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• 2005

In a previous research, it has been found that it could be possible to increase the partial pressure of hydrogen and hydrogen yield by scavenging the $CO_2$ from the heads pace of reactor. In this research, the positive and negative effects of the $CO_2$ scavenging especially on the fate of by-products were investigated by a batch experiment. Production and conversion of by-products had critical relationships with hydrogen evolution and consumption. The maximum hydrogen fraction in the headspace was increased from 66.4 to 91.2% by removing the $CO_2$ in the headspace and the degradation rate of glucose was also enhanced. The removal of $CO_2$ effectively hindered the homoacetogenesis but caused several negative phenomena. The degradation of ethanol, one of the main products, was inhibited by the high partial pressure of hydrogen and/or the absence of $CO_2$. Also it was observed that other by-products such as propionate, propanol, acetone, etc. could not be degraded further after produced from glucose. On the other hand, solventogenesis was not observed in spite of the high hydrogen partial pressure apart from previous researches and it might hinder the excess production of acetate, which could cause overall inhibition. From this research, it could be implicated that the $CO_2$ scavenging method could be recommended if the fermentation was purposed to produce hydrogen and ethanol.

• Journal of Life Science
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• v.24 no.12
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• pp.1325-1329
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• 2014

Gugija (Lycii chinese Miller) is traditionally consumed as a Chinese medicinal material in food, tea, or alcoholic beverages. Gugija has beneficial healthy components, but it produces an off-flavor during storage. This study compared the flavor components of fresh-dried Gugija and stale-dried Gugija. The flavor compounds in one fresh sample (sample 1) and one stale sample (sample 2) were extracted by the simultaneous distillation and extraction method. The concentrated aroma extracts were analyzed and identified by gas chromatography-mass spectrometry. Forty-five compounds, including 17 aldehydes, 8 alcohols, 6 terpene compounds, 4 esters, 3 ketones, and 3 pyrazines, were isolated in sample 1. Thirty-four compounds, including 12 aldehydes, 3 alcohols, 5 terpene compounds, 2 esters, 3 ketones, 3 pyrazines, and 1 acid, were isolated in sample 2. The main aroma components of sample 1 were 2-methyl butanal, 2-methyl propanol having sweet odor, and hexanal, (Z)-3-hexenol having grass odor, and phenyl acetaldehyde, benzyl alcohol having floral odor, and alkyl pyrazines having nutty odor. These compounds were decreased in sample 2, and several compounds containing isovaleric acid, which has a disagreeable, rancid-cheese odor were found newley.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.423-427
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• 1997

The effect of different treatments on the quality and yield of purified agar produced from Gelidium amansii has been studied, and the extraction condition ol agar produced from G. amansii has been examined. The contents of ash, sulfate in agar produced from g. amansii collected from different places were $2.63\~2.92\%\;and\;1.38\~1.78\%$, respectively. Yields and gel strength of agar produced from G. amansii collected from different places were $31.6\~46.8\%\;and\;496\~887g/cm^2$, respectively. It was effective to extract agar at $120^{\circ}C\;for\;2\~3hrs$. Agar was purified by D.W. washing, EDTA washing, chitosan treatment, CPC treatment, PEG treatment, ethanol precipitation, acetone precipitation and propanol precipitation. The mineral contents of agar produced from Gelidium amansii were Na (2934ppm), Ca (2472ppm), Mg (2259ppm), K (2527ppm), P1(81.1ppm), Fe (66.4ppm), Al (71.7ppm), Zn (29.7ppm) and Pb (ND: not detected), respectively.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.910-914
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• 2007

In order to synthesize new bioactive compounds and contrasting agents, reactions of glycine and glutamic acid as an animo acid with paraformaldehyde and hypophosphorous acid were executed. Products are 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid 1 and 3,7-dihydroxy-3,7- dioxoperhydre-1,5,3,7-diazadiphosphocine-1,5-di-(2-glu taric acid) 3. 2-[5-(1,2-Dicarboxyethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7] diazadiphosphocan-1-yl]-succinic acid 2 by using aspartic acid was not obtained. Esterification of 3,7- dihydroxy-3,7-dioxoperkydro-1,5,3,7-diaza-diphosphocine-1,5-diacetic acid 1 by treatment of methanol, ethanol, and propanol were executed. 3,7-Dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3.7-dihydroxy-3,7-dioxoperhydro-1,5,3,f-diazadiphosphocine-1.5-diacetic acid ethyl ester 5, and 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6 were respectively synthesized in good yields. Continuously, we will try synthesis of novel compounds and evaluation of biological activity.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1079-1084
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• 2002

Changes in components of onion vinegar during two-stage fermentation were investigated. One sample group (A) was prepared with onion juice by extraction and concentration (15 brix), and the other group (B) was prepared using the same method but supplemented with sucrose. Comparison of glucose (4.1%), fructose (4.2%), and sucrose (0.6%) found in A as major sugars with those (3.2, 3.3, and 4.6%, respectively) of B showed a significant difference in sucrose concentration. During alcohol fermentation, S. kluyvery DJ97 consumed these sugars completely. At 36 hr of alcohol fermentation, concentrations of reducing and total sugars decreased to 0.5 and 0.8%, in A, and 0.4 and 0.6%, in B, respectively. No further changes were detected in the concentrations of these sugars thereafter. From 12 hr of fermentation, alcohol concentrations in groups A and B increased markedly, maximizing at 7.0% at 36 hr A and at 8.2% at 48 hr in B, and finally decreased thereafter in both groups. The detected alcohol components were ethanol, acetaldehyde, methanol, n-propyl alcohol, iso-butanol, and iso-amyl acohol. During acetic acid fermentation, the concentration of acetic acid as the major organic also increased significantly in both groups (4,776.72 and 4,894.93 mg% in A amd B, respectively). Other organic acid contents such as malic and succinic acids were higher in A than B. these results indicate that vinegar is better produced in onion extract with no sucrose supplementation based on its organic acid contents.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.812-824
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• 2020

Objective: The aim of this work was to assess the effect of fermented blueberry (FB; 2%, 4%, and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4℃ for 28 days. Methods: The antioxidant activity of FB was determined through radical-scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0%, 2%, 4%, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatment was also determined. Results: The half maximal inhibitory concentration indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p<0.05). Particularly, 4% and 6% FB-treated sausages had better oxidation inhibition effects. However, FB accelerated the reduction in thiol groups (p<0.05). Additionally, FB inhibits the excessive formation of aldehyde compounds; for example, hexanal, which may cause rancid flavors, decreased from 58.25% to 19.41%. FB also created 6 alcohols (i.e., 2-methyl-1-propanol, 3-methyl-1-butanol, and phenylethyl alcohol), 5 ester compounds (i.e., ethyl acetate, ethyl lactate, and ethyl hexanoate) and 3-hydroxy-2-butanone in the sausages that contribute to sausage flavors. The principal component analysis showed that the aroma profiles of sausages with and without FB are easily identified. Conclusion: The addition of FB could significantly reduce the lipid and protein oxidation and improve oxidative stability for storage. Also, adding FB could inhibit rancid flavors and contribute to sausage flavors.

• KSBB Journal
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• v.13 no.6
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• pp.706-717
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• 1998

Enzymatic synthesis of fructose-based sugar fatty acid esters, such as methyl fructoside oleic acid mono and diester, was investigated using methyl fructoside as a sugar starting material. For the production of methyl fructoside fatty acid monoester by solvent process, 2-methyl 2-propanol was found to be a god reaction medium resulting a higher yield and productivity due to its high sugar solubility. The yield and productivity of methyl fructoside oleic acid monoester were 70% and 12.6g/L-hr, respectively, when molar ratio of methyl fructoside, initial concentration of methyl fructoside, enzyme(Novozym 435) content, and reaction temperature were 3:1, 200g/L, 1%(w/v), and $60^{\circ}C$, respectively. Methyl fructoside oleic acid diester was prepared by lipase-catalyzed diacylation of methyl fructoside and oleic acid in the solvent-free process. Maximum yield of 98% and productivity of 140g/L-hr were achieved when molar ratio(methyl fructoside and oleic acid) of 1:2 enzyme content of 10%(w/v) and reaction temperature of $70^{\circ}C$ were applied for the operating conditions under a reduced pressure of 20∼200 mmHg.