• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.134-142
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• 2013

The effect of modified atmosphere packaging (MAP; 30% $CO_2$+70% $N_2$ or 100% $N_2$) and an additive mixture (500 ppm rosemary extract, 3,000 ppm sodium acetate and 1,500 ppm calcium lactate) on the quality of pre-cooked hamburger patties during storage at $5^{\circ}C$ for 14 d was evaluated. The addition of the additive mixture reduced aerobic and anaerobic bacteria counts in both 30% $CO_2$-MAP (30% $CO_2$+70% $N_2$) and 100% $N_2$-MAP (p<0.05). The 30% $CO_2$-MAP was more effective to suppress the microbial growth than 100% $N_2$-MAP, moreover the 30% $CO_2$-MAP combined with additive mixture resulted in the lowest bacterial counts. The hamburger patties with additive mixture showed lower CIE $L^*$ and CIE $a^*$, and higher CIE $b^*$ than those with no additive mixture. The 30% $CO_2$-MAP tended to decrease the TBARS during storage regardless of the addition of additives. The use of 30% $CO_2$-MAP in combination with additives mixture was effective for maintaining the quality and extending the shelf-life of pre-cooked hamburger patties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.1
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• pp.25-31
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• 1988

The crude calcium acetate (CCA) was made from egg-shell and acetic acid to use the CCA as a coagulant for Tofu (soy bean curd). Amount of CCA. $CO_2$ and residue made from 5.6g egg-shell (average weight of a egg-shell) and 10% acetic acid(50m1) was 3.8g, $300{\pm}10ml(at\;25^{\circ}$ and 2.1g. respectively. Tofu formable minimum concentration of the CCA was about 0.14% similar to that of $CaCl_2$, $MgCl_2$. Volume, hardness, taste and content f protein and lipid of Tofu by addition of CCA were not significantly different in those of Tofu that magnesium chloride and calcium chloride were used.

• Food Science and Preservation
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• v.16 no.6
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• pp.789-796
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• 2009

Benzoic acid (BA) and sorbic acid (SA) are the preservatives most commonly used in food. Although BA and SA are generally safe, some previous studies have shown that consumption of excessive amounts of these food additives can be a health hazard. The aim of this study was to determine the amounts of BA and SA in processed foods in Korea. Different brands of fruit juice, yogurt, cheese, dried fruits, jam, and margarine were purchased at a local market in Daejeon, Korea. Samples were analyzed by high-performance liquid chromatography (HPLC) using a UV detector. Chromatographic separation was achieved with a C18 column. Methanol acetate buffer (pH 4.4) at a 35:65 v/v ratio was used as the initial mobile phase to elute BA and SA. The detector wavelength was set at 254 nm. The average test results observed for BA concentrations in fruit juice, yogurt, cheese, dried fruits, jam, and margarine were $40.26{\pm}0.02$, $2.07{\pm}0.06$, $0.02{\pm}0.09$, $0.36{\pm}08$, $265.30{\pm}0.02$, and $27.34{\pm}0.08\;mg/kg$, respectively. Average concentrations of SA in these samples were $0.92{\pm}0.06$, $1.06{\pm}0.07$, $7.30{\pm}0.01$, $14.14{\pm}0.08$, $25.65{\pm}0.06$, and $4.81{\pm}0.07\;mg/kg$, respectively. Thus, the average levels of BA and SA in the studied food items were lower than the KFDA-permitted limits. Moreover, the estimated daily intake of both BA and SA by a typical consumer were below the maximum recommended daily values.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.922-928
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• 2000

The effects of animal species and supplements on rumen fluid characteristics, plasma urea-N (PUN) concentration, plasma urea-N pool size, urea-N degradation in the gut and urea-N net flux (urea-N synthesis rate) were studied in goats and sheep, with some minor differences detected. The animals were fed either chopped rice straw ad libitum+200 g soybean meal (SBM), or chopped rice straw ad libitum+190 g soybean meal+300 g sago meal (SBM+SM) for 14 days. The supplements were isonitrogenous (80 g crude protein/animal/d). [$^{14}C$]-urea was used as the marker for urea metabolism studies. Two animals from each species were fed either supplement in a cross-over design in two periods. The results showed that rumen pH was significantly (p<0.001) lower in animals fed SBM+SM than those fed SBM supplement. The ammonia concentrations of rumen fluid were significantly (p<0.01) higher in sheep (382.9 mg N/L) than goats (363.1 mg N/L) when fed SBM supplement but lower (282.5 mg N/L) than that of goats (311.0 mg N/L) when fed SBM+SM supplement. Total VFA concentrations were significantly (p<0.05) higher in animals fed SBM+SM supplement than those fed SBM supplement. Goats had significantly (p<0.01) higher molar proportions of acetate (79.1, 77.7%, respectively) than sheep (75.8, 74.0%, respectively) in both supplements. The molar proportion of acetate was significantly (p<0.05) higher, while that of butyrate lower in animals fed SBM supplement than those fed SBM+SM supplement. In animals fed SBM supplement, the molar proportion of propionate was significantly (p<0.01) higher in sheep (18.0%) than in goats (15.6%), but in animals fed SBM+SM, the molar proportion of butyrate was significantly (p<0.01) higher (9.6%) in sheep than in goats (7.2%). Plasma urea-N concentration, plasma urea-N pool size, urea-N degradation in the gut, urea-N net flux and the fraction of urea-C from the blood entering the rumen were not significantly different between goats and sheep fed either supplement. However, PUN concentration was significantly (p<0.05) lower in animals fed SBM+SM supplement (average of 13.8 mg N/100 ml) than in those fed SBM supplement (average of 16.5 mg N/100 ml). The urea net flux was significantly (p<0.05) higher in goats (average of 14.5 g N/d) than sheep (average of 12.9 g N/d), and animals fed SBM supplement showed higher (average of 14.9 g N/d) urea net flux than animals fed SBM+SM supplement (average of 12.9 g N/d). A significant (p<0.05) positive correlation was observed between urea-N net flux and urea-N degradation; urea-N net flux and pool size; urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia in goats. While in sheep, significant (p<0.05) positive correlation was observed between urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia.

• Korean Journal of Microbiology
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• v.14 no.2
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• pp.84-94
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• 1976

Cellulase components, CMCase(Cx) and Avicelase$(C_1)$, were partially prueified, from the culture extract of a strain of Trichoderma koningii by column chromatography on DEAE-Sephadex A-50 and the step of gel filtration through Sphadex G-150, Optimum pH of CMCase was 5.2 and Avicelase showed the highest activity at pH 5.6 in acetate buffer. Optimal temperatures for activities of CMCase and Avicelase were $50^{\circ}C\;and\;60^{\circ}C, $ respectively. More than 70% of the activities of two enzymes were remained after heating at $60^{\circ}C$ for 30 min and Avicelase is more stable than any other fungal enzymes. The Michaelis constants, Km, of CMCase and Avicelase were 0.116% of CMC and 0.281% of avicel. And also the values of maximum velocity, Vmax, of CMCase and Avicelase were $23.20{\mu}g\;and\;2.54{\mu}g$ of reducing sugar per min. Of the metal ions tested against the activites of CMCase and Avicelase, $Cu^{++}, \; Hg^{++}, \;and\;Pb^{{++}$ are remarkably effective inhibitors. The molecular weights of Cx and $C_1$ component were estimated to be about 47, 000 and 61, 000 by gel filtration method.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.99-104
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• 1993

Two strains of the gram-negative acetic acid bacteria, Acetobacter sp. strain CS2- AND CS5, were isolated form the traditional raw rice wine vinegar of Haenam area. The strains oxidized ethanol to acetic acid and over-oxidized acetate and lactate to $CO^{2}$ and $H ^{2}$O. They produced 2-ketogluconic acid from glucose but did not produce .gamma.-pyrones from glucose and dihydroxyacetone from glycerol. The CS strains possessed ubiquinone-9 as a major isoprenoid quinone and contained straight-chain $C_{18 :1}$, $_C{16 : 0}$, and $C _{14 : 0}$ fatty acids. The DNA base composition of the CS2 and CS5 strains was 56.2 and 57.3 mole% G + C, respectively. The isolates were grown well on methanol, gluconate, erythritol, raffinose, dulcitol and xylitol as sole sources of carbon and energy which are different from those of other Acetobacter species and producedd acid from sucrose, glycerol, fructose, inositol, mannitol, and ribose.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.200-206
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• 1993

Structures of two polymorphs of ${\alpha},{\alpha}$-trehalose octaacetate monohydrate, $C_{28}H_{38}O_{19}\;{\cdot}\;H_2O$, have been studied by X-ray diffraction method. ${\alpha},{\alpha}$-trehalose (${\alpha}$-D-glucopyranosyl ${\alpha}$-D-glucopyranoside) is a nonreducing disaccharide. The polymorph I belongs to the monoclinic $P2_1$, and has unit cell parameters of a=10.725(l), b=15.110(4), c=11.199(5) ${\AA}$, ${\beta}=108.16(2)^{\circ}$ and Z=2. The polymorph II is orthorhombic $P2_12_12_1$, with a=13.684(4), b=15.802(4), c=17.990(9) ${\AA}$ and Z=4. The final R and R$_w$ values for monoclinic polymorph I are 0.043 and 0.048 and for orthorhombic polymorph II are 0.116 and 0.118, respectively. Those R values of polymorph II are high because the large thermal motions of acetyl groups and the poor quality of the crystal. The molecular conformations in the two polymorphs are similar. Both D-glucopyranosyl rings have chair $^4C_1$ conformations and atoms of glycosidic chain ${\alpha}(1{\rightarrow}1)$ linkage are coplanar. The primary acetate groups of the pyranose residues assume both gauche-trans conformations. The molecules of two polymorphs have pseudo-C$_2$ symmetry at glycosidic O(1) atom. The bond lengths and angles are normal compared with those in other acetylated sugar compounds. The molecules in the monoclinic crystal are held by the hydrogen bonds with the water molecules and by van der Waals forces.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.219-223
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• 1987

A slightly modified method of Rashid and Potts(1980) to determine riboflavin in milk in which lead acetate was used as a precipitant was employed in tile present study to test applicability to determine that of fish as well. The lead acetate method was found to be sensitive, simple, inexpensive and rapid compared to the modified A.O.A.C. method by Cordon et al. (1979). But higher riboflavin values were obtained in this study than those reported so far. The riboflavin contents of 9 white fleshed fishes were in the range of $0.29\~0.48mg$ per 100g fresh sample. Linear regression equation Y=125.70X+0.71 (R=0.9993) was obtained for the calculation of riboflavin content in the white fleshed fish. Y is the concentration of riboflavin in the final solution to be chocked its OD at fluorometer and X is the dial reading of fluorometer. The stability of riboflavin as the freshness changes during icing storage$(at\;0^{\circ}C)$ was studied with file fish. During the initial stage of storage, the riboflavin content was found to by increased by $14\%$, but the difference was not statistically significant (p>0.05). K-value and VBN-value were increased along with storage time, but Proximate composition was not changed significantly during entire storage of 18 days.

• Journal of Life Science
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• v.29 no.4
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• pp.492-498
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• 2019

Previously, three kinds of lipases, lipAD1, lipAD2, and lipAD3, and lipase chaperone, lipBD, of Acinetobacter schindleri DYL129 isolated from soil sample were reported. In this report, three lipase and lipase chaperone were cloned into the pET32a(+) or pGEX-6P-1 vectors for protein expression in Escherichia coli, and named as pETLAD1, pETLAD2, pETLAD3 and pETLBD or pGEXLAD1, pGEXLAD 2, pGEXLAD3 and pGEXLBD, respectively. Protein expression rate was higher in pET system than in pGEX system. Although LipAD1 and LipAD2 were produced as inclusion bodies, their expression levels were high. So LipAD1 and LipAD2 could be solubilized in 8 M urea buffer and purified. LipAD3 and LipBD were overexpressed in soluble form and purified. Those proteins were purified by His-tag affinity chromatography connected in AKTA prime system. The activities of the purified lipases were demonstrated with 1% tributyrin agar plate. After purification, molecular mass was determined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. LipAD1 showed high activity toward ${\rho}$-nitrophenyl acetate and ${\rho}$-nitrophenyl butyrate, LipAD2 showed high activity toward ${\rho}$-nitrophenyl acetate and ${\rho}$-nitrophenyl myristate, and LipAD3 showed high activity toward ${\rho}$-nitrophenyl acetate, ${\rho}$-nitrophenyl butyrate, and ${\rho}$-nitrophenyl miristate, respectively. Three lipases, LipAD1, LipAD2, and LipAD3, showed optimal reaction at $50^{\circ}C$ using ${\rho}$-nitrophenyl butyrate, as substrate.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.7-14
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• 2000

A Bi$_{4}$Ti$_{3}$O$_{12}$ (BIT) thin film is prepared by sol-gel method using acetate precursors and evaluated whether it could be applied to NVFRAM (Non-Volatile Ferroelectric RAM). The drying and the annealing temperature are 40$0^{\circ}C$ and $650^{\circ}C$, respectively and they are determined from the DT-TG (Differential Thermal-Thermal Gravimetric) analysis. The BIT thin film deposited on Pt/Ta/SiO$_{2}$/Si substrate shows orthorhombic perovskite phase. The grain size and the surface roughness are about 100 nm and 70.2$\AA$, respectively. The dielectric constant and the loss tangent at 10 KHz are 176 and 0.038, respectively, and the leakage current density at 100 ㎸/cm is 4.71 $mutextrm{A}$/$\textrm{cm}^2$. In the results of hysteresis loops measured at $\pm$250 ㎸/cm, the remanent polarization (Pt) and the coercive field (Ec) are 5.92 $\mu$C/$\textrm{cm}^2$ and 86.3 ㎸/cm, respectively. After applying 10$^{9}$ square pulses of $\pm$5V, the remanent polarization of the BIT thin film decreases as much as about 33% from 5.92 $\mu$C/$\textrm{cm}^2$ of initial state to 3.95 $\mu$C/$\textrm{cm}^2$.