• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.173-178
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• 2009

Epidemiological studies showed that high trans-fat consumption is closely associated with getting the risks of cardiovascular disease. The objective of this study was to produce trans-free fat through lipase-catalyzed interesterification, as a substitute for the cream margarine commonly used in industry. Optimum conditions for interesterification in a packed bed enzyme bioreactor (PBEB) were determined using response surface methodology (RSM) based on central composite design. Three kinds of reaction variables were chosen, such as substrate flow rate (0.4-1.2 mL/min), reaction temperature (60-70$^{\circ}C$), and ratio of fully hydrogenated canola oil (FHCO, 35-45%) to evaluate their effects on the degree of interesterification. Optimum conditions from the standpoint of solid fat content (SFC) were found to be as follows: 0.4 mL/min flow rate, 64.7$^{\circ}C$ reaction temperate, and 42.8% (w/w) ratio of FHCO, respectively. The half-life of immobilized lipase in PBEB with two stages at 60$^{\circ}C$ ($1^{st}$ stage) and 55$^{\circ}C$ ($2^{nd}$ stage) was about more than 30 days as estimated by extrapolating the incubation time course of tristearoyl glycerol (TS) conversion, whereas the half-life of the enzyme in PBEB with single stage at 65$^{\circ}C$ was only about 15 days. Finally, the results from SFC analysis suggest that trans-free fat produced in this study seems to be a suitable substitute for the cream margarine commonly used in industry.

• Food Science and Preservation
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• v.15 no.1
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• pp.58-65
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• 2008

The Acorn (Quercus acutissima CARRUTHERS), which contains a large quantity of tannin, should be developed as a processed food as the acorn is rich in natural antioxidants and other valuable components. Accordingly, acorn extraction conditions for polyphenol and gallic acid (both antioxidants) were investigated by response surface methodology. The content of polyphenols were determined under 16 different extraction conditions based upon a central composite design. The parameters varied over $30-70^{\circ}C$ of extraction temperature, 1-5 h of extraction time, and 5-25 mL/g of solvent ratio, Gallic acid extraction was optimal at $60-100^{\circ}C$ extraction temperature, 1-5 h of extraction time, and 5-25 mL/g of solvent ratio, Epicatechin content was highest at $56.77^{\circ}C$, 4.16 hand 22.38 mL/g. Catechin content was highest at $52.37^{\circ}C$, 2h and 23.59 mL/g. The maximum catechin content was $91.30{\mu}g/mL$. Epigallocatechin content was influenced by extraction temperature and time. The maximum epigallocatechin content was $1,066.56{\mu}g/mL$ at $61.42^{\circ}C$, 4.17h, and 9.25 mL/g. The maximum value of epicatechingallate content was $125.39{\mu}g/mL$ at $47.72^{\circ}C$, 3.04h, and 24.93mL/g. Epigallocatechingallate content was influenced principally by solvent ratio and the maximum content was $61.38{\mu}g/mL$ at $48.11^{\circ}C$, 2.96h, and 24.95mL/g. The total polyphenol content was maximal at $1,332.75{\mu}g/mL$, after extraction at $61.50^{\circ}C$, 4.24h, at 9.71mL/g. The higher the extraction temperature and the longer the extraction time, the greater the polyphenol content. Gallic acid content was highest, the maximal level was $30.51{\mu}g/mL$ after $65.84^{\circ}C$, 1.65h at 17.17 mL/g, and this was influenced principally by extraction time and solvent ratio.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.37-42
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• 2012

This study investigated the use of Geobacter lovleyi with TBOS(Tetrabutoxysilane) for TCE(Trichloroethylene) dechlorination. The TCE dechlorination by Geobacter lovleiy was mathematically described as the independent variables such as initial concentration of TCE, protein mass of Geobacter lovleyi and initial concentration of TOBS, and these were modeled by the use of response surface methodology(RSM). These experiments were carried out as a Box-Behnken Design(BBD) consisting of 15 experiments. The application of RSM yielded the following equation, which is empirical relationship for the dechlorination efficiency($Y_1$, %) of TCE and first order kinetic constant of TCE($Y_2,\;d^{-1}$) by independent variables in coded unit : $Y_1=-11.50X_1$(initial concentration of TCE) + $4.25X_2$(protein mass as Geobacter lovleyi injected mass) - $4.75X_3$(initial concentration of TBOS) - ${6.58X_1}^2$ - ${8.58X_2}^2$ + 93.67, $Y_2=-10.92X_1+5.06X_2-4.89X_3-{4.93X_3}^2-2.19X_1X_2+2.54X_1X_3-2.19X_2X_3+16.71$. In this case, the value of the adjusted determination coefficient(adjusted $R^2$= 0.975 and 0.934) were closed to 1, showing a high significance of the model. Statistical results showed the order of TCE dechlorination at experimental factors to be initial TCE concentration > initial TBOS concentration > protein mass, but the interaction effects were non-significant.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.173-182
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• 2017

This study was conducted to investigate the change of Aaster scaber antioxidative activity, total phenolic compounds and flavonoids during the blanching processes. With two parameters such as blanching time and temperature, response surface methodology and central composite design was used to study the combined effect of blanching time (90 to 162 sec) and blanching temperature (75 to $99^{\circ}C$). We found that antioxidative activity, total phenolic compounds and flavonoids during the blanching processes were influenced by blanching temperature and time. Within process condition, total phenolic compounds and flavonoids were extracted 3.00 - 35.48 mg/g and 2.35 - 8.38 mg/g, respectively. DPPH radical scavenging activity was 42.10 - 67.14%. The change of total phenolic compounds, flavonoids, and DPPH radical scavenging activity was dependent of blanching temperature more than time. The total phenolic compounds was increased as temperature rise, but flavonoids not. However, DPPH radical scavenging activity was increased during the blanching process.

• Food Science and Preservation
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• v.12 no.3
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• pp.216-222
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• 2005

This study was carried out to establish the preparation condition of muskmelon jam. A central composite design was applied to investigate effects of muskmelon paste content(40, 45, 50, 55, 60 g), fructose ratio of sugar(20, 35, 50, 65, $80\%$) and pectin addition(l, 2, 3, 4, 5 g). The maximum sugar content was 61.48 $^{\circ}$Brix in 41.04 g of muskmelon paste content, $48.10\%$ of fructose ratio of sugar and 2.12 g of pectin content. The maximum value of softness was 2.71 g in 45.06 g of muskmelon paste content, $79.46\%$ of fructose ratio of sugar and 2.71 g of pectin addition. The minimum value of jelly strength was $0.04\;g{\cdot}cm$ in 47.80 g of muskmelon paste content, $63.0\%$ of fructose ratio of sugar and 1.99 g of pectin addition. The maximum value of organoleptic overall palatability was 5.89 in 55.65 g of muskmelon paste content, $73.19\%$ of fructose ratio of sugar and 2.42 g of pectin addition. The optimum conditions predicted for each corresponding physicochemical and organoleptic properties of muskmelon jam were 55.2 g(muskmelon paste content), $76.3\%$(fructose ratio of sugar) and 2.5 g(pectin addition).

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.433-438
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• 2004

This study was conducted to develop a sweet pumpkin to intermediate materials for various processed foods and dried food having high quality. Factorial experiment design with three variables having three levels was adapted and response surface methodology was used to determine optimum conditions for osmotic dehydration of sweet pumpkin. The moisture content, weight reduction, moisture loss and solid gain after osmotic dehydration increased according to increasement of immersion temperature, concentration and time. The effect of concentration was more significant than that of temperature and time at given conditions. Sugar concentration and vitamin C content increased in accordance with increasement of immersion temperature, concentration and time during osmotic dehydration. Hardness was increased by increasing immersion time. The regression models showed very significant values and high correlation coefficients (R2) above 0.91, excepting hardness. The optimum condition for osmotic dehydration was 23$^{\circ}C$, 52$^{\circ}C$Brix and 80 min at the constricted conditions such as 60∼70% moisture content, above 3 mg/100 g vitamin C and more than 10 kg/$\textrm{cm}^2$ hardness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1430-1437
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• 2011

Synthesis conditions of cocoa butter equivalents were optimized using the response surface method (RSM) by interesterification of canola oil (Ca), palmitic ethyl ester (PEE), and stearic ethyl ester (StEE). The reaction was catalyzed by immobilized lipase (Lipozyme TLIM) from Thermomyces lanuginosa to produce structured lipids containing a composition of triacylglycerols similar to cocoa butter. Reaction conditions were optimized using D-optimal design with the three reaction factors of the substrate molar ratio of canola oil to palmitic ethyl ester and stearic ethyl ester (Ca : PEE : StEE=1:1:3, 1:1.66:5, 1:2:6, 1:2.33:7, 1:3:9, $X_1$), enzyme ratio (2~6%, $X_2$), and reaction time (30~270 min, $X_3$). The optimal conditions that minimized acyl-migration while maximizing 1-palmitoyl-2-oleoyl-3-stearoyl glycerol (POS), 1,3-distearoyl-2-oleoyl glycerol (SOS), and 1,3-dipalmitoyl-2-oleoyl glycerol (POP) were predicted, resulting in Ca : PEE : StEE=1:3:9, 6% of enzyme ratio, and 40 min of reaction time. The reaction product of structured lipids was synthesized again under the same conditions, showing 10.43 area% of acyl-migration, 25.31 area% of POS/PSO, 19.79 area% of SOS, and 11.22 area% of POP.

• Food Science and Preservation
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• v.15 no.6
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• pp.840-846
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• 2008

Microwave-assisted extraction (MAE) of grape seeds was performed under the different conditions based on a central composite design for independent variables of microwave power ($0{\sim}120\;W$), ethanol concentration ($0{\sim}100%$) and extraction time ($1{\sim}5\;min$). Response surface methodology (RSM) was used to predict the optimum extraction conditions for three dependent variables in grape seed extracts: total yield, total catechin and electron donating ability. Determination coefficients ($R^2$) of regression equations for the three dependent variables were higher than 0.9 (p < 0.01). The optimal MAE conditions to yield the maximum value of total catechin (434.16 mg%) were 122.76 W microwave power, 42.88% ethanol and 4.67 min extraction time. The superimposed contour maps for maximizing the three dependent variables indicated that the MAE condition ranges were 75150 W, 4060% ethanol and 3.55.0 min. The predicted values at the optimized conditions (6.72% total yield, 408.65 mg% total catechin, and 83.33% electron donation ability) were similar to the experimental values. The optimized MAE (112.5 W, 50% EtOH, 4.2 min) was more efficient than the conventional solvent extraction using 80% EtOH, $60^{\circ}C$ for 3h and 150 rpm.

• Journal of the Korean Society of Food Culture
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• v.17 no.1
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• pp.70-77
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• 2002

Jangachi(salted and fermented vegetable) has been made by Korean traditionally using several kinds of vegetables, which is a good source of variety of nutrients and vitamins. There are many methods for making Jangachi. Generally soy sauce Jangachi is made through two steps. First, as a pretreatment, vegetables are soaked in salt water. Second, soaked vegetables are fermented in various ingredients like soy sauce, sugar, garlic, ginger and so on. This study was performed to observe changes in contents of chemical components and sensory evaluation of pretreated perilla leaf. Perilla leaf was soaked in water with different levels of salt concentration(2, 5 and 8 %) and soaking time(1, 3 and 5 days). The optimal level of salt and soaking time was determined with the results of sensory evaluation by response surface methodology and analysis of composition. The moisture contents decreased as the levels of salt and soaking time increased. The moisture content of untreated sample was 87.5 % and when soaked for 5 days in the water of 8 % salt concentration, it became 78.27 %. pH of Perilla leaf was high in high levels of salt concentration and short soaking time. Total acidity was so opposite to pH that was low in high levels of salt concentration and short soaking time. In the water of 8 % salt concentration, total acidity was 0.14 % when soaked for 1 day, 0.20 % for 3 days and 0.30 % for 5 days. Salt contents became greater as the soaking time increased. As the results of puncture test, soaked Perilla leaf's toughness increased as the levels of salt increased and soaking time decreased. Among the sensory attributes, greenness increased as the levels of salt concentration increased when soaked for more than 3 days. Saltiness and bitterness became greater as the levels of salt concentration increased. Perilla flavor decreased with the short soaking time. Off-flavor increased with the increased levels of soaking time and decreased salt concentration when soaked for more than 3 days. Toughness decreased as the levels of soaking time increased. Crispness increased with the increased levels of salt concentration. The condition of pretreated Perilla was optimum when it soaked for 42 hours in 4 % salt concentration.