• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.215-223
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• 2012

Response surface methodology(RSM) is a very useful statistical techniques for improving and optimizing the product process. By this reason, RSM has been utilized extensively in the industrial world, particularly in the circumstances where several product variables potentially influence some quality characteristic of the product. In order to estimate the optimal condition of product variables, an experiment is being conducted defining appropriate experimental region. However, this experimental region can vary with the experimental circumstances and choice of a researcher. Response surface designs can be classified, according to the shape of the experimental region, into spherical and cuboidal. In the spherical case, the design is either rotatable or very near-rotatable. The central composite design(CCD)s widely used in RSM is an example of 5-level and spherical design. The cuboidal CCDs(CCDs with ${\alpha}=1$) is appropriate when an experimental region is cuboidal but this design dose not satisfy the rotatability as it is not spherical. Practically, a 3-level spherical design is often required in the industrial world where various level of experiments are not available. Box-Behnken design(BBD)s are a most popular 3-level spherical designs for fitting second-order response surfaces and satisfy the rotatability but the experimental region does not vary with the number of variables. The new experimental design with expanded experimental region can be considered if the predicting response at the extremes are interested. This paper proposes a new 3-level spherical RSM which are constructed to expand the experimental region together with number of product variables.

• Clean Technology
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• v.30 no.2
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• pp.113-122
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• 2024

In order to better understand carbon dioxide recycling, the carbon dioxide capture characteristics of six different alkaline industrial by-products, including incineration ash, desulfurized gypsum, low-grade quicklime, and steelmaking slag were investigated using a laboratory-scale direct aqueous carbonation reactor. In addition to the dissolution characteristics of each sample, the main reaction structure was confirmed through thermogravimetric analysis before and after the reaction, and the reactive CaO content was also defined through thermogravimetric analysis. The carbon dioxide capture capacity and efficiency of quicklime were determined to be 473 g/kg and 86.9%, respectively, and desulfurized gypsum and incineration ash were also evaluated to be relatively high at 51.1 to 131.7 g/kg and 51.2 to 87.7%, respectively. On the other hand, the capture efficiency of steelmaking slag was found to be less than 10% due to the influence of the production and post-cooling conditions. Therefore, in order to apply the carbonation process to steelmaking slag, it is necessary to optimize the slag production conditions. Through this study, it was confirmed that the carbon dioxide capture characteristics of incineration ash, quicklime, and desulfurized gypsum are at levels suitable for carbonation processes. Furthermore, this study was able to secure basic data for resource development technology that utilize carbon dioxide conversion to produce calcium carbonate for construction materials.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.95-102
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• 2015

The Maillard reaction is a non-enzymatic reaction between amino and carbonyl groups. During milk processing, lactose reacts with milk protein through this reaction. Infant formulas (IFs) are milk-based products processed with heat-treatments, including spray-drying and sterilization. Because IFs contain higher Maillard reaction products (MRPs) than breast milk, formula-fed infants are subject to higher MRP exposure than breast milk-fed ones. In this study, we investigated the optimization of conditions for minimal MRP formation with the addition of $\small{L}$-carnitine ($\small{L}$-car), pyridoxine hydrochloride (PH), and $\small{DL}$-${\alpha}$-tocopheryl acetate (${\alpha}$-T) in an IF model system. MRP formation was monitored by response surface methodology using fluorescence intensity (FI) and 5-hydroxymethylfurfural (HMF) content. The optimal condition for minimizing the formation of MRPs was with $2.3{\mu}M$ $\small{L}$-car, $15.8{\mu}M$ PH, and $20.6{\mu}M$ ${\alpha}$-T. Under this condition, the predicted values were 77.4% FI and 248.7 ppb HMF.

• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.101-110
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• 1996

Using response surface methodology(RSM), the various conditions(agitation speed, air flow, glucose concentration) in jar fermentor culture were investigated to find the optimum conditions for maximum enzyme production. Central-composite-design was used to control the variable constant in the experiment. The glucose isomerase production of Steptomyces chibaensis J-59 was mostly affected by the air flow rate and glucose concentration. The estimated optimum conditions were as follows: 1% birchwood xylan, 1.5% CSL, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, pH 7.0; air flow, 2.2vvm; agitation speed, 587rpm; glucose concentration, 0.586%. Experimental values(7.43GIU/ml) for the enzyme production obtained from the given optimum conditions had a almost resemblane to response values(7.67GIU/ml) predicted by the RSM. The jar fermentor culture by the RSM produced xylose isomerase about 2.7 times as much as the baffled flask culture.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.746-752
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• 2018

In this study, an optimized process for the waste cooking oil based biodiesel production using microwave energy was designed by using Box-Behnken design model. The process variables were chosen as a mole ratio of the methanol to oil, microwave power, and reaction time. Fatty acid methyl ester (FAME) content was then measured. Through the results of basic experiments, the range of optimum operation variables for the Box-Behnken design model, such as the methanol/oil mole ratio and reaction time, were set as between 8 to 10 and between 4 to 6 min, respectively. Ranges of the microwave power were set as from 8 to 12 W/g for 1.30 mg of KOH/g, acid value, while from 10 to 14 W/g for 2.00 mg of KOH/g, acid value. The optimum methanol/oil mole ratio, microwave power, and reaction time were reduced to 7.58, 10.26 W/g, and 5.1 min, respectively, for 1.30 mg KOH/g of acid value. Also, the optimum methanol/oil mole ratio, microwave power, and reaction time were 7.78, 12.18 W/g, and 5.1 min, respectively, for 2.00 mg KOH/g of acid value. Predicted FAME contents were 98.4% and 96.3%, with error rates of less than 0.3%. Therefore, when the optimized process of biodiesel production using microwave energy was applied to the Box-Behnken design model, the low error rate could be obtained.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.348-355
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• 1998

The developments of various processed foods and the high quality dried fruits, in particular, are urgently needed for the enhancement of fruit consumption and their competitive values. Therefore, in this study, three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of kiwifruit. The relationships of moisture losses, solid gains, weight reductions, sugar contents, titratable acidities and vitamin C contents depending on changes with temperature, sugar concentration and immersion time were investigated. The moisture loss, solid gain, weight reduction and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Sugar content was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. Titratable acidity and vitamin C content were increased by decreasing temperature, immersion time and increasing concentration during osmotic dehydration. The regression models showed a significant lack of fit (P>0.05) and were highly significant with satisfying values of $R^2$. At the given conditions such as $66{\sim}69%$ moisture content, above $24^{\circ}Brix$ sugar content and more than 23 mg% vitamin C, the optimum condition for osmotic dehydration was $37^{\circ}C,\;55^{\circ}Brix$ and 1.5 hour.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.567-572
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• 1994

Diglyceride was prepared by reaction of hydrogenated beef tallow and glycerol (GL) in the presence of a Pseudomonas lipase. Both substrates were mixed at the ratio of GL/Triglyceride of 0.5 which is the stoichiometric molar ratio for the complete conversion of triglyceride (TG) to diglyceride (DG). DG can be obtained by solid phase-glycerolysis of hydrogenated beef tallow without use of organic solvents or emulsifiers by careful control of reaction temperature. Optimized reaction temperature condition was as follows: An initial incubation at$60^{\circ}C$ for 2h followed by the first temperature shift down to $55^{\circ}C$ for 4h, and then the second shift down to $50^{\circ}C$ for up to 3 days. There was a large decrease in the content of TG during the first $60^{\circ}C$ incubation for 2h. Even a prolonged incubation at $60^{\circ}C$ could not make a change of the composition of the reaction mixture at liquid state. By controlling the temperature lower than $60^{\circ}C$, reaction mixtures were solidified. The reaction temperature at $50^{\circ}C$ below the melting temperature of hydrogenaed beef tallow gave an 71% optimum yield of DG after 72h enzymatic glycerolysis and about 73% of total DG was 1,3-DG.

• Food Science and Preservation
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• v.12 no.6
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• pp.591-599
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• 2005

This study was conducted to optimize the extraction conditions from cabbage by a response surface methodology. In extraction conditions based on the central composite design with variations, the ratio of solvent to sample ($10\~30$mL/g), ethanol concentration ($0\~100\%$) and extraction temperature ($35\~95^{circ}C$) coefficients of determinations ($R^2$) were 0.8162(p<0.1), 0.8173(p<0.1), 0.9374(p<0.01) and 0.9116(p<0.05) in extraction yield, electron donating ability, tyrosinase inhibition and SOD-like ability, respectively. Estimated extraction conditions for the maximizing yield, electron donating ability and SOD-like ability were $15\~30$ mL/g in ratio of solvent to sample, $40\~80\%$; ethanol concentration, and $50\~90^{\circ}C$ ; extraction temperature. Predicted values at the optimum condition (25 mL/g solvent to sample, $50\%$ ethanol concentration and $70^{\circ}C$ in extraction temperature) were in good agreement with observed values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1647-1653
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• 2008

This study used response surface methodology (RSM) in an effort to optimize the water extraction conditions of Hypsizigus marmoreus in order to increase cytotoxicity activity of the extract. A central composite design was applied to investigate the effects of independent variables, which included the extraction temperature ($X_1$), extraction time ($X_2$), the ratio of solvent to sample ($X_3$) on dependent variables of the extracts, including extraction yield ($Y_1$) and protein content ($Y_2$). The estimated optimal conditions were as follows: $51.3^{\circ}C$ extraction temperature, 8.2 hrs extraction time, and 46.7 mL/g of solvent per sample. The extract (CE) was extracted at optimal condition and crude polysaccharides (CPS) were obtained from CE by ethanol precipitation, dialysis, and freeze drying. Neutral (NPS) and acidic (APS) fraction of polysaccharides were seperated from CPS by ion chromatography. The growth inhibitory effects of the APS (0.5 mg/mL) on AGS human cancer cells were 73.97%. CPS showed the highest growth inhibitory effects on HepG2 human cancer cell at 0.5 mg/mL. However all fraction polysaccharides from Hypsizigus marmoreus showed lower than 20% growth inhibition on SW480 human cancer cell.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.185-194
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• 2020

This study was conducted to find out the optimal extraction conditions to obtain extracts with a high content of ginsenosides and antioxidant activity using the ginseng berry. After extraction by stirring, ultrasound and microwave method using 70% ethanol and distilled water as solvents, the results of considering the content of ginsenoside Re and Rb1, total polyphenol content, antioxidant activity, and whether it is an environmentally friendly manufacturing method, it was confirmed that the microwave method using distilled water is good method of extraction. The optimization of extraction conditions for microwave method were made by response surface methodology (RSM). Microwave power (50 ~ 200 W, X1), solvent and ginseng berry ratio (5 ~ 20 times, X2) and the extraction time (30 ~ 120 s, X3) were used as independent variables. The model showed a good fit having a determination coefficient of the regression equation of 0.9 or more and a p-value less than 0.05. Estimated conditions for the maximized extraction of ginsenoside contents and total polyphenols were 200 w in microwave power, 20 times in solvent and ginseng berry ratio, and 90 s in extraction time. Predicted values at the optimum conditions were total polyphenols of 6.23 mg GAE/g, ginsenoside Re of 17.69 mg/g, and ginsenoside Rb1 of 16.01 mg/g. In the verification of the actual measurement the obtained values showed 6.33 mg GAE/g, 17.79 mg/g, and 15.59 mg/g, respectively, in good agreement with predicted values.